Vb.Net 2013 DataCredView在DirectCast TextBox上的問題

Question

我有此代碼，如果進行了修改（例如第一個單元格），那么我單擊TextBox，然后再次單擊修改后的單元格，以嘗試在同一單元格中再次寫入，這種情況很少見，並且無法正確地寫入同一單元格中。 您需要更改行並返回到上一個單元格以在該單元格中寫回。

我對這種方式的代碼工作很感興趣，但這並沒有產生這種奇怪的效果。

如果我在事件HandleEcTextChanged（...）中刪除了以下代碼

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

該問題不會發生，但是我需要以編程方式更新“長度”列。

另外，如果datagridview連接到數據庫，則會收到錯誤“該數據表的索引已損壞”。

重現此問題的步驟：

1. 修改datagridview“ apple”的第一個單元格。
2. 單擊TexBox“ 0000000”。
3. 單擊上面修改的單元格。
4. 在當前單元格中輸入任何值。
5. 在上一點中，會出現問題。 不要在單元格中正確寫入。

請幫助。

戰車

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

使用直接廣播訪問您的單元。 這是我編寫的用於訪問動態生成的文本框的示例代碼。

    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