database - 从数据库中删除错误

Question

我有一个通过 VS 2010(本地数据库文件选项)创建的 SQL Server Compact 数据库。在表单加载 (CategoryForm) 时，我将数据库中的值加载到 DataGridView1 中。我还以编程方式添加了一个额外的 ButtonColumn，用于 Delete 部分。问题是这样的:

• 在初始表单加载时，我第一次在任何行上按删除键时，它起作用了。如果我再按一次，它就不起作用。
• 我第二次单击按钮时，我在 Msgbox 上打印的文本是按钮的文本! (删除)(包括屏幕截图)p.s 如下所述，当我注释掉多余的内容时，我得到了返回的正确值。

我尝试过的:

• 注释掉所有与 SQL 相关的内容，只留下我获取 RowIndex 的部分以及该索引处特定单元格的值。我将它们都打印在 MsgBox 上。我得到的值是正确的。例如，0 索引和值 test 为带有文本 test 的第一行。

下面是我的进度和截图:

CellContentClick 方法:

Private Sub DataGridView1_CellContectClick(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellContentClick

    Dim i As String

    'If e.ColumnIndex = 1 Then
    'If e.RowIndex >= 0 And e.RowIndex <= DataGridView1.Rows.Count - 1 Then

    i = DataGridView1.Rows(e.RowIndex).Cells(0).Value.ToString
    MsgBox(e.RowIndex)
    MsgBox(i)
    SQLStringDelete = "DELETE FROM Category WHERE categoryname = '" & i & "'"
    SQLConn.ConnectionString = ConnString 'Set the Connection String
    SQLConn.Open() 'Open the connection
    SQLCmd.Connection = SQLConn 'Sets the Connection to use with the SQL Command
    SQLCmd.CommandText = SQLStringDelete 'Sets the SQL String
    SQLCmd.ExecuteNonQuery() 'Executes SQL Command

    'Create Adapter
    Dim DataAdapter As SqlCeDataAdapter = New SqlCeDataAdapter("SELECT categoryname FROM Category", SQLConn)
    'Create DataSet
    Dim Dataset As New DataSet
    'fill the datset
    DataAdapter.Fill(Dataset)
    'attach dataset to the datagrid
    With DataGridView1
        .DataSource = Dataset.Tables(0)
        .Columns(0).HeaderText = ""
        .Columns(0).AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill
    End With

    DataAdapter = Nothing
    Dataset = Nothing

    SQLConn.Close() 'Close the connection



End Sub

Form_Load 方法:

 Private Sub CategoryForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        SQLConn.ConnectionString = ConnString 'Set the Connection String
        SQLConn.Open() 'Open the connection

        'Create Adapter
        Dim DataAdapter As SqlCeDataAdapter = New SqlCeDataAdapter("SELECT categoryname FROM Category", SQLConn)
        'Create DataSet
        Dim Dataset As New DataSet
        'fill the datset
        DataAdapter.Fill(Dataset)
        'attach dataset to the datagrid
        With DataGridView1
            .DataSource = Dataset.Tables(0)
            .Columns(0).HeaderText = ""
            .Columns(0).AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill
        End With

        DataAdapter = Nothing
        Dataset = Nothing
        SQLConn.Close()

        With buttonColumn
            .Name = "DeleteButtonColumn"
            .HeaderText = ""
            .Text = "Delete"
            .UseColumnTextForButtonValue = True
            .AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill
            .Width = 50
        End With

        If DataGridView1.Columns.Count = 1 Then
            DataGridView1.Columns.Add(buttonColumn)
        End If

    End Sub

截图:

Answer 1

事实证明，自动重新生成的列在每次第二次单击时都会导致列重新排列。只需在表单加载和事件中设置 DataGridView1.AutoGenerateColumns = false 即可。