Flex

The <Flex> component allows for flexible layout of child components.

NOTE

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

The <Flex> component adapts the layout of flex items during rendering. This may affect the performance. Therefore, you are advised to use <Column> or <Row> instead under scenarios where consistently high performance is required.

If the main axis of the <Flex> component is not set, it follows the size of the parent container. On the contrary, if the main axis of the <Column> or <Row> component is not set, it follows the size of their child component.

Child Components

Supported

APIs

Flex(value?: { direction?: FlexDirection, wrap?: FlexWrap, justifyContent?: FlexAlign, alignItems?: ItemAlign, alignContent?: FlexAlign })

Creates a standard <Flex> component.

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

Parameters

Name	Type	Mandatory	Default Value	Description
direction	FlexDirection	No	FlexDirection.Row	Direction in which child components are arranged in the <Flex> component, that is, the direction of the main axis.
wrap	FlexWrap	No	FlexWrap.NoWrap	Whether the <Flex> component has a single line or multiple lines. NOTE When wrapped onto multiple lines, the child elements on the new line are stacked in the direction based on the cross axis direction.
justifyContent	FlexAlign	No	FlexAlign.Start	Alignment mode of the child components in the <Flex> component along the main axis.
alignItems	ItemAlign	No	ItemAlign.Start	Alignment mode of the child components in the <Flex> component along the cross axis.
alignContent	FlexAlign	No	FlexAlign.Start	Alignment mode of the child components in a multi-line <Flex> component along the cross axis. This parameter is valid only when wrap is set to Wrap or WrapReverse.

Example

// xxx.ets
@Entry
@Component
struct FlexExample1 {
  build() {
    Column() {
      Column({ space: 5 }) {
        Text('direction:Row').fontSize(9).fontColor(0xCCCCCC).width('90%')
        Flex({ direction: FlexDirection.Row }) {
          Text('1').width('20%').height(50).backgroundColor(0xF5DEB3)
          Text('2').width('20%').height(50).backgroundColor(0xD2B48C)
          Text('3').width('20%').height(50).backgroundColor(0xF5DEB3)
          Text('4').width('20%').height(50).backgroundColor(0xD2B48C)
        }
        .height(70)
        .width('90%')
        .padding(10)
        .backgroundColor(0xAFEEEE)

        Text('direction:RowReverse').fontSize(9).fontColor(0xCCCCCC).width('90%')
        Flex({ direction: FlexDirection.RowReverse }) {
          Text('1').width('20%').height(50).backgroundColor(0xF5DEB3)
          Text('2').width('20%').height(50).backgroundColor(0xD2B48C)
          Text('3').width('20%').height(50).backgroundColor(0xF5DEB3)
          Text('4').width('20%').height(50).backgroundColor(0xD2B48C)
        }
        .height(70)
        .width('90%')
        .padding(10)
        .backgroundColor(0xAFEEEE)

        Text('direction:Column').fontSize(9).fontColor(0xCCCCCC).width('90%')
        Flex({ direction: FlexDirection.Column }) {
          Text('1').width('100%').height(40).backgroundColor(0xF5DEB3)
          Text('2').width('100%').height(40).backgroundColor(0xD2B48C)
          Text('3').width('100%').height(40).backgroundColor(0xF5DEB3)
          Text('4').width('100%').height(40).backgroundColor(0xD2B48C)
        }
        .height(160)
        .width('90%')
        .padding(10)
        .backgroundColor(0xAFEEEE)

        Text('direction:ColumnReverse').fontSize(9).fontColor(0xCCCCCC).width('90%')
        Flex({ direction: FlexDirection.ColumnReverse }) {
          Text('1').width('100%').height(40).backgroundColor(0xF5DEB3)
          Text('2').width('100%').height(40).backgroundColor(0xD2B48C)
          Text('3').width('100%').height(40).backgroundColor(0xF5DEB3)
          Text('4').width('100%').height(40).backgroundColor(0xD2B48C)
        }
        .height(160)
        .width('90%')
        .padding(10)
        .backgroundColor(0xAFEEEE)
      }.width('100%').margin({ top: 5 })
    }.width('100%')
  }
}

en-us_image_0000001219744189

// xxx.ets
@Entry
@Component
struct FlexExample2 {
  build() {
    Column() {
      Column({ space: 5 }) {
        Text('Wrap').fontSize(9).fontColor(0xCCCCCC).width('90%')
        Flex({ wrap: FlexWrap.Wrap }) {
          Text('1').width('50%').height(50).backgroundColor(0xF5DEB3)
          Text('2').width('50%').height(50).backgroundColor(0xD2B48C)
          Text('3').width('50%').height(50).backgroundColor(0xD2B48C)
        }
        .width('90%')
        .padding(10)
        .backgroundColor(0xAFEEEE)

        Text('NoWrap').fontSize(9).fontColor(0xCCCCCC).width('90%')
        Flex({ wrap: FlexWrap.NoWrap }) {
          Text('1').width('50%').height(50).backgroundColor(0xF5DEB3)
          Text('2').width('50%').height(50).backgroundColor(0xD2B48C)
          Text('3').width('50%').height(50).backgroundColor(0xF5DEB3)
        }
        .width('90%')
        .padding(10)
        .backgroundColor(0xAFEEEE)

