vue-grid-layout移动卡片到页面底部时页面滚动条跟随滚动

问题描述：默认情况下 vue-grid-layout 移动卡片到页面底部时页面滚动条并不会跟随卡片滚动。

问题解决：

在 grid-item中的move事件中，获取到当前移动的元素，并使用scrollIntoView方法来实现滚动条跟随。
代码如下：

const moveEvent = (i: any) => {
  let cIdx = layout.value.findIndex(item => item.i === i)
  let el = gridItemRefs.value[cIdx].$el
  setTimeout(() => {
      el?.scrollIntoView({ behavior: "smooth", block: "end" })
  }, 300)
}

此时优化效果如下：

• 但是上面优化还有一个小问题，将卡片右移可以无效无限右移。
  所以根据元素的lastX来控制一下：

const moveEvent = (i: any) => {
  let cIdx = layout.value.findIndex(item => item.i === i)
  let el = gridItemRefs.value[cIdx].$el
  setTimeout(() => {
    console.log(gridItemRefs.value[cIdx].lastX, '===gridItemRefs.value[cIdx]');
    if (gridItemRefs.value[cIdx].lastX < 900) {
      el?.scrollIntoView({ behavior: "smooth", block: "end" })
    }
  }, 300)
}

---

同理，如果是从外层拖到元素进来，也可以使用 scrollIntoView来设置滚动条跟随。
代码如下：

const colNum = 12
const drag = (item: any) => {
  let parentRect = document.getElementById('content')?.getBoundingClientRect()!;
  let mouseInGrid = false;
  if (((mouseXY.x > parentRect.left) && (mouseXY.x < parentRect.right)) && ((mouseXY.y > parentRect.top) && (mouseXY.y < parentRect.bottom))) {
    mouseInGrid = true;
  }
  if (mouseInGrid === true && (layout.value.findIndex(item => item.i === 'drop')) === -1) {
    layout.value.push({
      x: (layout.value.length * 2) % (colNum || 12),
      y: layout.value.length + (colNum || 12), // puts it at the bottom
      w: item.w,
      h: item.h,
      i: 'drop',
    });
  }
  let index = layout.value.findIndex(item => item.i === 'drop');
  if (index !== -1) {
    try {
      gridItemRefs.value[layout.value.length - 1].$refs.item.style.display = "none";
    } catch {
    }
    let el = gridItemRefs.value[index];
    if (el) {
      setTimeout(() => {
        el.$el?.scrollIntoView({ behavior: "smooth", block: "nearest" })
      }, 300)
      el.dragging = { "top": mouseXY.y - parentRect.top, "left": mouseXY.x - parentRect.left };
      let new_pos = el.calcXY(mouseXY.y - parentRect.top, mouseXY.x - parentRect.left);

      if (mouseInGrid === true) {

        gridlayout.value.dragEvent('dragstart', 'drop', new_pos.x || 0, new_pos.y || 0, item.h, item.w);
        // dragEvent('dragstart', 'drop', new_pos.x || 0, new_pos.y || 0, defaultH, defaultW);
        DragPos.i = String(new Date().getTime());
        DragPos.x = layout.value[index].x;
        DragPos.y = layout.value[index].y;
        DragPos.w = layout.value[index].w;
        DragPos.h = layout.value[index].h;
      }
      if (mouseInGrid === false) {
        gridlayout.value.dragEvent('dragend', 'drop', new_pos.x || 0, new_pos.y || 0, item.h, item.w);
        // dragEvent('dragend', 'drop', new_pos.x || 0, new_pos.y || 0, defaultH, defaultW);
        layout.value = layout.value.filter(obj => obj.i !== 'drop');
      }
    }
  }
}
const dragend = () => {
  let parentRect = document.getElementById('content')?.getBoundingClientRect()!;
  let mouseInGrid = false;
  if (((mouseXY.x > parentRect.left) && (mouseXY.x < parentRect.right)) && ((mouseXY.y > parentRect.top) && (mouseXY.y < parentRect.bottom))) {
    mouseInGrid = true;
  }
  if (mouseInGrid === true) {
    gridlayout.value.dragEvent('dragend', 'drop', DragPos.x, DragPos.y, DragPos.h, DragPos.w);
    let delIndex = layout.value.findIndex(item => item.i === 'drop')
    layout.value.splice(delIndex, 1)
    // UNCOMMENT below if you want to add a grid-item
    layout.value.push({
      x: DragPos.x,
      y: DragPos.y,
      w: DragPos.w,
      h: DragPos.h,
      i: DragPos.i,
    });
    gridlayout.value.dragEvent('dragend', DragPos.i, DragPos.x, DragPos.y, DragPos.h, DragPos.w);
    try {
      gridItemRefs.value[layout.value.length - 1].$refs.item.style.display = "block";
    } catch {
    }
  }
}