@ohos.arkui.dragController (DragController)

The dragController module provides APIs for initiating drag actions. When receiving a gesture event, such as a touch or long-press event, an application can initiate a drag action and carry drag information therein.

NOTE

The initial APIs of this module are supported since API version 10. Newly added APIs will be marked with a superscript to indicate their earliest API version. The functionality of this module depends on UI context. This means that the APIs of this module cannot be used where the UI context is unclear. For details, see UIContext. You can preview how this component looks on a real device, but not in DevEco Studio Previewer.

Modules to Import

import { dragController } from "@kit.ArkUI";

dragController.executeDrag^(deprecated)

executeDrag(custom: CustomBuilder|DragItemInfo, dragInfo: DragInfo,callback:AsyncCallback<DragEventParam>): void

Initiates a drag action, with the object to be dragged and the drag information passed in. This API uses an asynchronous callback to return the result.

NOTE

This API is deprecated since API version 18. You are advised to use executeDrag instead on the obtained DragController object.

Since API version 11, you can use the getDragController API in UIContext to obtain the DragController object associated with the current UI context.

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.ArkUI.ArkUI.Full

Parameters

Name	Type	Mandatory	Description
custom	CustomBuilder |DragItemInfo	Yes	Object to be dragged. NOTE The global builder is not supported. If the Image component is used in the builder, enable synchronous loading, that is, set the syncLoad attribute of the component to true. The builder is used only to generate the image displayed during the current dragging. Changes to the builder, if any, apply to the next dragging, but not to the current dragging.
dragInfo	DragInfo	Yes	Drag information.
callback	AsyncCallback<DragEventParam>	Yes	Callback used to return the result.

Error codes

For details about the error codes, see Universal Error Codes.

ID	Error Message
401	Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2.Incorrect parameters types; 3. Parameter verification failed.
100001	Internal handling failed.

Example

NOTE

You are advised to use the getDragController API in UIContext to obtain the DragController object associated with the current UI context.

import { dragController } from "@kit.ArkUI";
import { unifiedDataChannel } from '@kit.ArkData';

@Entry
@Component
struct DragControllerPage {
  @State text: string = ''

  @Builder DraggingBuilder() {
    Column() {
      Text("DraggingBuilder")
        .fontColor(Color.White)
        .fontSize(12)
    }
    .width(100)
    .height(100)
    .backgroundColor(Color.Blue)
  }

  build() {
    Column() {
      Button('touch to execute drag')
        .margin(10)
        .onTouch((event?:TouchEvent) => {
          if(event){
            if (event.type == TouchType.Down) {
              let text = new unifiedDataChannel.PlainText()
              text.textContent = 'drag text'
              text.abstract = 'abstract'
              let unifiedData = new unifiedDataChannel.UnifiedData(text)

              let dragInfo: dragController.DragInfo = {
                pointerId: 0,
                data: unifiedData,
                extraParams: ''
              }
              class tmp{
                event:DragEvent|undefined = undefined
                extraParams:string = ''
              }
              let eve:tmp = new tmp()
              this.getUIContext().getDragController().executeDrag(()=>{this.DraggingBuilder()}, dragInfo, (err, eve) => { // You are advised to use this.getUIContext().getDragController().executeDrag().
                if(eve.event){
                  if (eve.event.getResult() == DragResult.DRAG_SUCCESSFUL) {
                    // ...
                  } else if (eve.event.getResult() == DragResult.DRAG_FAILED) {
                    // ...
                  }
                }
              })
            }
          }
        })
      Text(this.text)
        .height(100)
        .width(150)
        .margin({top:20})
        .border({color:Color.Black,width:1})
        .onDrop((dragEvent?:DragEvent)=>{
          if(dragEvent){
            let records: Array<unifiedDataChannel.UnifiedRecord> = dragEvent.getData().getRecords();
            let plainText: unifiedDataChannel.PlainText = records[0] as unifiedDataChannel.PlainText;
            this.text = plainText.textContent;
          }
        })
    }
    .width('100%')
    .height('100%')
  }
}

dragController.executeDrag^(deprecated)

executeDrag(custom: CustomBuilder|DragItemInfo, dragInfo: DragInfo): Promise<DragEventParam>

Initiates a drag action, with the object to be dragged and the drag information passed in. This API uses a promise to return the result.

NOTE

This API is deprecated since API version 18. You are advised to use executeDrag instead on the obtained DragController object.

Since API version 11, you can use the getDragController API in UIContext to obtain the DragController object associated with the current UI context.

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.ArkUI.ArkUI.Full

Parameters

Name	Type	Mandatory	Description
custom	CustomBuilder |DragItemInfo	Yes	Object to be dragged.
dragInfo	DragInfo	Yes	Drag information.

Return value

Type	Description
Promise<DragEventParam>	Promise used to return the result.

Error codes For details about the error codes, see Universal Error Codes.

ID	Error Message
401	Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2.Incorrect parameters types; 3. Parameter verification failed.
100001	Internal handling failed.

Example

NOTE

You are advised to use the getDragController API in UIContext to obtain the DragController object associated with the current UI context.

import { dragController } from "@kit.ArkUI"
import { image } from '@kit.ImageKit';
import { unifiedDataChannel } from '@kit.ArkData';

@Entry
@Component
struct DragControllerPage {
  @State pixmap: image.PixelMap|undefined = undefined
  @State text: string = ''

  @Builder DraggingBuilder() {
    Column() {
      Text("DraggingBuilder")
        .fontColor(Color.White)
    }
    .width(100)
    .height(100)
    .backgroundColor(Color.Blue)
  }

  @Builder PixmapBuilder() {
    Column() {
      Text("PixmapBuilder")
        .fontColor(Color.White)
        .fontSize(15)
    }
    .width(100)
    .height(100)
    .backgroundColor(Color.Blue)
  }

  aboutToAppear() {
    let pb: CustomBuilder = (): void => {
      this.PixmapBuilder()
    }
    this.getUIContext().getComponentSnapshot().createFromBuilder(pb).then((pix: image.PixelMap) => {
      this.pixmap = pix;
    })
  }

  build() {
    Column() {
      Button('touch to execute drag')
        .margin(10)
        .onTouch((event?:TouchEvent) => {
          if(event){
            if (event.type == TouchType.Down) {
              let text = new unifiedDataChannel.PlainText()
              text.textContent = 'drag text'
              text.abstract = 'abstract'
              let unifiedData = new unifiedDataChannel.UnifiedData(text)

              let dragInfo: dragController.DragInfo = {
                pointerId: 0,
                data: unifiedData,
                extraParams: ''
              }
              let dragItemInfo: DragItemInfo = {
                pixelMap: this.pixmap,
                builder: ()=>{this.DraggingBuilder()},
                extraInfo: "DragItemInfoTest"
              }

              class tmp{
                event:DragResult|undefined = undefined
                extraParams:string = ''
              }
              let eve:tmp = new tmp()
              this.getUIContext().getDragController().executeDrag(dragItemInfo, dragInfo) // You are advised to use this.getUIContext().getDragController().executeDrag().
                .then((eve) => {
                  if (eve.event.getResult() == DragResult.DRAG_SUCCESSFUL) {
                    // ...
                  } else if (eve.event.getResult() == DragResult.DRAG_FAILED) {
                    // ...
                  }
                })
                .catch((err:Error) => {
                })
            }
          }
        })
      Text(this.text)
        .height(100)
        .width(150)
        .margin({top:20})
        .border({color:Color.Black,width:1})
        .onDrop((dragEvent?:DragEvent)=>{
          if(dragEvent){
            let records: Array<unifiedDataChannel.UnifiedRecord> = dragEvent.getData().getRecords();
            let plainText: unifiedDataChannel.PlainText = records[0] as unifiedDataChannel.PlainText;
            this.text = plainText.textContent;
          }
        })
    }
    .width('100%')
    .height('100%')
  }
}

DragInfo

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.ArkUI.ArkUI.Full

Defines the attributes required for initiating a drag action and information carried in the dragging process.

