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我正在尝试根据 ToolStripComboBox 中的选择填充 TableAdapter。首先，我想通过将 ToolStipComboBox 绑定到数据源来填充它。然后一旦它被填充，我想填充 TableAdapter。

这是我的代码：

Private Sub ToolStripComboBox_MessageType_Click(sender As Object, e As EventArgs) Handles ToolStripComboBox_MessageType.Click
    Me.ToolStripComboBox_MessageType.ComboBox.DataSource = DataSet_UToolDb.XML_MESSAGE_TYPE
    Me.ToolStripComboBox_MessageType.ComboBox.DisplayMember = "MessageType"
    Me.ToolStripComboBox_MessageType.ComboBox.ValueMember = "MTId"
End Sub

Private Sub ToolStripComboBox_MessageType_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ToolStripComboBox_MessageType.SelectedIndexChanged
    Me.TableAdapter_XML_MESSAGE_STRUCTURE.Fill(DataSet_UToolDb.XML_MESSAGE_STRUCTURE, Me.ToolStripComboBox_MessageType.ComboBox.SelectedValue)
End Sub

出于某种原因（如果我单步执行我的代码），代码会从设置数据源的位置跳转到填充 TableAdapter 的位置。这会导致异常，因为 TableAdapter 的选择查询正在根据从 ToolStipComboBox 中选择的值查找值。

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1 回答 1

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我怀疑您的代码正在跳转到填充 TableAdapter 的位置，因为通过设置 ComboBox 的 DataSource 会导致SelectedIndexChanged事件被触发。

SelectedIndexChanged因此，如果ToolStripComboBox 尚未填充，您需要告诉处理程序返回，您可以通过在填充 ToolStripComboBox 时设置布尔标志来完成。例如：

Dim m_ToolStripComboBoxPopulated As Boolean

Private Sub ToolStripComboBox_MessageType_Click(sender As Object, e As EventArgs) Handles ToolStripComboBox_MessageType.Click
    Me.m_ToolStripComboBoxPopulated = False
    Me.ToolStripComboBox_MessageType.ComboBox.DataSource = DataSet_UToolDb.XML_MESSAGE_TYPE
    Me.ToolStripComboBox_MessageType.ComboBox.DisplayMember = "MessageType"
    Me.ToolStripComboBox_MessageType.ComboBox.ValueMember = "MTId"
    ' Indicate ToolStripComboBox has been populated
    Me.m_ToolStripComboBoxPopulated = True
End Sub

Private Sub ToolStripComboBox_MessageType_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ToolStripComboBox_MessageType.SelectedIndexChanged
    If (Me.m_ToolStripComboBoxPopulated = False) Then
        Return
    End If
    Me.TableAdapter_XML_MESSAGE_STRUCTURE.Fill(DataSet_UToolDb.XML_MESSAGE_STRUCTURE, Me.ToolStripComboBox_MessageType.ComboBox.SelectedValue)
End Sub
于 2013-12-18T10:11:20.317 回答