Get all the fields of the tree structure header

Method: get recursively

The following is a screenshot when I wrote the project

    getChildrenIndex(currentColumns) {
      console.log('currentColumns', currentColumns)
      for (var i = 0; i < currentColumns.length; i++) {
        let item = currentColumns[i]
        if (item.children) {
          this.getChildrenIndex(item.children)
        } else {
          this.curColumnList.push(item.dataIndex)
        }
      }
    },

 currentColumns is the tree structure header data

Idea: Clear the array before each recursion, and then push the dataIndex of each recursive item inside, dataIndex is the name of the header field