winform中,为combobox添加一个SelectedValueChanged事件后,不论以何种方式关闭窗体均发生有错。
"未将对象引用设置到对象的实例"
下面是事件中的代码:
string usepersonSQL = "select id from depart_use where name = '" + cmb_usecorp.SelectedValue.ToString() + "'";
int depart_useID = DataAccess.ReturnIntData(usepersonSQL);
// TODO: 这行代码将数据加载到表“corpMeasureMSDataSet.depart_use_sub_measure”中。您可以根据需要移动或移除它。
this.depart_use_sub_measureTableAdapter.Connection.ConnectionString = DataAccess.ConnectionString;
this.depart_use_sub_measureTableAdapter.Fill(this.corpMeasureMSDataSet.depart_use_sub_measure, depart_useID); // TODO: 这行代码将数据加载到表“corpMeasureMSDataSet.useperson_measure”中。您可以根据需要移动或移除它。
this.useperson_measureTableAdapter.Connection.ConnectionString = DataAccess.ConnectionString;
this.useperson_measureTableAdapter.Fill(this.corpMeasureMSDataSet.useperson_measure, depart_useID);
不知是何因
"未将对象引用设置到对象的实例"
下面是事件中的代码:
string usepersonSQL = "select id from depart_use where name = '" + cmb_usecorp.SelectedValue.ToString() + "'";
int depart_useID = DataAccess.ReturnIntData(usepersonSQL);
// TODO: 这行代码将数据加载到表“corpMeasureMSDataSet.depart_use_sub_measure”中。您可以根据需要移动或移除它。
this.depart_use_sub_measureTableAdapter.Connection.ConnectionString = DataAccess.ConnectionString;
this.depart_use_sub_measureTableAdapter.Fill(this.corpMeasureMSDataSet.depart_use_sub_measure, depart_useID); // TODO: 这行代码将数据加载到表“corpMeasureMSDataSet.useperson_measure”中。您可以根据需要移动或移除它。
this.useperson_measureTableAdapter.Connection.ConnectionString = DataAccess.ConnectionString;
this.useperson_measureTableAdapter.Fill(this.corpMeasureMSDataSet.useperson_measure, depart_useID);
不知是何因
if (cmb_usecorp.SelectedValue != null)再试试
{
string usepersonSQL = "select id from depart_use where name = '" + cmb_usecorp.SelectedValue.ToString() + "'";
....}