harmony 鸿蒙@ohos.measure (Text Measurement)

2023-06-24
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@ohos.measure (Text Measurement)

The measure module provides APIs for measuring text metrics, such as text height and width.

NOTE

The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.

Modules to Import

import measure from '@ohos.measure'

measure.measureText

measureText(options: MeasureOptions): number

Measures the width of the given single-line text.

System capability: SystemCapability.ArkUI.ArkUI.Full

Parameters

Name	Type	Mandatory	Description
options	MeasureOptions	Yes	Information about the measured text.

Return value

Type	Description
number	Text width. The unit is px.

Example

import measure from '@ohos.measure'
@Entry
@Component
struct Index {
  @State message: string = 'Hello World'
  @State textWidth : number = measure.measureText({
    textContent: "Hello word",
    fontSize: '50px'
  })
  build() {
    Row() {
      Column() {
        Text("The width of 'Hello World': " + this.textWidth)
      }
      .width('100%')
    }
    .height('100%')
  }
}

measure.measureTextSize¹⁰⁺

measureTextSize(options: MeasureOptions): SizeOptions

Measures the width of the given single-line text.

System capability: SystemCapability.ArkUI.ArkUI.Full

Parameters

Name	Type	Mandatory	Description
options	MeasureOptions	Yes	Information about the measured text.

Return value

Type	Description
SizeOption	Layout width and height occupied by the text. The unit is px.

Example

import measure from '@ohos.measure'
@Entry
@Component
struct Index {
  @State message: string = 'Hello World'
  textSize : SizeOptions = measure.measureTextSize({
    textContent: "Hello word",
    fontSize: '50px'
  })
  build() {
    Row() {
      Column() {
        Text("The width of 'Hello World': " + this.textSize.width)
        Text("The height of 'Hello World': " + this.textSize.height)
      }
      .width('100%')
    }
    .height('100%')
  }
}

MeasureOptions

Provides attributes of the measured text.

System capability: SystemCapability.ArkUI.ArkUI.Full

Name	Type	Mandatory	Description
textContent	string	Yes	Content of the measured text.
constraintWidth¹⁰⁺	number \|string \|Resource	No	Layout width of the measured text. The default unit is vp.
fontSize	number \|string \|Resource	No	Font size of the measured text. If the value is of the number type, the unit fp is used. Default value: 16fp NOTE The value cannot be a percentage.
fontStyle	number \|FontStyle	No	Font style of the measured text. Default value: FontStyle.Normal
fontWeight	number \|string \|FontWeight	No	Font width of the measured text. For the number type, the value ranges from 100 to 900, at an interval of 100. A larger value indicates a heavier font weight. The default value is 400. For the string type, only strings of the number type are supported, for example, 400, “bold”, “bolder”, “lighter”, “regular”, and “medium”, which correspond to the enumerated values in FontWeight. Default value: FontWeight.Normal
fontFamily	string \|Resource	No	Font family of the measured text. Default value: ‘HarmonyOS Sans’ Only the default font is supported.
letterSpacing	number \|string	No	Letter spacing of the measured text.
textAlign¹⁰⁺	number \|TextAlign	No	Horizontal alignment mode of the measured text. Default value: TextAlign.Start
overflow¹⁰⁺	number \|TextOverflow	No	Display mode when the measured text is too long.
maxLines¹⁰⁺	number	No	Maximum number of lines in the measured text.
lineHeight¹⁰⁺	number \|string \|Resource	No	Line height of the measured text.
baselineOffset¹⁰⁺	number \|string	No	Baseline offset of the measured text. Default value: 0
textCase¹⁰⁺	number \|TextCase	No	Case of the measured text. Default value: TextCase.Normal