Question

我在使用SQL语句时遇到问题，无法将我的dropdownlist select中的值传递给gridview。我测试了我的SQL语句Serve Management Studio，具有特定的日期，并且它可以工作，但它不能使用我的Dropdownlist中的select值。我如何将值传递给Gridview？谢谢你的帮助，我是asp.net世界的新生。

网络应用程序的图像：我的数据库图片：

public void RefreshDay()
        {
            SqlConnection conn = new SqlConnection(@"data source =.\sqlexpress; integrated security = true; database = DBdentist");
            SqlDataAdapter da = null;
            DataSet ds = null;
            DataTable dt = null;
            string sqlsel = "SELECT Distinct patient.patientID, day from patient, patientreservation where patient.patientID = patientreservation.patientID";


        try
        {

            da = new SqlDataAdapter();  
            da.SelectCommand = new SqlCommand(sqlsel, conn);  
            ds = new DataSet();
            da.Fill(ds, "myDay");   
            dt = ds.Tables["myDay"];   


            DropDownListDay.DataSource = dt;
            DropDownListDay.DataTextField = "day";
            DropDownListDay.DataValueField = "patientID";
            DropDownListDay.DataBind();
            DropDownListDay.Items.Insert(0, "Select Day"); 
        }
        catch (Exception ex)
        {
            LabelDay.Text = ex.Message; 
        }
        finally
        {
            conn.Close(); 
        }

    }



    protected void DropDownListDay_SelectedIndexChanged(object sender, EventArgs e)
    {
        if (DropDownListDay.SelectedIndex != 0)
        {
            SqlConnection conn = new SqlConnection(@"data source =.\sqlexpress; integrated security = true; database = DbDentist");
            SqlDataAdapter da = null;
            DataSet ds = null;
            DataTable dt = null;
            string sqlsel = "SELECT patientreservation.patientID, patient.firstname, patient.lastname, patientreservation.day, patientreservation.hour, treatment.treatment FROM((patientreservation INNER JOIN patient ON patientreservation.patientID = patient.patientID) INNER JOIN treatment ON patientreservation.treatmentID = treatment.treatmentID) WHERE patientreservation.day = " + DropDownListDay.SelectedValue + "";

            try
            {

                da = new SqlDataAdapter();  
                da.SelectCommand = new SqlCommand(sqlsel, conn); 
                ds = new DataSet();
                da.Fill(ds, "myDay");  
                dt = ds.Tables["myDay"];
                GridViewDay.DataSource = dt; 
                GridViewDay.DataBind();

            }
            catch (Exception ex)
            {
                LabelDay.Text = ex.Message; 
            }
            finally
            {
                conn.Close(); 
            }

        }

        else
        {
            LabelDay.Text = "You choose None:";
        }
    }
}

}

Answer 1

您的下拉列表的配置是

DropDownListDay.DataTextField = "day";
DropDownListDay.DataValueField = "day";

SELECT patientreservation.patientID, patient.firstname, patient.lastname, patientreservation.day, patientreservation.hour, treatment.treatment FROM((patientreservation INNER JOIN patient ON patientreservation.patientID = patient.patientID) INNER JOIN treatment ON patientreservation.treatmentID = treatment.treatmentID) WHERE **patientreservation.day** = " + DropDownListDay.**SelectedValue** + "";

但是如果要使用当前选定的值进行过滤，则需要天作为值

WHERE **patientreservation.day** = " + DropDownListDay.**SelectedText** + "";

或者您可以尝试使用<DataGrid x:Name="dg"> <DataGrid.CellStyle> <Style TargetType="DataGridCell"> <Style.Triggers> <DataTrigger Binding="{Binding Place}" Value="true"> <Setter Property="Background" Value="Yellow"/> </DataTrigger> </Style.Triggers> </Style> </DataGrid.CellStyle> </DataGrid>

Answer 2

你可以简单地使用它：

WHERE patientreservation.day = '" + DropDownListDay.Text.ToString() + "'";

Answer 3

感谢您的帮助。我尝试了一切

DropDownListDay.DataTextField = "day"; DropDownListDay.DataValueField = "day"

帮助。我的gridview也遇到了一些问题。我加上删除它并制作一个新的，不知怎的帮助。

Answer 4

下拉列表未触发此事件。尝试将此AutoPostBack =“true”放在asp下拉列表标记中。

如何从Dropdownlist中选择一个值并将值传递给Gridview？

4 个答案: