解决Sortable拖动el-table表头时，由于选择列造成的拖拽顺序错乱的bug

• 原因 由于我的表头是由数组循环遍历生成的，而选择列不在数组内，只能在循环外定义el-table-column，造成拖动时索引错乱
• 错误代码

  <el-table@header-dragend="headerDragend"id="out-table":data="state.sliceTable"borderstriperef="TableRef":row-key="getRowKeys(pageData)"><el-table-column type="selection" width="55" fixed /> 
><template v-for="(item, index) in state.pageDataTitle" :key="index"> <el-table-column:prop="item.value":label="item.name":key="index"><template #default="scope"><slot :name="item.value" :scope="scope">{{ scope.row[item.value] }}</slot></template></el-table-column></template></el-table>

• 解决办法  向数组开头push一条 type="selection" 的对象 并把el-table-column 写到循环体内

  <template v-for="(item, index) in state.pageDataTitle" :key="index"><el-table-column type="selection" v-if="item.type" width="55" fixed /><el-table-column:prop="item.value":label="item.name":key="index"><template #default="scope"><slot :name="item.value" :scope="scope">{{ scope.row[item.value] }}</slot></template></el-table-column></template>

•  当拖动选择列 或 拖向选择列时 仍然会造成拖动顺序混乱 所以我们要禁止掉
• 给el-table-column添加 class-name="allowdrag" 表示除了选择列之外都可以拖动

  <el-table-columnclass-name="allowdrag":label="item.name":key="index"><template #default="scope"><slot :name="item.value" :scope="scope">{{ scope.row[item.value] }}</slot></template></el-table-column>

//拖拽列
const columnDrop2 = (dom) => {if (!dom) returnSortable.create(dom.$el.querySelector('.el-table__header-wrapper>.el-table__header tr'), {handle: '.allowdrag',  //除了选择列都可以选择onEnd: (sortableEvent) => {const targetThElem = sortableEvent.item;const wrapperElem = targetThElem.parentNode;const newIndex = sortableEvent.newIndex;const oldIndex = sortableEvent.oldIndex;const oldTrElement = wrapperElem.children[oldIndex];const currRow = state.pageDataTitle?.splice(oldIndex, 1)[0];state.pageDataTitle?.splice(newIndex, 0, currRow);if (newIndex > oldIndex) {wrapperElem.insertBefore(targetThElem, oldTrElement)} else {wrapperElem.insertBefore(targetThElem,oldTrElement ? oldTrElement.nextElementSibling : oldTrElement)}},})
}

• 这样解决了选择列向其他列拖动 ，但没有解决其他列向选择列拖动 
• 解决办法 添加 :header-cell-class-name="tableRowClassName" 并添加onMove方法

  <el-table:header-cell-class-name="tableRowClassName"id="out-table":data="state.sliceTable"ref="TableRef"><template v-for="(item, index) in state.pageDataTitle" :key="index"><el-table-column type="selection" v-if="item.type" width="55" fixed /><el-table-columnclass-name="allowdrag":prop="item.value":label="item.name":key="index"><template #default="scope"><slot :name="item.value" :scope="scope">{{ scope.row[item.value] }}</slot></template></el-table-column></template></el-table>

//解决向选择列拖动的bugfunction tableRowClassName(row) {if (row.columnIndex == 0) {return "filtered";}return "";}

//拖拽列
const columnDrop2 = (dom) => {if (!dom) returnSortable.create(dom.$el.querySelector('.el-table__header-wrapper>.el-table__header tr'), {handle: '.allowdrag',onEnd: (sortableEvent) => {const targetThElem = sortableEvent.item;const wrapperElem = targetThElem.parentNode;const newIndex = sortableEvent.newIndex;const oldIndex = sortableEvent.oldIndex;const oldTrElement = wrapperElem.children[oldIndex];const currRow = state.pageDataTitle?.splice(oldIndex, 1)[0];state.pageDataTitle?.splice(newIndex, 0, currRow)if (newIndex > oldIndex) {wrapperElem.insertBefore(targetThElem, oldTrElement)} else {wrapperElem.insertBefore(targetThElem,oldTrElement ? oldTrElement.nextElementSibling : oldTrElement)}},//解决向选择列拖动的bugonMove(e) {return e.related.className.indexOf("filtered") === -1;}})
}

完整代码

  <el-table:header-cell-class-name="tableRowClassName"id="out-table":data="state.sliceTable"ref="TableRef"><template v-for="(item, index) in state.pageDataTitle" :key="index"><el-table-column type="selection" v-if="item.type" width="55" fixed /><el-table-columnclass-name="allowdrag":prop="item.value":label="item.name":key="index"><template #default="scope"><slot :name="item.value" :scope="scope">{{ scope.row[item.value] }}</slot></template></el-table-column></template></el-table>

//拖拽列
const columnDrop2 = (dom) => {if (!dom) returnSortable.create(dom.$el.querySelector('.el-table__header-wrapper>.el-table__header tr'), {handle: '.allowdrag',onEnd: (sortableEvent) => {const targetThElem = sortableEvent.item;const wrapperElem = targetThElem.parentNode;const newIndex = sortableEvent.newIndex;const oldIndex = sortableEvent.oldIndex;const oldTrElement = wrapperElem.children[oldIndex];const currRow = state.pageDataTitle?.splice(oldIndex, 1)[0];state.pageDataTitle?.splice(newIndex, 0, currRow)if (newIndex > oldIndex) {wrapperElem.insertBefore(targetThElem, oldTrElement)} else {wrapperElem.insertBefore(targetThElem,oldTrElement ? oldTrElement.nextElementSibling : oldTrElement)}},//解决向选择列拖动的bugonMove(e) {return e.related.className.indexOf("filtered") === -1;}})
}//解决向选择列拖动的bugfunction tableRowClassName(row) {if (row.columnIndex == 0) {return "filtered";}return "";}

效果图