Name	Type	Mandatory	Description
pointerId	number	Yes	ID of the touch point on the screen when dragging is started. The value is an integer ranging from 0 to 9.
data	unifiedDataChannel.UnifiedData	No	Data carried in the dragging process.
extraParams	string	No	Additional information about the drag action. Not supported currently. The default value is null.
touchPoint11+	TouchPoint	No	Coordinates of the touch point. If this parameter is not set, the touch point is centered horizontally and shifted downward by 20% from the top.
previewOptions11+	DragPreviewOptions	No	Processing mode of the drag preview and the display of the number badge during dragging.

dragController.createDragAction^(deprecated)

createDragAction(customArray: Array<CustomBuilder |DragItemInfo>, dragInfo: DragInfo): DragAction

Creates a drag action object for initiating drag and drop operations. You need to explicitly specify one or more drag previews, the drag data, and the drag handle point. If a drag operation initiated by an existing drag action object is not completed, no new object can be created, and calling the API will throw an exception. After the lifecycle of the drag action object ends, the callback functions registered on this object become invalid. Therefore, it is necessary to hold this object within a longer scope and replace the old value with a new object returned by createDragAction before each drag initiation.

NOTE This API is supported since API version 10 and deprecated since API version 18. You are advised to use createDragAction instead on the obtained DragController object.

Since API version 11, you can use the getDragController API in UIContext to obtain the DragController object associated with the current UI context.

For optimal drag and drop performance, limit the number of drag previews.

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.ArkUI.ArkUI.Full

Parameters

Name	Type	Mandatory	Description
customArray	Array<CustomBuilder |DragItemInfo>	Yes	Object to be dragged.
dragInfo	DragInfo	Yes	Drag information.

Return value

Type	Description
DragAction	DragAction object, which is used to subscribe to drag state changes and start the drag service.

Error codes

For details about the error codes, see Universal Error Codes.

ID	Error Message
401	Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2.Incorrect parameters types; 3. Parameter verification failed.
100001	Internal handling failed.

Example

NOTE

You are advised to use the getDragController API in UIContext to obtain the DragController object associated with the current UI context.

import { dragController } from "@kit.ArkUI";
import { image } from '@kit.ImageKit';
import { unifiedDataChannel } from '@kit.ArkData';

@Entry
@Component
struct DragControllerPage {
  @State pixmap: image.PixelMap|null = null
  @State text: string = ''
  private dragAction: dragController.DragAction|null = null;
  customBuilders:Array<CustomBuilder|DragItemInfo> = new Array<CustomBuilder|DragItemInfo>();
  @Builder DraggingBuilder() {
    Column() {
      Text("DraggingBuilder")
        .fontColor(Color.White)
        .fontSize(12)
    }
    .width(100)
    .height(100)
    .backgroundColor(Color.Blue)
  }

  build() {
    Column() {

      Column() {
        Text(this.text)
          .width('100%')
          .height('100%')
          .fontColor(Color.White)
          .fontSize(18)
          .onDrop((dragEvent?:DragEvent)=>{
            if(dragEvent){
              let records: Array<unifiedDataChannel.UnifiedRecord> = dragEvent.getData().getRecords();
              let plainText: unifiedDataChannel.PlainText = records[0] as unifiedDataChannel.PlainText;
              this.text = plainText.textContent;
            }
          })
      }
      .width(100)
      .height(100)
      .backgroundColor(Color.Red)
      .margin(10)

      Button('Drag Multiple Objects').onTouch((event?:TouchEvent) => {
        if(event){
          if (event.type == TouchType.Down) {
            console.info("muti drag Down by listener");
            this.customBuilders.splice(0, this.customBuilders.length);
            this.customBuilders.push(()=>{this.DraggingBuilder()});
            this.customBuilders.push(()=>{this.DraggingBuilder()});
            this.customBuilders.push(()=>{this.DraggingBuilder()});
            let text = new unifiedDataChannel.PlainText()
            text.textContent = 'drag text'
            let unifiedData = new unifiedDataChannel.UnifiedData(text)
            let dragInfo: dragController.DragInfo = {
              pointerId: 0,
              data: unifiedData,
              extraParams: ''
            }
            try{
              this.dragAction = this.getUIContext().getDragController().createDragAction(this.customBuilders, dragInfo) // You are advised to use this.getUIContext().getDragController().createDragAction().
              if(!this.dragAction){
                console.info("listener dragAction is null");
                return
              }
              this.dragAction.on('statusChange', (dragAndDropInfo: dragController.DragAndDropInfo)=>{
                if (dragAndDropInfo.status == dragController.DragStatus.STARTED) {
                  console.info("drag has start");
                } else if (dragAndDropInfo.status == dragController.DragStatus.ENDED){
                  console.info("drag has end");
                  if (!this.dragAction) {
                    return
                  }
                  this.dragAction.off('statusChange')
                }
              })
              this.dragAction.startDrag().then(()=>{}).catch((err:Error)=>{
                console.info("start drag Error:" + err.message);
              })
            } catch(err) {
              console.info("create dragAction Error:" + err.message);
            }
          }
        }
      }).margin({top:20})
    }
  }
}

