一个奇怪的ADO.net问题!
下面是我的两个按钮控件,当第一次执行时buttonConnectIni_Click_1与buttonRelation_Click都可以成功,但是当我第二次执行buttonRelation_Click的时候,系统就抛出异常 ——“未处理的“System.Data.DuplicateNameException”类型的异常出现在 system.data.dll 中。其他信息: 名为“连接”的关系已经属于此数据集。”这个是什么原因呢?哪为知道是怎么会事情呢?(程序里面其他部分都没有问题)
//关联两个表,在一个dataGrid中显示两个表
private void buttonRelation_Click(object sender, System.EventArgs e)
{
dataSetOne.Clear();
Mcl.DataModules.DMSqlServer MyDMnew2 = new Mcl.DataModules.DMSqlServer();
MyDMnew2.SelectData(dataSetOne,"Select * from Games","Games");
Mcl.DataModules.DMSqlServer MyDMnew1 = new DMSqlServer();
MyDMnew1.SelectData(dataSetOne,"Select * from GameDots","GameDots");
dataColumn1 = dataSetOne.Tables["Games"].Columns["GameID"];
dataColumn2 = dataSetOne.Tables["GameDots"].Columns["GameID"];
dataRelation = new System.Data.DataRelation("连接",dataColumn1,dataColumn2);
dataSetOne.Relations.Add(dataRelation);
DataViewManager DataSetView1 = dataSetOne.DefaultViewManager;
dataGrid1.DataSource = DataSetView1;
dataGrid1.DataMember = "Games";
}
//访问一个表,并在dataGrid1中显示
private void buttonConnectIni_Click_1(object sender, System.EventArgs e)
{
dataSet1.Clear();
Mcl.DataModules.DMSqlServer MyDMnew = new Mcl.DataModules.DMSqlServer();
MyDMnew.SelectData(dataSet1,"Select * from Chat","Chat");
dataGrid1.DataSource = dataSet1.Tables["Chat"].DefaultView;
}