        Text('WrapReverse').fontSize(9).fontColor(0xCCCCCC).width('90%')
        Flex({ wrap: FlexWrap.WrapReverse , direction:FlexDirection.Row }) {
          Text('1').width('50%').height(50).backgroundColor(0xF5DEB3)
          Text('2').width('50%').height(50).backgroundColor(0xD2B48C)
          Text('3').width('50%').height(50).backgroundColor(0xD2B48C)
        }
        .width('90%')
        .height(120)
        .padding(10)
        .backgroundColor(0xAFEEEE)
      }.width('100%').margin({ top: 5 })
    }.width('100%')
  }
}

en-us_image_0000001174264366

// xxx.ets
@Component
struct JustifyContentFlex {
  justifyContent : number

  build() {
    Flex({ justifyContent: this.justifyContent }) {
      Text('1').width('20%').height(50).backgroundColor(0xF5DEB3)
      Text('2').width('20%').height(50).backgroundColor(0xD2B48C)
      Text('3').width('20%').height(50).backgroundColor(0xF5DEB3)
    }
    .width('90%')
    .padding(10)
    .backgroundColor(0xAFEEEE)
  }
}

@Entry
@Component
struct FlexExample3 {
  build() {
    Column() {
      Column({ space: 5 }) {
        Text('justifyContent:Start').fontSize(9).fontColor(0xCCCCCC).width('90%')
        JustifyContentFlex({ justifyContent: FlexAlign.Start })

        Text('justifyContent:Center').fontSize(9).fontColor(0xCCCCCC).width('90%')
        JustifyContentFlex({ justifyContent: FlexAlign.Center })

        Text('justifyContent:End').fontSize(9).fontColor(0xCCCCCC).width('90%')
        JustifyContentFlex({ justifyContent: FlexAlign.End })

        Text('justifyContent:SpaceBetween').fontSize(9).fontColor(0xCCCCCC).width('90%')
        JustifyContentFlex({ justifyContent: FlexAlign.SpaceBetween })

        Text('justifyContent:SpaceAround').fontSize(9).fontColor(0xCCCCCC).width('90%')
        JustifyContentFlex({ justifyContent: FlexAlign.SpaceAround })

        Text('justifyContent:SpaceEvenly').fontSize(9).fontColor(0xCCCCCC).width('90%')
        JustifyContentFlex({ justifyContent: FlexAlign.SpaceEvenly })
      }.width('100%').margin({ top: 5 })
    }.width('100%')
  }
}

en-us_image_0000001174582854

// xxx.ets
@Component
struct AlignItemsFlex {
  alignItems : number

  build() {
    Flex({ alignItems: this.alignItems }) {
      Text('1').width('33%').height(30).backgroundColor(0xF5DEB3)
      Text('2').width('33%').height(40).backgroundColor(0xD2B48C)
      Text('3').width('33%').height(50).backgroundColor(0xF5DEB3)
    }
    .size({width: '90%', height: 80})
    .padding(10)
    .backgroundColor(0xAFEEEE)
  }
}

@Entry
@Component
struct FlexExample4 {
  build() {
    Column() {
      Column({ space: 5 }) {
        Text('alignItems:Auto').fontSize(9).fontColor(0xCCCCCC).width('90%')
        AlignItemsFlex({ alignItems: ItemAlign.Auto })

        Text('alignItems:Start').fontSize(9).fontColor(0xCCCCCC).width('90%')
        AlignItemsFlex({ alignItems: ItemAlign.Start })

        Text('alignItems:Center').fontSize(9).fontColor(0xCCCCCC).width('90%')
        AlignItemsFlex({ alignItems: ItemAlign.Center })

        Text('alignItems:End').fontSize(9).fontColor(0xCCCCCC).width('90%')
        AlignItemsFlex({ alignItems: ItemAlign.End })

        Text('alignItems:Stretch').fontSize(9).fontColor(0xCCCCCC).width('90%')
        AlignItemsFlex({ alignItems: ItemAlign.Stretch })

        Text('alignItems:Baseline').fontSize(9).fontColor(0xCCCCCC).width('90%')
        AlignItemsFlex({ alignItems: ItemAlign.Baseline })
      }.width('100%').margin({ top: 5 })
    }.width('100%')
  }
}

en-us_image_0000001174422904

// xxx.ets
@Component
struct AlignContentFlex {
  alignContent: number

  build() {
    Flex({ wrap: FlexWrap.Wrap, alignContent: this.alignContent }) {
      Text('1').width('50%').height(20).backgroundColor(0xF5DEB3)
      Text('2').width('50%').height(20).backgroundColor(0xD2B48C)
      Text('3').width('50%').height(20).backgroundColor(0xD2B48C)
    }
    .size({ width: '90%', height: 90 })
    .padding(10)
    .backgroundColor(0xAFEEEE)
  }
}

@Entry
@Component
struct FlexExample5 {
  build() {
    Column() {
      Column({ space: 5 }) {
        Text('alignContent:Start').fontSize(9).fontColor(0xCCCCCC).width('90%')
        AlignContentFlex({ alignContent: FlexAlign.Start })

        Text('alignContent:Center').fontSize(9).fontColor(0xCCCCCC).width('90%')
        AlignContentFlex({ alignContent: FlexAlign.Center })

        Text('alignContent:End').fontSize(9).fontColor(0xCCCCCC).width('90%')
        AlignContentFlex({ alignContent: FlexAlign.End })

        Text('alignContent:SpaceBetween').fontSize(9).fontColor(0xCCCCCC).width('90%')
        AlignContentFlex({ alignContent: FlexAlign.SpaceBetween })

        Text('alignContent:SpaceAround').fontSize(9).fontColor(0xCCCCCC).width('90%')
        AlignContentFlex({ alignContent: FlexAlign.SpaceAround })

        Text('alignContent:SpaceEvenly').fontSize(9).fontColor(0xCCCCCC).width('90%')
        AlignContentFlex({ alignContent: FlexAlign.SpaceEvenly })
      }.width('100%').margin({ top: 5 })
    }.width('100%')
  }
}

en-us_image_0000001174422906