DragAction¹¹⁺

Implements a DragAction object to subscribe to drag state changes and start the drag service.

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.ArkUI.ArkUI.Full

startDrag¹¹⁺

startDrag(): Promise<void>

Starts the drag service. This API uses a promise to return the result.

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.ArkUI.ArkUI.Full

Error codes

ID	Error Message
100001	Internal handling failed.

Example

NOTE

You are advised to use the getDragController API in UIContext to obtain the DragController object associated with the current UI context.

import { dragController } from "@kit.ArkUI";
import { unifiedDataChannel } from '@kit.ArkData';

@Entry
@Component
struct DragControllerPage {
  private dragAction: dragController.DragAction|null = null;
  customBuilders:Array<CustomBuilder|DragItemInfo> = new Array<CustomBuilder|DragItemInfo>();
  @Builder DraggingBuilder() {
    Column() {
      Text("DraggingBuilder")
        .fontColor(Color.White)
        .fontSize(12)
    }
    .width(100)
    .height(100)
    .backgroundColor(Color.Blue)
  }

  build() {
    Column() {
      Button('Touch to Drag').onTouch((event?:TouchEvent) => {
        if(event){
          if (event.type == TouchType.Down) {
            this.customBuilders.splice(0, this.customBuilders.length);
            this.customBuilders.push(()=>{this.DraggingBuilder()});
            let text = new unifiedDataChannel.PlainText()
            text.textContent = 'drag text'
            let unifiedData = new unifiedDataChannel.UnifiedData(text)
            let dragInfo: dragController.DragInfo = {
              pointerId: 0,
              data: unifiedData,
              extraParams: ''
            }
            try{
              this.dragAction = this.getUIContext().getDragController().createDragAction(this.customBuilders, dragInfo) // You are advised to use this.getUIContext().getDragController().createDragAction().
              if(!this.dragAction){
                console.info("listener dragAction is null");
                return;
              }
              this.dragAction.startDrag().then(()=>{}).catch((err:Error)=>{
                console.info("start drag Error:" + err.message);
              })
            } catch(err) {
              console.info("create dragAction Error:" + err.message);
            }
          }
        }
      }).margin({top:20})
    }
  }
}

on('statusChange')¹¹⁺

on(type: 'statusChange', callback: Callback<DragAndDropInfo>): void

Subscribes to drag state changes.

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.ArkUI.ArkUI.Full

Parameters

Name	Type	Mandatory	Description
type	string	Yes	Event type. The value is fixed at 'statusChange', which indicates the drag state change event.
callback	Callback<DragAndDropInfo>	Yes	Callback used to return a DragAndDropInfo instance.

Example

NOTE

You are advised to use the getDragController API in UIContext to obtain the DragController object associated with the current UI context.

import { dragController } from "@kit.ArkUI";
import { unifiedDataChannel } from '@kit.ArkData';

