harmony 鸿蒙Button

2022-08-09
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Button

The <Button> component can be used to create different types of buttons.

NOTE

This component is supported since API version 7. Updates will be marked with a superscript to indicate their earliest API version.

Child Components

This component can contain only one child component.

APIs

Button

Button(options?: {type?: ButtonType, stateEffect?: boolean})

Since API version 9, this API is supported in ArkTS widgets.

Parameters

Name	Type	Mandatory	Description
type	ButtonType	No	Button type. Default value: ButtonType.Capsule
stateEffect	boolean	No	Whether to enable the pressed effect on the click of the button. The value false means to disable the pressed effect. Default value: true NOTE When the pressed effect is enabled on the click of the button and the state style is set, the background color is aaplied based on the state style.

Button

Button(label?: ResourceStr, options?: { type?: ButtonType, stateEffect?: boolean })

Creates a button component based on text content. In this case, the component cannot contain child components.

Since API version 9, this API is supported in ArkTS widgets.

Parameters

Name	Type	Mandatory	Description
label	ResourceStr	No	Button text.
options	{ type?: ButtonType, stateEffect?: boolean }	No	For details, see Button.

Attributes

In addition to the universal attributes, the following attributes are supported.

Name	Type	Description
type	ButtonType	Button type. Default value: ButtonType.Capsule Since API version 9, this API is supported in ArkTS widgets.
stateEffect	boolean	Whether to enable the pressed effect on the click of the button. The value false means to disable the pressed effect. Default value: true Since API version 9, this API is supported in ArkTS widgets.
labelStyle¹⁰⁺	LabelStyle	Label style of the button.

ButtonType

Since API version 9, this API is supported in ArkTS widgets.

Name	Description
Capsule	Capsule-type button (the round corner is half of the height by default).
Circle	Circle button.
Normal	Normal button (without rounded corners by default).

NOTE - The rounded corner of a button is set by using borderRadius, rather than by using the border API. Only a rounded corner whose parameter is Length is supported. - For a button of the Capsule type, the borderRadius settings do not take effect, and the radius of its rounded corner is always half of the button height or width, whichever is smaller. - For a button of the Circle type, its radius is the value of borderRadius (if set) or the width or height (whichever is smaller). - The button text is set using the text style attributes. - Before setting the gradient color, you need to set backgroundColor to transparent.

LabelStyle¹⁰⁺

Name	Type	Mandatory	Description
overflow	TextOverflow	No	Display mode when the label text is too long. Text is clipped at the transition between words. To clip text in the middle of a word, add zero-width spaces between characters.
maxLines	number	No	Maximum number of lines in the label text. By default, text is automatically folded. If this attribute is specified, the text will not exceed the specified number of lines. If there is extra text, you can use textOverflow to specify how it is displayed.
minFontSize	number \|ResourceStr	No	Minimum font size of the label text. For the setting to take effect, this attribute must be used together with maxFontSize, maxLines, or layout constraint settings.
maxFontSize	number \|ResourceStr	No	Maximum font size of the label text. For the setting to take effect, this attribute must be used together with minFontSize, maxLines, or layout constraint settings.
heightAdaptivePolicy	TextHeightAdaptivePolicy	No	How the adaptive height is determined for the label text.
font	Font	No	Font of the label text.

Events

The universal events are supported.

Example

Example 1

// xxx.ets
@Entry
@Component
struct ButtonExample {
  build() {
    Flex({ direction: FlexDirection.Column, alignItems: ItemAlign.Start, justifyContent: FlexAlign.SpaceBetween }) {
      Text('Normal button').fontSize(9).fontColor(0xCCCCCC)
      Flex({ alignItems: ItemAlign.Center, justifyContent: FlexAlign.SpaceBetween }) {
        Button('OK', { type: ButtonType.Normal, stateEffect: true })
          .borderRadius(8)
          .backgroundColor(0x317aff)
          .width(90)
          .onClick(() => {
            console.log('ButtonType.Normal')
          })
        Button({ type: ButtonType.Normal, stateEffect: true }) {
          Row() {
            LoadingProgress().width(20).height(20).margin({ left: 12 }).color(0xFFFFFF)
            Text('loading').fontSize(12).fontColor(0xffffff).margin({ left: 5, right: 12 })
          }.alignItems(VerticalAlign.Center)
        }.borderRadius(8).backgroundColor(0x317aff).width(90).height(40)

        Button('Disable', { type: ButtonType.Normal, stateEffect: false }).opacity(0.4)
          .borderRadius(8).backgroundColor(0x317aff).width(90)
      }

      Text('Capsule button').fontSize(9).fontColor(0xCCCCCC)
      Flex({ alignItems: ItemAlign.Center, justifyContent: FlexAlign.SpaceBetween }) {
        Button('OK', { type: ButtonType.Capsule, stateEffect: true }).backgroundColor(0x317aff).width(90)
        Button({ type: ButtonType.Capsule, stateEffect: true }) {
          Row() {
            LoadingProgress().width(20).height(20).margin({ left: 12 }).color(0xFFFFFF)
            Text('loading').fontSize(12).fontColor(0xffffff).margin({ left: 5, right: 12 })
          }.alignItems(VerticalAlign.Center).width(90).height(40)
        }.backgroundColor(0x317aff)

        Button('Disable', { type: ButtonType.Capsule, stateEffect: false }).opacity(0.4)
          .backgroundColor(0x317aff).width(90)
      }

      Text('Circle button').fontSize(9).fontColor(0xCCCCCC)
      Flex({ alignItems: ItemAlign.Center, wrap: FlexWrap.Wrap }) {
        Button({ type: ButtonType.Circle, stateEffect: true }) {
          LoadingProgress().width(20).height(20).color(0xFFFFFF)
        }.width(55).height(55).backgroundColor(0x317aff)

        Button({ type: ButtonType.Circle, stateEffect: true }) {
          LoadingProgress().width(20).height(20).color(0xFFFFFF)
        }.width(55).height(55).margin({ left: 20 }).backgroundColor(0xF55A42)
      }
    }.height(400).padding({ left: 35, right: 35, top: 35 })
  }
}

button

Example 2

// xxx.ets
@Entry
@Component
struct SwipeGestureExample {
  @State count: number = 0

  build() {
    Column() {
      Text(`${this.count}`)
        .fontSize(30)
        .onClick(() => {
          this.count++
        })
      if (this.count <= 0) {
        Button('count is negative').fontSize(30).height(50)
      } else if (this.count % 2 === 0) {
        Button('count is even').fontSize(30).height(50)
      } else {
        Button('count is odd').fontSize(30).height(50)
      }
    }.height('100%').width('100%').justifyContent(FlexAlign.Center)
  }
}

ifButton

Example 3

// xxx.ets
@Entry
@Component
struct buttonTestDemo {
  @State txt: string = 'overflowTextOverlengthTextOverflow.Clip';
  @State widthShortSize: number = 200;

  build() {
    Row() {
      Column() {
        Button(this.txt)
          .width(this.widthShortSize)
          .height(100)
          .labelStyle({ overflow: TextOverflow.Clip,
            maxLines: 1,
            minFontSize: 20,
            maxFontSize: 20,
            font: {
              size: 20,
              weight: FontWeight.Bolder,
              family: 'cursive',
              style: FontStyle.Italic
            }
          })
          .fontSize(40)
      }
      .width('100%')
    }
    .height('100%')
  }
}