[align=left]int releId = this.ddlUserType.SelectedIndex;
this.gvUsers.DataSourceID = "odsUserByRoleId";
if (this.gvUsers.Rows.Count == 0)
{
this.gvUsers.DataSourceID = "odsUser";
}[/align]两个不同数据源ID: "odsUser"->查找所有用户; "odsUserByRoleId"->根据用户角色查找用户.
问题: 如果"odsUserByRoleId"数据源查找的结果为空则让它指定所有查找所有用户的数据源, 如何定义IF条件.
这样替换数据源之前,首先要注意写上
this.GridView1.DataSource = null;
确保数据源为空,不然会出错的/DataTable table = new DataTable();
DataTable table1 = new DataTable(); DataColumn c1 = new DataColumn("id1");
table.Columns.Add(c1);
DataColumn c2 = new DataColumn("id2");
table1.Columns.Add(c2);
for (int i = 0; i < 2; i++)
{
DataRow r = table.NewRow();
r[0] = i.ToString();
table.Rows.Add(r);
}
if (table1.Rows.Count == 0)
{
this.GridView1.DataSource = null;
this.GridView1.DataSource = table.DefaultView;
this.GridView1.DataBind();
}
if (table.Rows.Count == 0)
{
this.GridView1.DataSource = null;
this.GridView1.DataSource = table1.DefaultView;
this.GridView1.DataBind();
}