@Entry
@Component
struct DragControllerPage {
  private dragAction: dragController.DragAction|null = null;
  customBuilders:Array<CustomBuilder|DragItemInfo> = new Array<CustomBuilder|DragItemInfo>();
  @Builder DraggingBuilder() {
    Column() {
      Text("DraggingBuilder")
        .fontColor(Color.White)
        .fontSize(12)
    }
    .width(100)
    .height(100)
    .backgroundColor(Color.Blue)
  }

  build() {
    Column() {
      Button('touch to execute drag').onTouch((event?:TouchEvent) => {
        if(event){
          if (event.type == TouchType.Down) {
            this.customBuilders.splice(0, this.customBuilders.length);
            this.customBuilders.push(()=>{this.DraggingBuilder()});
            let text = new unifiedDataChannel.PlainText()
            text.textContent = 'drag text'
            let unifiedData = new unifiedDataChannel.UnifiedData(text)
            let dragInfo: dragController.DragInfo = {
              pointerId: 0,
              data: unifiedData,
              extraParams: ''
            }
            let func = (dragAndDropInfo: dragController.DragAndDropInfo) => {
              console.info("Register to listen on drag status", JSON.stringify(dragAndDropInfo));
            }
            try{
              this.dragAction = this.getUIContext().getDragController().createDragAction(this.customBuilders, dragInfo) // You are advised to use this.getUIContext().getDragController().createDragAction().
              if(!this.dragAction){
                console.info("listener dragAction is null");
                return;
              }
              // Subscribe to drag state changes. The information in func will be logged once a change is detected.
              this.dragAction.on('statusChange', func);
              this.dragAction.startDrag().then(()=>{}).catch((err:Error)=>{
                console.info("start drag Error:" + err.message);
              })
            } catch(err) {
              console.info("create dragAction Error:" + err.message);
            }
          }
        }
      }).margin({top:20})
    }
  }
}

off('statusChange')¹¹⁺

off(type: 'statusChange', callback?: Callback<DragAndDropInfo>): void

Unsubscribes from drag state changes.

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.ArkUI.ArkUI.Full

Parameters

Name	Type	Mandatory	Description
type	string	Yes	Event type. The value is fixed at 'statusChange', which indicates the drag state change event.
callback	Callback<DragAndDropInfo>	No	Callback to unregister. If this parameter is not specified, this API unregisters all callbacks for the specified event.

Example

NOTE

You are advised to use the getDragController API in UIContext to obtain the DragController object associated with the current UI context.

import { dragController } from "@kit.ArkUI";
import { unifiedDataChannel } from '@kit.ArkData';

@Entry
@Component
struct DragControllerPage {
  private dragAction: dragController.DragAction|null = null;
  customBuilders:Array<CustomBuilder|DragItemInfo> = new Array<CustomBuilder|DragItemInfo>();
  @Builder DraggingBuilder() {
    Column() {
      Text("DraggingBuilder")
        .fontColor(Color.White)
        .fontSize(12)
    }
    .width(100)
    .height(100)
    .backgroundColor(Color.Blue)
  }

  build() {
    Column() {
      Button('touch to execute drag').onTouch((event?:TouchEvent) => {
        if(event){
          if (event.type == TouchType.Down) {
            this.customBuilders.splice(0, this.customBuilders.length);
            this.customBuilders.push(()=>{this.DraggingBuilder()});
            let text = new unifiedDataChannel.PlainText()
            text.textContent = 'drag text'
            let unifiedData = new unifiedDataChannel.UnifiedData(text)
            let dragInfo: dragController.DragInfo = {
              pointerId: 0,
              data: unifiedData,
              extraParams: ''
            }
            let func = (dragAndDropInfo: dragController.DragAndDropInfo) => {
              console.info("Register to listen on drag status", JSON.stringify(dragAndDropInfo));
            }
            try{
              this.dragAction = this.getUIContext().getDragController().createDragAction(this.customBuilders, dragInfo) // You are advised to use this.getUIContext().getDragController().createDragAction().
              if(!this.dragAction){
                console.info("listener dragAction is null");
                return;
              }
              this.dragAction.on('statusChange', func);
              // Unsubscribe from drag state changes. The information in func will not be logged after a drag operation starts.
              this.dragAction.off('statusChange', func);
              this.dragAction.startDrag().then(()=>{}).catch((err:Error)=>{
                console.info("start drag Error:" + err.message);
              })
            } catch(err) {
              console.info("create dragAction Error:" + err.message);
            }
          }
        }
      }).margin({top:20})
    }
  }
}

DragAndDropInfo¹¹⁺

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.ArkUI.ArkUI.Full

Provides the data reported when the state changes during dragging.

