HarmonyOS 长按与拖拽冲突问题？

Question

build() {
  Column({ space: 5 }) {
    Column() {
      Grid(this.scroller) {
        ForEach(this.numbers, (day: string, index: number) => {
          GridItem() {
            Text(day)
              .fontSize(16)
              .backgroundColor(0xF9CF93)
              .width('100%')
              .height(70)
              .textAlign(TextAlign.Center)
          }.id('t'+day)
        })
      }
      .columnsTemplate('1fr 1fr 1fr 1fr')
      .columnsGap(10)
      .rowsGap(10)
      .onScrollIndex((first: number) => {
        console.info(first.toString())
      })
      .width('90%')
      .backgroundColor(0xFAEEE0)
      .supportAnimation(this.bo) // 设置支持拖拽动画
      .editMode(true) //设置Grid是否进入编辑模式，进入编辑模式可以拖拽Grid组件内部GridItem
      .onItemDragStart((event: ItemDragInfo, itemIndex: number) => { //第一次拖拽此事件绑定的组件时，触发回调。
        //index 0-3的元素不允许拖动
        if (itemIndex < 4) {
          return
        }
        this.text = this.numbers[itemIndex]
        this.itemWidth = this.scroller.getItemRect(itemIndex).width
        return this.pixelMapBuilder() //设置拖拽过程中显示的图片。
      })
      .onItemDragMove((event: ItemDragInfo, itemIndex: number, insertIndex: number) => { //拖拽在网格元素范围内移动时触发
        // 获取即将插入的子组件的位置来判断是否更改supportAnimation属性
        let yy = this.scroller.getItemRect(insertIndex).y
        if (yy==0 && this.bo){ // 前四个在第一行不移动，所以判断==0。 依次类推第二行第三行根据高度计算
          this.bo=false
        }else if (yy>0 && !this.bo){
          this.bo=true;
        }
        console.info('yy：'+yy)
      })
      .onItemDrop((event: ItemDragInfo, itemIndex: number, insertIndex: number, isSuccess: boolean) => { //绑定此事件的组件可作为拖拽释放目标，当在本组件范围内停止拖拽行为时，触发回调。
        // isSuccess=false时，说明drop的位置在grid外部；insertIndex > length时，说明有新增元素的事件发生
        if (!isSuccess || insertIndex >= this.numbers.length) {
          return
        }
        // index为0-3的元素不允许替换
        if (insertIndex <4) {
          return
        }
        console.info('测试' + itemIndex + '', insertIndex + '') //itemIndex拖拽起始位置，insertIndex拖拽插入位置
        this.changeIndex(itemIndex, insertIndex)
      })
    }
  }.width('100%').margin({ top: 5 })
}
}

Answer 1

请参考：

import curves from '@ohos.curves';
import Curves from '@ohos.curves'
@Entry
@Component
struct ListItemExample {
  @State private arr: number[] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
  @State dragItem: number = -1
  @State scaleItem: number = -1
  @State neighborItem: number = -1
  @State neighborScale: number = -1
  private dragRefOffset: number = 0
  @State offsetX: number = 0
  @State offsetY: number = 0
  private ITEM_INTV: number = 120
  scaleSelect(item: number): number {
    if (this.scaleItem == item) {
      return 1.05
    } else if (this.neighborItem == item) {
      return this.neighborScale
    } else {
      return 1
    }
  }
  itemMove(index: number, newIndex: number): void {
    let tmp = this.arr.splice(index, 1)
    this.arr.splice(newIndex, 0, tmp[0])
  }
  build() {
    Stack() {
      List({ space: 20, initialIndex: 0 }) {
        ForEach(this.arr, (item: number) => {
          ListItem() {
            Text('' + item)
              .width('100%')
              .height(100)
              .fontSize(16)
              .textAlign(TextAlign.Center)
              .borderRadius(10)
              .backgroundColor(0xFFFFFF)
              .shadow(this.scaleItem == item ? { radius: 70, color: '#15000000', offsetX: 0, offsetY: 0 } :
                { radius: 0, color: '#15000000', offsetX: 0, offsetY: 0 })
              .animation({ curve: Curve.Sharp, duration: 300 })
          }
          .margin({ left: 12, right: 12 })
          .scale({ x: this.scaleSelect(item), y: this.scaleSelect(item) })
          .zIndex(this.dragItem == item ? 1 : 0)
          .translate(this.dragItem == item ? { y: this.offsetY } : { y: 0 })
          // 以下组合手势为顺序识别，当长按手势事件未正常触发时则不会触发拖动手势事件

