如何在第二个单元格为空的情况下使单元格只读

Question

用户不应该能够在datagridview中的单元格为空的情况下输入数量。

为了说清楚，我想让单元格readonly = true，如果单元列是空的。

colUOM4是列的名称，如果该列的单元格为空，则olNewQty2单元格将为只读的。

我想这个代码，但没有奏效

Public Sub UnitEmpty() 
    For i As Integer = 0 To dgvCount.RowCount - 1 
     If dgvCount.Rows(i).Cells("colUOM4").Value Is Nothing Then 
      MessageBox.Show("Its Worked!") 
      dgvCount.Rows(i).Cells("colNewQty2").ReadOnly = True 
     Else 
      MessageBox.Show("Nothing happened!") 

      Exit For 
     End If 
    Next 
End Sub 

Answer 1

我建议不使用一个循环，因为这将只设置状态，当你执行它并不会响应任何变化。我建议在行和单元级别工作，即当添加一行时设置默认状态，然后在特定单元改变时作出反应，例如，

Private Sub DataGridView1_RowsAdded(sender As Object, e As DataGridViewRowsAddedEventArgs) Handles DataGridView1.RowsAdded 
    For i = e.RowIndex To e.RowIndex + e.RowCount - 1 
     'Make the first cell in each new row read-only by default. 
     DataGridView1(0, i).ReadOnly = True 
    Next 
End Sub 

Private Sub DataGridView1_CellValueChanged(sender As Object, e As DataGridViewCellEventArgs) Handles DataGridView1.CellValueChanged 
    'Check whether the change is in the second column. 
    If e.RowIndex >= 0 AndAlso e.ColumnIndex = 1 Then 
     Dim row = DataGridView1.Rows(e.RowIndex) 

     'Make the first cell in the row read-only if and only if the second cell is empty. 
     row.Cells(0).ReadOnly = (row.Cells(1).Value Is Nothing) 
    End If 
End Sub