Name	Type	Mandatory	Description
status	DragStatus	Yes	Current dragging state (started or ended).
event	DragEvent	Yes	Drag event corresponding to the current state. The drag event initiated by dragController only supports the APIs for obtaining the result and behavior, and is used exclusively for the dragging end state.
extraParams	string	No	Additional information about the drag action. Not supported currently. The default value is null.

DragStatus¹¹⁺

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.ArkUI.ArkUI.Full

Describes the dragging start and end states.

Name	Value	Description
STARTED	0	Dragging is started.
ENDED	1	Dragging ends.

AnimationOptions¹¹⁺

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.ArkUI.ArkUI.Full

Defines the attributes required for initiating a drag action and information carried in the dragging process.

Name	Type	Mandatory	Description
duration	number	No	Animation duration, in ms. Default value: 1000 NOTE - If this parameter is set to a value less than 0, the value 0 is used. - Floating-point values will be rounded down to integers. For example, if the value set is 1.2, 1 will be used.
curve	Curve |ICurve	No	Animation curve. Default value: Curve.EaseInOut

DragEventParam¹²⁺

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.ArkUI.ArkUI.Full

Represents the callback used to return the result after a drag ends.

Name	Type	Mandatory	Description
event	DragEvent	Yes	Drag event information that includes only the drag result.
extraParams	string	Yes	Additional information about the drag event.

dragController.getDragPreview^(deprecated)

getDragPreview(): DragPreview

Obtains the DragPreview object, which represents the preview displayed during a drag operation.

NOTE

This API is supported since API version 10 and deprecated since API version 18. You are advised to use getDragPreview instead on the obtained DragController object.

Since API version 11, you can use the getDragController API in UIContext to obtain the DragController object associated with the current UI context.

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.ArkUI.ArkUI.Full

Return value

Type	Description
DragPreview	DragPreview object. It provides the API for setting the preview style. It does not work in the OnDrop and OnDragEnd callbacks.

Example

For details, see animate.

DragPreview¹¹⁺

Implements a DragPreview object. This API does not work in the OnDrop and OnDragEnd callbacks.

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.ArkUI.ArkUI.Full

setForegroundColor¹¹⁺

setForegroundColor(color: ResourceColor): void

Sets the foreground color of the drag preview. This API does not work in the OnDrop and OnDragEnd callbacks. It can only be used on the object obtained through the getDragPreview() API.

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.ArkUI.ArkUI.Full

Parameters

Name	Type	Mandatory	Description
color	ResourceColor	Yes	Foreground color of the drag preview.

Example

For details, see animate.

animate¹¹⁺

animate(options: AnimationOptions, handler: () => void): void

Applies a foreground color animation to the drag preview. This API does not work in the OnDrop and OnDragEnd callbacks. It can only be used on the object obtained through the getDragPreview() API.

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.ArkUI.ArkUI.Full

Parameters

Name	Type	Mandatory	Description
options	AnimationOptions	Yes	Animation settings.
handler	() => void	Yes	Callback used to change attributes such as the background mask color.

Example

NOTE

You are advised to use the getDragController API in UIContext to obtain the DragController object associated with the current UI context.

1. In the EntryAbility.ets file, obtain the UI context and save it to LocalStorage.

import { AbilityConstant, UIAbility, Want } from '@kit.AbilityKit';
import { hilog } from '@kit.PerformanceAnalysisKit';
import { window, UIContext } from '@kit.ArkUI';

let uiContext: UIContext;
let localStorage: LocalStorage = new LocalStorage('uiContext');

export default class EntryAbility extends UIAbility {
storage: LocalStorage = localStorage;

onCreate(want: Want, launchParam: AbilityConstant.LaunchParam): void {
  hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onCreate');
}

onDestroy(): void {
  hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onDestroy');
}

onWindowStageCreate(windowStage: window.WindowStage): void {
  hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onWindowStageCreate');

  windowStage.loadContent('pages/Index', this.storage, (err, data) => {
    if (err.code) {
      hilog.error(0x0000, 'testTag', 'Failed to load the content. Cause: %{public}s', JSON.stringify(err) ?? '');
      return;
    }
    hilog.info(0x0000, 'testTag', 'Succeeded in loading the content. Data: %{public}s', JSON.stringify(data) ?? '');
    windowStage.getMainWindow((err, data) => {
      if (err.code) {
        hilog.error(0x0000, 'Failed to obtain the main window. Cause:' + err.message, '');
        return;
      }
      let windowClass: window.Window = data;
      uiContext = windowClass.getUIContext();
      this.storage.setOrCreate<UIContext>('uiContext', uiContext);
    })
  });
}
}