          .gesture(
            // 以下组合手势为顺序识别，当长按手势事件未正常触发时则不会触发拖动手势事件
            GestureGroup(GestureMode.Sequence,
              LongPressGesture({ repeat: true })
                .onAction((event?: GestureEvent) => {
                  animateTo({ curve: Curve.Friction, duration: 300 }, () => {
                    this.scaleItem = item
                  })

                })
                .onActionEnd(() => {
                  animateTo({ curve: Curve.Friction, duration: 300 }, () => {
                    this.scaleItem = -1
                  })
                })
              ,
              PanGesture({ fingers: 1, direction: null, distance: 0 })
                .onActionStart(() => {
                  this.dragItem = item
                  this.dragRefOffset = 0
                })
                .onActionUpdate((event: GestureEvent) => {
                  this.offsetY = event.offsetY - this.dragRefOffset
                  // console.log('Y:' + this.offsetY.toString())
                  this.neighborItem = -1
                  let index = this.arr.indexOf(item)
                  let curveValue = Curves.initCurve(Curve.Sharp)
                  let value: number = 0
                  //根据位移计算相邻项的缩放
                  if (this.offsetY < 0) {
                    value = curveValue.interpolate(-this.offsetY / this.ITEM_INTV)
                    this.neighborItem = this.arr[index-1]
                    this.neighborScale = 1 - value / 20;
                    console.log('neighborScale:' + this.neighborScale.toString())
                  } else if (this.offsetY > 0) {
                    value = curveValue.interpolate(this.offsetY / this.ITEM_INTV)
                    this.neighborItem = this.arr[index+1]
                    this.neighborScale = 1 - value / 20;
                  }
                  //根据位移交换排序
                  if (this.offsetY > this.ITEM_INTV / 2) {
                    animateTo({ curve: curves.interpolatingSpring(0, 1, 400, 38) }, () => {
                      this.offsetY -= this.ITEM_INTV
                      this.dragRefOffset += this.ITEM_INTV
                      this.itemMove(index, index + 1)
                    })
                  } else if (this.offsetY < -this.ITEM_INTV / 2) {
                    animateTo({ curve: curves.interpolatingSpring(0, 1, 400, 38) }, () => {
                      this.offsetY += this.ITEM_INTV
                      this.dragRefOffset -= this.ITEM_INTV
                      this.itemMove(index, index - 1)
                    })
                  }
                })
                .onActionEnd((event: GestureEvent) => {
                  animateTo({ curve: curves.interpolatingSpring(0, 1, 400, 38) }, () => {
                    this.dragItem = -1
                    this.neighborItem = -1
                  })
                  animateTo({
                    curve: curves.interpolatingSpring(14, 1, 170, 17), delay: 150
                  }, () => {
                    this.scaleItem = -1
                  })
                })
            )
              .onCancel(() => {
                animateTo({ curve: curves.interpolatingSpring(0, 1, 400, 38) }, () => {
                  this.dragItem = -1
                  this.neighborItem = -1
                })
                animateTo({
                  curve: curves.interpolatingSpring(14, 1, 170, 17), delay: 150
                }, () => {
                  this.scaleItem = -1
                })
              })
          )
        }, (item: number) => item.toString())
      }
    }.width('100%').height('100%').backgroundColor(0xDCDCDC).padding({ top: 5 })
  }
}