Question

我正在使用datagridview将Access数据库填充到VB.net中的表单。我想在用户更改行中的值时执行某些操作（验证/更新数据库）。我想等到该行失去焦点以执行更改。我正在使用RowLeave事件来执行任务。问题是当加载datagridview的表单时，它会自动运行RowLeave事件。

如何进行表单加载而不运行RowLeave事件？是什么导致在加载表单时触发RowLeave事件？

编辑：这是我的代码的一部分：

Public Sub loadGradeForm(ByRef temp As Teacher)
    currTeacher = temp
    Me.showGrades() 'Populating the datagridview (GradeGridView)
    Me.Show()
    'After the form loads, it automatically goes to RowLeave when I go through debugging
End Sub

Private Sub showGrades()
    GradeGridView.DataSource = Nothing
    GradeGridView.Rows.Clear()
    GradeGridView.Columns.Clear()

    GradeGridView.AutoGenerateColumns = False
    GradeGridView.AutoSize = True

    GradeGridView.DataSource = currTeacher.ListOfClasses()

    Dim column0 As DataGridViewColumn = New DataGridViewTextBoxColumn()
    column0.DataPropertyName = "Class"
    column0.Name = "Class"
    GradeGridView.Columns.Add(column0)
    Dim column As DataGridViewColumn = New DataGridViewTextBoxColumn()
    column.DataPropertyName = "Grade"
    column.Name = "Grade"
    GradeGridView.Columns.Add(column)
    Dim column1 As DataGridViewColumn = New DataGridViewTextBoxColumn()
    column1.DataPropertyName = "Semester"
    column1.Name = "Semester"
    GradeGridView.Columns.Add(column1)

End Sub

Private Sub GradeGridView_RowLeave(sender As Object, e As DataGridViewCellEventArgs) Handles GradeGridView.RowLeave
    MsgBox(e.RowIndex)
    'This is just a test to see if RowLeave is triggered        
End Sub

Answer 1

当您的DataGridView填充了行时，如果DataGridView失去焦点，则必须以编程方式保留行。

为了避免在表单将行加载到DataGridView时触发代码，我可以想到两个解决方案：

仅在GradeGridView_RowLeave()为Me.IsLoaded的情况下执行True - 方法中的逻辑。
添加您的EventHandler 最初加载数据后，删除GradeGridView_RowLeave(sender As Object, e As DataGridViewCellEventArgs) Handles GradeGridView.RowLeave 并添加一行{{1} } AddHandler GradeGridView.RowLeave, AddressOf GradeGridView_RowLeave - 方法的底部。

当然，只有在程序开始时只加载一次数据时，上述解决方案才有效。如果您需要再次加载数据，就像用户单击更新 -Button一样，我建议您在类中添加showGrades() - 布尔标志，之前将设置为true加载发生，加载完成时为false。在执行LoadingMode的逻辑之前，可以检查此布尔变量，类似于Me.IsLoaded。

加载DataGridView时调用RowLeave事件

1 个答案: