Question

我在DataGridViewComboBoxColumn中使用DataGridView。我需要的是根据每行 ID 过滤ComboBox值。

Si应该看起来像

-----------------------------
Row ID       ComboBox
              Values
            ID    Name
-----------------------------
1            1     A
             2     B
-----------------------------               
2            3     C
             4     D
-----------------------------

所以我所做的就是创建DataGridViewComboBoxColumn空DataSource之类的它已在下面的代码中显示

var d = new DataGridViewComboBoxColumn()
{
 HeaderText = columnHeader,
 Width = 50,
 DataPropertyName = "D" + i.ToString(),
 DataSource = new BindingSource(){ DataSource = new List<WorkTypeItem>() },
 ValueMember = "ID",
 DisplayMember = "Name",
 Name = "D" + i.ToString()
};
dgvCalendar.Columns.Add(d);

我假设为ComboBox事件中的每个单元格填充行 CellFormatting。

 private void DgvCalendar_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
{

  // Get object bounded with Row  
  CalendarDetailView row = dgvCalendar.Rows[e.RowIndex].DataBoundItem as CalendarDetailView;

  // By row ID  filter list for cell ComboBox
  var workItems = MyWorkItems.Where(x => x.ID == row.ID); 

  // So how we can to populate cell ComboBox now?
  dgvCalendar.Rows[e.RowIndex].Cells[1] ..... ??? = workItems ;


}

我这样做是因为我无法在单元格 ComboBox 中显示所有可能的值，因为它们不适用于每一行。所以这个想法不是显示1000 ComboBox 中的值，但仅包含行ID 引用的值。

我的目标是每个单元格都有自己的值列表，但来自相同的List（）。

有任何线索怎么做？

更新＃1

我只是感谢 Marco Guignard 的代码！我只是为C＃版本更新它。

private void DgvCalendar_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
   if (e.Control is ComboBox)
   {
        int currentKey = (int)dgvCalendar.CurrentRow.Cells[dgvCalendar.CurrentCell.ColumnIndex].Value;

        ComboBox editor = (ComboBox)e.Control;
        CalendarDetailView row = dgvCalendar.CurrentRow.DataBoundItem as CalendarDetailView;

       var filteredItems = WorkTypes.Where(x =>x.ID = row.ID).ToList();

       editor.DataSource = filteredItems;
        editor.SelectedValue = currentKey;
   }           
}

更新＃2

事实上，我已经用类似的方法完成了它，但使用了不同的事件。

因此，最初在列创建逻辑上，我使用数据库表中的所有可能记录来使用值初始化DataGridView，当DataGridView出现时，我们会看到它。

当我们必须编辑组合框单元时，我们只应用对象允许的值列表。

private void DgvCalendar_CellBeginEdit(object sender, DataGridViewCellCancelEventArgs e)
    {
        if (dgvCalendar.Columns[e.ColumnIndex].Name.StartsWith("D"))
        {
           var isComboBox = dgvCalendar.CurrentCell is DataGridViewComboBoxCell;
           if (isComboBox)
           {
               DataGridViewComboBoxCell dgViewComboBoxCell = dgvCalendar.CurrentCell as DataGridViewComboBoxCell;

               CalendarDetailView row = dgvCalendar.Rows[e.RowIndex].DataBoundItem as CalendarDetailView;

               dgViewComboBoxCell.DataSource = new BindingSource()
               {
                 DataSource = row.WorkTypes
               };
          }
      }
    }

Answer 1

您必须处理EditingControlShowing事件。

首先，您必须检查datagridview的CurrentCell列是否与组合框列对应。然后，您可以根据需要更改组合框编辑器数据源。

不要忘记将全局列表保留为列的数据源，因为它仍将用于显示单元格！

以下是VB.NET中的示例（不需要FixupDropDownWidth，它只是更好的UI显示的奖励）。

        Private Sub DataGridView_EditingControlShowing(sender As System.Object, e As System.Windows.Forms.DataGridViewEditingControlShowingEventArgs) Handles DataGridView.EditingControlShowing
                'Route the event depending the cells being edited
                Try
                    If Me.DataGridView.CurrentCell.OwningColumn Is Me.DataGridView.Columns("comboboxcolumnname") Then
                        comboboxcolumnname_EditingControlShowing(sender, e)
                    End If
                Catch ex As Exception
    'Exception handling...
                End Try
            End Sub

    Private Sub comboboxcolumnname_EditingControlShowing(sender As System.Object, e As System.Windows.Forms.DataGridViewEditingControlShowingEventArgs)
        Dim editor As ComboBox = CType(e.Control, ComboBox)
        Dim currentKey As Short = Me.DataGridView.CurrentRow.Cells("comboboxcolumnname").Value

        'Filter editor datasource, remove inactives items except current
        Dim listObject As New List(Of Object)
        listObject.AddRange(GlobalList.Where(Function(c) c.FilterCondition = True OrElse c.ID = currentKey).OrderBy(Function(c) c.Name))
        editor.DataSource = listObject

        editor.SelectedValue = currentKey

        'Adapt the width of the DropDown
        CType(Me.DataGridView.Columns("comboboxcolumnname"), DataGridViewComboBoxColumn).FixupDropDownWidth(listObject)
    End Sub

 <Extension()>
    Public Sub FixupDropDownWidth(column As DataGridViewComboBoxColumn, items As IEnumerable)
        Dim width As Integer = column.DropDownWidth

        Dim vertScrollBarWidth As Integer = 0
        If column.Items.Count > column.MaxDropDownItems Then vertScrollBarWidth = SystemInformation.VerticalScrollBarWidth

        Dim g As Graphics = column.DataGridView.CreateGraphics()
        Dim font As Font

        font = column.DefaultCellStyle.Font
        If font Is Nothing Then font = column.DataGridView.Font

        Dim maxWidth As Integer = 0
        For Each item In items
            Dim stringValue As String
            If item.GetType.GetProperty(column.DisplayMember) IsNot Nothing Then
                stringValue = CStr(item.GetType().GetProperty(column.DisplayMember).GetValue(item, Nothing))
            Else
                stringValue = item.ToString
            End If
            maxWidth = g.MeasureString(CStr(stringValue), font).Width + vertScrollBarWidth
            If width < maxWidth Then width = maxWidth
        Next

        column.DropDownWidth = width
    End Sub

如何根据行ID填充ComboBox DataGridView

1 个答案: