@ohos.arkui.dragController (DragController)

The dragController module provides APIs for initiating drag actions. When receiving a gesture event, such as a click 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.

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Modules to Import

import dragController from "@ohos.arkui.dragController";

dragController.executeDrag

executeDrag(custom: CustomBuilder | DragItemInfo, dragInfo: DragInfo, callback: AsyncCallback<{event: DragEvent, extraParams: string}>): 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.

System capability: SystemCapability.ArkUI.ArkUI.Full

Parameters

Example

import dragController from "@ohos.arkui.dragController"
import UDC from '@ohos.data.unifiedDataChannel';

@Entry
@Component
struct DragControllerPage {
  @Builder DraggingBuilder() {
    Column() {
      Text("DraggingBuilder")
    }
    .width(100)
    .height(100)
    .backgroundColor(Color.Blue)
  }

  build() {
    Column() {
      Button('touch to execute drag')
        .onTouch((event?:TouchEvent) => {
          if(event){
            if (event.type == TouchType.Down) {
              let text = new UDC.Text()
              let unifiedData = new UDC.UnifiedData(text)

              let dragInfo: dragController.DragInfo = {
                pointerId: 0,
                data: unifiedData,
                extraParams: ''
              }
              class tmp{
                event:DragEvent|undefined = undefined
                extraParams:string = ''
              }
              let eve:tmp = new tmp()
              dragController.executeDrag(()=>{this.DraggingBuilder()}, dragInfo, (err, eve) => {
                if(eve.event){
                  if (eve.event.getResult() == DragResult.DRAG_SUCCESSFUL) {
                  // ...
                  } else if (eve.event.getResult() == DragResult.DRAG_FAILED) {
                  // ...
                  }
                }
              })
            }
          }
        })
    }
  }
}

dragController.executeDrag

executeDrag(custom: CustomBuilder | DragItemInfo, dragInfo: DragInfo): Promise<{event: DragEvent, extraParams: string}>

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.

System capability: SystemCapability.ArkUI.ArkUI.Full

Parameters

Return value

Example

import dragController from "@ohos.arkui.dragController"
import componentSnapshot from '@ohos.arkui.componentSnapshot';
import image from '@ohos.multimedia.image';
import UDC from '@ohos.data.unifiedDataChannel';

@Entry
@Component
struct DragControllerPage {
  @State pixmap: image.PixelMap|null = null

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

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

  build() {
    Column() {
      Button('touch to execute drag')
        .onTouch((event?:TouchEvent) => {
          if(event){
            if (event.type == TouchType.Down) {
              let text = new UDC.Text()
              let unifiedData = new UDC.UnifiedData(text)

              let dragInfo: dragController.DragInfo = {
                pointerId: 0,
                data: unifiedData,
                extraParams: ''
              }
              let pb:CustomBuilder =()=>{():void=>{this.PixmapBuilder()}}
              componentSnapshot.createFromBuilder(pb).then((pix: image.PixelMap) => {
                this.pixmap = pix;
                let dragItemInfo: DragItemInfo = {
                  pixelMap: this.pixmap,
                  builder: ()=>{this.DraggingBuilder()},
                  extraInfo: "DragItemInfoTest"
                }

                class tmp{
                  event:DragResult|undefined = undefined
                  extraParams:string = ''
                }
                let eve:tmp = new tmp()
                dragController.executeDrag(dragItemInfo, dragInfo)
                  .then((eve) => {
                    if (eve.event.getResult() == DragResult.DRAG_SUCCESSFUL) {
                      // ...
                    } else if (eve.event.getResult() == DragResult.DRAG_FAILED) {
                      // ...
                    }
                  })
                  .catch((err:Error) => {
                  })
              })
            }
          }
        })
    }
    .width('100%')
    .height('100%')
  }
}

DragInfo

System capability: SystemCapability.ArkUI.ArkUI.Full

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