如何在绑定到链接到 EF4 实体的绑定源时对 DataGridView 进行排序 [英] How to sort DataGridView when bound to a binding source that is linked to an EF4 Entity

问题描述

我有一个 DataGridView 链接到一个 BindingSource.

I have a DataGridView that is linked to a BindingSource.

我的 BindingSource 链接到一个 IQueryable 实体列表:

My BindingSource is linked to an IQueryable list of entities:

    public void BindTo(IQueryable elements)
    {
        BindingSource source = new BindingSource();
        source.DataSource = elements;

        bindingNavigator1.BindingSource = source;
        dataGridView1.DataSource = source;

    }

我希望我的用户能够点击网格标题来对数据进行排序 - 努力让它发挥作用.是否可以?如果是这样，我该怎么做?

I am wanting my users to be able to click on the grid headers to sort the data - struggling to get this to work. Is it possible? If so, how do I do it?

推荐答案

我最近也遇到了同样的问题；似乎 IQueryable 接口没有为 DataViewGrid 提供足够的信息来了解如何自动对数据进行排序；所以你必须使用它可以使用的东西从实体源重新打包你的集合，或者做我所做的并手动处理排序功能:

I recently struggled with this same issue; it seems that the IQueryable interface doesn't provide enough information for the DataViewGrid to know how to sort the data automatically; so you have to either repackage your collection from the Entity source using something it can use or do what I did and handle the sorting functionality manually:

      private void myDataGridView_ColumnHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e)
  {
     DataGridViewColumn column = myDataGridView.Columns[e.ColumnIndex];

     _isSortAscending = (_sortColumn == null || _isSortAscending == false);

     string direction = _isSortAscending ? "ASC" : "DESC";

     myBindingSource.DataSource = _context.MyEntities.OrderBy(
        string.Format("it.{0} {1}", column.DataPropertyName, direction)).ToList();

     if (_sortColumn != null) _sortColumn.HeaderCell.SortGlyphDirection = SortOrder.None;
     column.HeaderCell.SortGlyphDirection = _isSortAscending ? SortOrder.Ascending : SortOrder.Descending;
     _sortColumn = column;
  }

希望能帮到你.

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