在Flutter DataTable中对列值进行排序 [英] Sorting Column Values in Flutter DataTable

问题描述

我很难对DataTable中的列进行排序.

I am having serious difficulty in sorting columns in my DataTable.

这是我的代码

  SingleChildScrollView(
  scrollDirection: Axis.horizontal,
  child: DataTable(
    sortColumnIndex: 0,
    sortAscending: true,

    columnSpacing: 5.0,
      horizontalMargin: 10,
    columns: [
      DataColumn(label: Text('Col1'),          
      DataColumn(label: Text('Col2'),numeric: false ),
      DataColumn(label: Text('Col3'),numeric: true ),
      DataColumn(label: Text('Col4'), numeric: true),
      DataColumn(label: Text('Col5'), numeric: true),
    ],
    rows: myList
        .map(
        ((element) => DataRow(
          cells: <DataCell>[
            DataCell(Text(element["Col1"]), placeholder: true,showEditIcon: false),
            DataCell(Text(element["Col2"].toString())),
            DataCell(Text(element["Col3"].toString())),
            DataCell(Text(element["Col4"].toString())),
            DataCell(Text(element["Col5"].toString())),
          ],
        )),
    ).toList(),
  ),
));

我还要做什么?理想情况下，我希望在用户按下的任何列上都具有排序功能，但就目前而言，我很高兴只有1列可以进行排序.

What more am I meant to do? Ideally, I'd like to have the sort function on whichever column the user presses on, but for now, I'd be delighted with just 1 column working being sortable.

如您所见，我添加了约束:

As you can see, I have added the constraints:

    sortColumnIndex: 0,
    sortAscending: true,

但是我所得到的只是第一列附近的箭头(ColumnIndex = 0)-当您按下它时，它实际上什么也没做.

But all I get is an arrow near 1st column (ColumnIndex = 0) - which really does nothing when you press it.

我做错了什么?

推荐答案

您必须在要排序的列中添加"onSort:"，然后调用排序功能.

You have to add a 'onSort: ,' to the column that will be sorted, and call a sorting function.

bool sort;

DataTable(
        sortAscending: sort,
        sortColumnIndex: 0,
        columns: [
          DataColumn(
              label: Text("Col1"),
              onSort: (columnIndex, ascending) {
                setState(() {
                  sort = !sort;
                });
                onSortColum(columnIndex, ascending);
              }),
...

和onSortColum函数:

And the onSortColum function:

onSortColum(int columnIndex, bool ascending) {
    if (columnIndex == 0) {
      if (ascending) {
        yourDataList.sort((a, b) => a['name'].compareTo(b['name']));
      } else {
        yourDataList.sort((a, b) => b['name'].compareTo(a['name']));
      }
    }
  }

希望有帮助！

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