如何將文本框綁定到下拉列表？

Question

我有一個允許用戶選擇SupplierName的下拉列表。有效。 的問題是，我需要的文本框填充以對應SupplierEmail：

protected void ddl1_SelectedIndexChanged(object sender, EventArgs e) 
{ 
    // FetchData(); 
    DataTable dt = new DataTable(); 
    con.Open(); 

    SqlCommand cmd1 = new SqlCommand("ePMT_SP_BindSupplierDDLToTextBox", con); 
    cmd1.Parameters.Add(new SqlParameter("@SupplierEmail",ddlSupplier.SelectedItem));    
    // txtSupplierEmail.Text = dt.Rows[0]["SupplierEmail"].ToString(); 
    // SqlDataReader datareader = cmd.ExecuteReader();     
    foreach (DataRow row in dt.Rows) 
    { 
     txtSupplierEmail.Text = row["SupplierEmail"].ToString(); 
    } 
} 

的存儲過程ePMT_SP_BindSupplierDDLToTextBox：

SELECT SupplierEmail 
FROM dbo.EPMT_MASTER_SUPPLIER 
WHERE SupplierName = @SupplierName 

的存儲過程ePMT_SP_BindSupplier：

SELECT SupplierName 
FROM SSMC_EPMT.dbo.EPMT_MASTER_SUPPLIER 

private void BindDropdownlist() 
{ 
    DataTable dtSupplier = eBiz.BindSupplier(); 
    ddlSupplier.DataSource = dtSupplier; 
    ddlSupplier.DataTextField = "SupplierName"; 
    ddlSupplier.DataValueField = "SupplierName"; 
    ddlSupplier.DataBind(); 
    ddlSupplier.Items.Insert(0, new ListItem("--Select--", "0")); 
} 

<label class="col-md-4 control-label" for="inputRefNo"> 
    Vendor :<span style="color: red">*</span> 
</label> 
<div class="input-group col-md-8"> 
    <asp:DropDownList ID="ddlSupplier" OnSelectedIndexChanged="ddl1_SelectedIndexChanged" runat="server" CssClass="form-control" AutoPostBack="true"></asp:DropDownList> 
</div> 

Answer 1

嘗試這個;

con.Open(); 
SqlCommand cmd1 = new SqlCommand("ePMT_SP_BindSupplierDDLToTextBox", con); 
cmd1.Parameters.Add(new SqlParameter("@SupplierEmail",ddlSupplier.SelectedItem)); 
SqlDataReader datareader = cmd.ExecuteReader(); 
while(datareader.Read()) 
{ 
    txtSupplierEmail.Text = datareader["SupplierEmail"].ToString(); 
} 

Answer 2

我找到了解決方案。

我要創建另一個存儲過程，然後將其連接到下拉列表名稱：

String sql = "SELECT * from dbo.EPMT_MASTER_SUPPLIER where SUPPLIERName = '" + ddlSupplier.SelectedItem.Text + "' "; 

抽出的一切，我想彈出數據的文字框。