Drag and Drop Control

The drag and drop control attributes set whether a component can respond to drag events.

NOTE

The APIs of this module are supported since API version 10. Updates will be marked with a superscript to indicate their earliest API version.

The ArkUI framework implements the drag and drop capability for the following components, allowing them to serve as the drag source (from which data can be dragged) or drop target (to which data can be dropped). To enable drag and drop for these components, you only need to set their draggable attribute to true.

• The following component supports drag actions by default: <Search>, <TextInput>, <TextArea>, <RichEditor>, <Text>, <Image>, <FormComponent>, <Hyperlink>

• The following component supports drop actions by default: <Search>, <TextInput>, <TextArea>, <Video>

You can also define drag responses by implementing common drag events.

To enable drag and drop for other components, you need to set the draggable attribute to true and implement data transmission in APIs such as onDragStart.

allowDrop

allowDrop(value: Array<UniformDataType>)

Type of data that can be dropped to the component.

System capability: SystemCapability.ArkUI.ArkUI.Full

Parameters

draggable

draggable(value: boolean)

Whether the component is draggable.

System capability: SystemCapability.ArkUI.ArkUI.Full

Parameters

dragPreview¹¹⁺

dragPreview(value: CustomBuilder | DragItemInfo)

Sets the preview displayed when the component is dragged

System capability: SystemCapability.ArkUI.ArkUI.Full

Parameters

dragPreviewOptions¹¹⁺

dragPreviewOptions(value: DragPreviewOptions)

Sets how the drag preview is processed when the component is dragged. This API works only for onDragStart.

System capability: SystemCapability.ArkUI.ArkUI.Full

Parameters

DragPreviewOptions¹¹⁺

DragPreviewMode¹¹⁺

Example

Example 1

Example of using the allowDrop and draggable attributes:

// xxx.ets
import UDC from '@ohos.data.unifiedDataChannel';
import UTD from '@ohos.data.uniformTypeDescriptor';

@Entry
@Component
struct ImageExample {
  @State uri: string = ""
  @State AblockArr: string[] = []
  @State BblockArr: string[] = []
  @State AVisible: Visibility = Visibility.Visible
  @State dragSuccess :Boolean = false

  build() {
    Column() {
      Text ('Image drag and drop')
        .fontSize('30dp')
      Flex({ direction: FlexDirection.Row, alignItems: ItemAlign.Center, justifyContent: FlexAlign.SpaceAround }) {
        Image($r('app.media.icon'))
          .width(100)
          .height(100)
          .border({ width: 1 })
          .visibility(this.AVisible)
          .draggable(true)
          .onDragEnd((event: DragEvent) => {
            let ret = event.getResult();
            if(ret == 0) {
              console.log("enter ret == 0")
              this.AVisible = Visibility.Hidden;
            } else {
              console.log("enter ret != 0")
              this.AVisible = Visibility.Visible;
            }
          })
      }
      .margin({ bottom: 20 })
      Row() {
        Column(){
          Text('Invalid drop target')
            .fontSize('15dp')
            .height('10%')
          List(){
            ForEach(this.AblockArr, (item:string, index) => {
              ListItem() {
                Image(item)
                  .width(100)
                  .height(100)
                  .border({width: 1})
              }
              .margin({ left: 30 , top : 30})
            }, (item:string) => item)
          }
          .height('90%')
          .width('100%')
          .allowDrop([UTD.UniformDataType.TEXT])
          .onDrop((event?: DragEvent, extraParams?: string) => {
            this.uri = JSON.parse(extraParams as string).extraInfo;
            this.AblockArr.splice(JSON.parse(extraParams as string).insertIndex, 0, this.uri);
            console.log("ondrop not udmf data");
          })
          .border({width: 1})
        }
        .height("50%")
        .width("45%")
        .border({ width: 1 })
        .margin({ left: 12 })
        Column(){
          Text ('Valid drop target')
            .fontSize('15dp')
            .height('10%')
          List(){
            ForEach(this.BblockArr, (item:string, index) => {
              ListItem() {
                Image(item)
                  .width(100)
                  .height(100)
                  .border({width: 1})
              }
              .margin({ left: 30 , top : 30})
            }, (item:string) => item)
          }
          .border({width: 1})
          .height('90%')
          .width('100%')
          .allowDrop([UTD.UniformDataType.IMAGE])
          .onDrop((event?: DragEvent, extraParams?: string) => {
            console.log("enter onDrop")
            let dragData:UnifiedData = (event as DragEvent).getData() as UnifiedData;
            if(dragData != undefined) {
              let arr:Array<UDC.UnifiedRecord> = dragData.getRecords();
              if(arr.length > 0) {
                let image = arr[0] as UDC.Image;
                this.uri = image.imageUri;
                this.BblockArr.splice(JSON.parse(extraParams as string).insertIndex, 0, this.uri);
              } else {
                console.log(`dragData arr is null`)
              }
            } else {
              console.log(`dragData  is undefined`)
            }
            console.log("ondrop udmf data");
            this.dragSuccess = true
          })
        }
        .height("50%")
        .width("45%")
        .border({ width: 1 })
        .margin({ left: 12 })
      }
    }.width('100%')
  }
}

Example 2

Example of using the dragPreview attribute:

// xxx.ets
@Entry
@Component
struct DragPreviewDemo{
  @Builder dragPreviewBuilder() {
    Column() {
      Text("dragPreview")
        .width(150)
        .height(50)
        .fontSize(20)
        .borderRadius(10)
        .textAlign(TextAlign.Center)
        .fontColor(Color.Black)
        .backgroundColor(Color.Pink)
    }
  }

  @Builder MenuBuilder() {
    Flex({ direction: FlexDirection.Column, justifyContent: FlexAlign.Center, alignItems: ItemAlign.Center }) {
      Text("menu item 1")
        .fontSize(15)
        .width(100)
        .height(40)
        .textAlign(TextAlign.Center)
        .fontColor(Color.Black)
        .backgroundColor(Color.Pink)
      Divider()
        .height(5)
      Text("menu item 2")
        .fontSize(15)
        .width(100)
        .height(40)
        .textAlign(TextAlign.Center)
        .fontColor(Color.Black)
        .backgroundColor(Color.Pink)
    }
    .width(100)
  }

  build() {
    Row() {
      Column() {
        Image('/resource/image.jpeg')
          .width("30%")
          .draggable(true)
          .bindContextMenu(this.MenuBuilder, ResponseType.LongPress)
          .onDragStart(() => {
            console.log("Image onDragStart")
          })
          .dragPreview(this.dragPreviewBuilder)
      }
      .width("100%")
    }
    .height("100%")
  }
}

Example 3

Example of using the dragPreviewOptions attribute:

// xxx.ets
@Entry
@Component
struct dragPreviewOptionsDemo{
  build() {
    Row() {
      Column() {
        Image('/resource/image.jpeg')
          .margin({ top: 10 })
          .width("100%")
          .draggable(true)
          .dragPreviewOptions({ mode: DragPreviewMode.AUTO })
      }
      .width("100%")
      .height("100%")
    }
  }
}