vue实现2行的方格，从鼠标按下触发的方格开始，拖动选中多个方格，到鼠标弹起触发的方格结束，只可选择一段且连续的方格。选中的放格颜色为红色，未选中为黑色

可以通过以下代码实现：

在 HTML 中：

<div id="app">
  <div v-for="(row, rowIndex) in rows" :key="rowIndex" class="row">
    <div v-for="(col, colIndex) in row" :key="colIndex" :class="{'col': true, 'selected': isSelected(rowIndex, colIndex)}" @mousedown="startSelection(rowIndex, colIndex)" @mouseover="select(rowIndex, colIndex)" @mouseup="endSelection">
      {{ col }}
    </div>
  </div>
</div>

在 JavaScript 中：

new Vue({
  el: '#app',
  data: {
    rows: [
      ['A', 'B', 'C', 'D', 'E'],
      ['F', 'G', 'H', 'I', 'J'],
      ['K', 'L', 'M', 'N', 'O'],
      ['P', 'Q', 'R', 'S', 'T'],
      ['U', 'V', 'W', 'X', 'Y']
    ],
    startRow: null,
    startCol: null,
    endRow: null,
    endCol: null
  },
  methods: {
    startSelection(row, col) {
      this.startRow = row;
      this.startCol = col;
      this.endRow = row;
      this.endCol = col;
    },
    select(row, col) {
      if (this.startRow !== null && this.startCol !== null) {
        this.endRow = row;
        this.endCol = col;
      }
    },
    endSelection() {
      this.startRow = null;
      this.startCol = null;
      this.endRow = null;
      this.endCol = null;
    },
    isSelected(row, col) {
      if (this.startRow === null || this.startCol === null || this.endRow === null || this.endCol === null) {
        return false;
      }
      const minRow = Math.min(this.startRow, this.endRow);
      const maxRow = Math.max(this.startRow, this.endRow);
      const minCol = Math.min(this.startCol, this.endCol);
      const maxCol = Math.max(this.startCol, this.endCol);
      return row >= minRow && row <= maxRow && col >= minCol && col <= maxCol;
    }
  }
});

在 CSS 中：

.row {
  display: flex;
}

.col {
  width: 50px;
  height: 50px;
  border: 1px solid black;
  text-align: center;
  line-height: 50px;
}

.selected {
  background-color: red;
}