2. In the Index.ets file, call this.getUIContext().getSharedLocalStorage() to obtain the UI context and then use the DragController object obtained to perform subsequent operations.

import { unifiedDataChannel } from '@kit.ArkData';
import { hilog } from '@kit.PerformanceAnalysisKit';
import { dragController, curves, promptAction, UIContext } from "@kit.ArkUI";
import { image } from '@kit.ImageKit';
import { BusinessError } from '@kit.BasicServicesKit';

@Entry()
@Component
struct DragControllerPage {
@State pixmap: image.PixelMap|null = null;
storages = this.getUIContext().getSharedLocalStorage();

@Builder DraggingBuilder() {
  Column() {
    Text("DraggingBuilder")
      .fontColor(Color.White)
      .fontSize(12)
  }
  .width(100)
  .height(100)
  .backgroundColor(Color.Blue)
}

@Builder PixmapBuilder() {
  Column() {
    Text("PixmapBuilder")
  }
  .width(100)
  .height(100)
  .backgroundColor(Color.Blue)
}

build() {
  Column() {
    Button('Drag Here')
      .margin(10)
      .onDragEnter(() => {
      try {
        let uiContext: UIContext = this.storages?.get<UIContext>('uiContext') as UIContext;
        let previewObj: dragController.DragPreview = uiContext.getDragController().getDragPreview();
        let foregroundColor: ResourceColor = Color.Green;

        let previewAnimation: dragController.AnimationOptions = {
          curve: curves.cubicBezierCurve(0.2,0,0,1),
        }
        previewObj.animate(previewAnimation, () => {
          previewObj.setForegroundColor(foregroundColor);
        });
      } catch (error) {
        let msg = (error as BusinessError).message;
        let code = (error as BusinessError).code;
        hilog.error(0x0000, `show error code is ${code}, message is ${msg}`, '');
      }
    })
      .onDrop(() => {
        this.getUIContext().getPromptAction().showToast({duration: 100, message: 'Drag Success', bottom: 400})
      })
    Button('Drag').onTouch((event?:TouchEvent) => {
      if(event){
        if (event.type == TouchType.Down) {
          let text = new unifiedDataChannel.Text()
          let unifiedData = new unifiedDataChannel.UnifiedData(text)
          let dragInfo: dragController.DragInfo = {
            pointerId: 0,
            data: unifiedData,
            extraParams: ''
          }
          class tmp{
            event:DragEvent|undefined = undefined
            extraParams:string = ''
          }
          let eve:tmp = new tmp()
          this.getUIContext().getDragController().executeDrag(() => { // You are advised to usethis.getUIContext().getDragController().executeDrag().
            this.DraggingBuilder()
          }, dragInfo, (err , eve) => {
            hilog.info(0x0000, `ljx ${JSON.stringify(err)}`, '')
            if (eve && eve.event) {
              if (eve.event.getResult() == DragResult.DRAG_SUCCESSFUL) {
                hilog.info(0x0000, 'success', '');
              } else if (eve.event.getResult() == DragResult.DRAG_FAILED) {
                hilog.info(0x0000, 'failed', '');
              }
            }
          })
        }
      }
    }).margin({top:100})
  }
  .width('100%')
  .height('100%')
}
}

DragStartRequestStatus¹⁸⁺

Enumerates the states defining whether an application can initiate a drag operation.

Atomic service API: This API can be used in atomic services since API version 18.

System capability: SystemCapability.ArkUI.ArkUI.Full

Name	Value	Description
WAITING	0	The application is preparing data and cannot initiate a drag operation yet.
READY	1	The application has completed data preparation and is ready to initiate a drag operation.

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