如何获取Dropdownbox C＃ASP.NET的Datasource（）

Question

我有表tblDepartments列DeptID, Department, Description 。 我也有dropdownbox drpDepartments 。 我想在下拉框中显示“ Department ”列的内容。 我尝试对Winforms使用此C＃代码，但没有成功：

        drpDepartments.DataSource = dsDep.Tables["tblDepartment"];
        drpDepartments.DisplayMember = "Department";
        drpDepartments.ValueMember = "DeptID";
        drpDepartments.Text = "Choose Department";

如何使用ASP.NET C＃？ 谢谢。

新代码（仍然无法正常工作）

        sConn = new SqlConnection(sStr);
        daEmp = new SqlDataAdapter("SELECT * FROM tblEmployee", sConn);
        daDep = new SqlDataAdapter("SELECT * FROM tblDepartment", sConn);
        dsEmp = new DataSet();
        dsDep = new DataSet();

        daEmp.Fill(dsEmp, "tblEmployee");
        daDep.Fill(dsDep, "tblDepartment");

        dsEmp.Tables["tblEmployee"].PrimaryKey = new DataColumn[] { dsEmp.Tables["tblEmployee"].Columns["EmployeeID"] };

        DataTable dt=new DataTable();
        daDep.Fill(dt);

        drpDepartments.DataTextField = "Department";
        drpDepartments.DataValueField = "DeptID";
        drpDepartments.DataSource = dt;
        drpDepartments.DataBind();

Answer 1

您必须在asp.net webForms中这样称呼它

        drpDepartments.DataSource = dsDep.Tables["tblDepartment"];// Set DataSource Table First
        drpDepartments.DataTextField = "Department";// Set Column Name of DataTable to set as Text Field
        drpDepartments.DataValueField = "DepartmentID";// Set Column Name of DataTable to set as Value Field
        drpDepartments.DataBind();

您必须using System.Web.UI.WebControls;使用它using System.Web.UI.WebControls; 命名空间。 似乎您正在使用winforms命名空间。

DataTextField等效于DisplayMember而ValueMember等效于DataValueField 。

Answer 2

您是否致电DataBind（）？

drpDepartments.DataSource = dsDep.Tables["tblDepartment"];
drpDepartments.DisplayMember = "Department";
drpDepartments.ValueMember = "DepartmentID";
drpDepartments.Text = "Choose Department";
drpDepartments.DataBind();

Answer 3

drpDepartments.DataSource = ds1;
drpDepartments.DataTextField = "textcol";
drpDepartments.DataValueField = "valuecol";
drpDepartments.DataBind();

在btn_save方法中执行此操作后，添加此。

 cmd.Parameters.AddWithValue("@a", drpDepartments.SelectedValue);

希望能帮助到你。