通过

行错误信息

为了避免在编辑值 DataTable时对行错误做出响应，可以将错误信息添加到该行供以后使用。 该 DataRow 对象在每一行上提供一个 RowError 属性以实现此目的。 将数据添加到 DataRow 的 RowError 属性会将 HasErrorsDataRow 的属性设置为 true。 如果 DataRow 是 DataTable 的一部分，并且 DataRow.HasErrors 为 true， 则 DataTable.HasErrors 属性也 为 true。 这也适用于 DataTable 所属的数据集。 测试错误时，可以检查 HasErrors 属性以确定是否已将错误信息添加到任何行。 如果 HasErrors 为 true，则可以使用 GetErrorsDataTable 的方法返回并仅检查出现错误的行，如以下示例所示。

Dim workTable As DataTable = New DataTable("Customers")  
workTable.Columns.Add("CustID", Type.GetType("System.Int32"))  
workTable.Columns.Add("Total", Type.GetType("System.Double"))  
  
AddHandler workTable.RowChanged, New DataRowChangeEventHandler(AddressOf OnRowChanged)  
  
Dim i  As Int32  
  
For i  = 0 To 10  
  workTable.Rows.Add(New Object() {i , i *100})  
Next  
  
If workTable.HasErrors Then  
  Console.WriteLine("Errors in Table " & workTable.TableName)  
  
  Dim myRow As DataRow  
  
  For Each myRow In workTable.GetErrors()  
    Console.WriteLine("CustID = " & myRow("CustID").ToString())  
    Console.WriteLine(" Error = " & myRow.RowError & vbCrLf)  
  Next  
End If  
  
Private Shared Sub OnRowChanged( _  
    sender As Object, args As DataRowChangeEventArgs)  
  ' Check for zero values.  
  If CDbl(args.Row("Total")) = 0 Then args.Row.RowError = _  
      "Total cannot be 0."  
End Sub  

DataTable  workTable = new DataTable("Customers");  
workTable.Columns.Add("CustID", typeof(Int32));  
workTable.Columns.Add("Total", typeof(Double));  
  
workTable.RowChanged += new DataRowChangeEventHandler(OnRowChanged);  
  
for (int i = 0; i < 10; i++)  
  workTable.Rows.Add(new Object[] {i, i*100});  
  
if (workTable.HasErrors)  
{  
  Console.WriteLine("Errors in Table " + workTable.TableName);  
  
  foreach (DataRow myRow in workTable.GetErrors())  
  {  
    Console.WriteLine("CustID = " + myRow["CustID"]);  
    Console.WriteLine(" Error = " + myRow.RowError + "\n");  
  }  
}  
  
protected static void OnRowChanged(  
    Object sender, DataRowChangeEventArgs args)  
{  
  // Check for zero values.  
  if (args.Row["Total"].Equals(0D))  
    args.Row.RowError = "Total cannot be 0.";  
}

另请参阅