Vb.Net 2013 DataCredView在DirectCast TextBox上的问题

Question

我有此代码，如果进行了修改（例如第一个单元格），那么我单击TextBox，然后再次单击修改后的单元格，以尝试在同一单元格中再次写入，这种情况很少见，并且无法正确地写入同一单元格中。 您需要更改行并返回到上一个单元格以在该单元格中写回。

我对这种方式的代码工作很感兴趣，但这并没有产生这种奇怪的效果。

如果我在事件HandleEcTextChanged（...）中删除了以下代码

Me.grid.Rows（cell.RowIndex）.Cells（Me.lengthColumn.Index）.Value = ec.Text.Length

该问题不会发生，但是我需要以编程方式更新“长度”列。

另外，如果datagridview连接到数据库，则会收到错误“该数据表的索引已损坏”。

重现此问题的步骤：

1. 修改datagridview“ apple”的第一个单元格。
2. 单击TexBox“ 0000000”。
3. 单击上面修改的单元格。
4. 在当前单元格中输入任何值。
5. 在上一点中，会出现问题。 不要在单元格中正确写入。

请帮助。

战车

Public Class TextBoxDirectCast

    Private WithEvents table As DataTable
    Private WithEvents grid As DataGridView
    Private WithEvents textColumn As DataGridViewTextBoxColumn
    Private WithEvents lengthColumn As DataGridViewTextBoxColumn
    Private WithEvents texboxtext As TextBox

    Public Sub New()
        Me.InitializeComponent()
        Me.ClientSize = New Size(400, 300)
        Me.table = New DataTable()
        Me.table.Columns.Add("Text", GetType(String))
        Me.table.Columns.Add("Length", GetType(Integer))
        Me.table.Rows.Add("apple", 5)
        Me.table.Rows.Add("banana", 6)
        Me.table.Rows.Add("orange", 6)
        Me.textColumn = New DataGridViewTextBoxColumn() With {.DataPropertyName = "Text", .HeaderText = "Text", .AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill}
        Me.lengthColumn = New DataGridViewTextBoxColumn() With {.DataPropertyName = "Length", .ReadOnly = True, .HeaderText = "Length (Computed)", .Width = 200, .MinimumWidth = 200}
        Me.grid = New DataGridView() With {.Dock = DockStyle.Top, .AutoGenerateColumns = False, .DataSource = Me.table, .TabIndex = 0}
        Me.grid.Columns.AddRange({Me.textColumn, Me.lengthColumn})
        Me.Controls.Add(Me.grid)
        Me.texboxtext = New TextBox With {.Anchor = AnchorStyles.Bottom Or AnchorStyles.Left, .Text = "0000000", .Location = New Point(10, Me.ClientSize.Height - 30), .TabIndex = 1}
        Me.Controls.Add(Me.texboxtext)
        Me.texboxtext.BringToFront()
    End Sub

    Private Sub HandleEcShowing(sender As Object, e As DataGridViewEditingControlShowingEventArgs) Handles grid.EditingControlShowing
        If (Me.grid.CurrentCell.ColumnIndex = Me.textColumn.Index) Then
            Dim ec As DataGridViewTextBoxEditingControl = DirectCast(e.Control, DataGridViewTextBoxEditingControl)
            Me.UnhookEc(ec) 'Important: Remove handles to avoid recursion.
            Me.HookEc(ec)
        End If
    End Sub

    Private Sub HandleEcTextChanged(sender As Object, e As EventArgs)
        Dim ec As DataGridViewTextBoxEditingControl = DirectCast(sender, DataGridViewTextBoxEditingControl)
        Dim cell As DataGridViewTextBoxCell = DirectCast(Me.grid.CurrentCell, DataGridViewTextBoxCell)
        Me.grid.Rows(cell.RowIndex).Cells(Me.lengthColumn.Index).Value = ec.Text.Length
    End Sub

    Private Sub HandleEcDisposed(sender As Object, e As EventArgs)
        Me.UnhookEc(TryCast(sender, DataGridViewTextBoxEditingControl)) 'Important: This will ensure removal of the hooked handles.
    End Sub

    Private Sub HookEc(ec As DataGridViewTextBoxEditingControl)
        If (Not ec Is Nothing) Then
            AddHandler ec.TextChanged, AddressOf Me.HandleEcTextChanged
            AddHandler ec.Disposed, AddressOf Me.HandleEcDisposed
        End If
    End Sub

    Private Sub UnhookEc(ec As DataGridViewTextBoxEditingControl)
        If (Not ec Is Nothing) Then
            RemoveHandler ec.TextChanged, AddressOf Me.HandleEcTextChanged
            RemoveHandler ec.Disposed, AddressOf Me.HandleEcDisposed
        End If
    End Sub

End Class

Answer 1

使用直接广播访问您的单元。 这是我编写的用于访问动态生成的文本框的示例代码。

    Dim txt = New TextBox()
    txt.Name = "name1"
    txt.Size = New Size(200, 70)
    txt.Location = New Point(40, 40)
    txt.Text = "I am a new textbox"
    Me.Controls.Add(txt)
    DirectCast(Me.Controls("name1"), TextBox).Text = "Some stuff here" 'The magic happens here