我在asp.net中有一个下拉列表当我点击一个选项,我应该得到选定的值,然后将其传递给数据库,然后使用查询结果填充第二个下拉列表。选择选项更改DropdownList C#ASP.NET火灾事件
当我点击第一个下拉菜单时,我似乎无法“触发”此事件。下面是我有:
ASPX代码
<td class="style3">
<asp:DropDownList ID="Currencies" runat="server"
onselectedindexchanged="Currencies_SelectedIndexChanged">
</asp:DropDownList>
</td>
<td>
</td>
</tr>
<tr>
<td class="style2">
Payment Mode</td>
<td class="style3">
<asp:DropDownList ID="PaymentModes" runat="server">
</asp:DropDownList>
</td>
代码隐藏代码C#
String conn = WebConfigurationManager.ConnectionStrings["pvconn"].ToString();
protected void Page_Load(object sender, EventArgs e)
{
populatecurrencylist();
}
public void populatecurrencylist()
{
SqlCommand sql = new SqlCommand("SELECT * FROM CURRENCIES_TBL ORDER BY Currency_Initials",new SqlConnection(conn));
sql.Connection.Open();
SqlDataReader listcurrencies;
listcurrencies = sql.ExecuteReader();
Currencies.DataSource = listcurrencies;
Currencies.DataTextField = "Currency_Initials";
Currencies.DataValueField = "Currency_Group_ID";
Currencies.DataBind();
sql.Connection.Close();
sql.Connection.Dispose();
}
protected void TextBox1_TextChanged(object sender, EventArgs e)
{
}
protected void Currencies_SelectedIndexChanged(object sender, EventArgs e)
{
var currid = Currencies.SelectedValue;
HttpContext.Current.Response.Write(currid);
//int currid = 0;
try
{
SqlCommand sql = new SqlCommand("SELECT * FROM PAYMENT_MODES_TBL WHERE Currency_ID = @currencyid", new SqlConnection(conn));
SqlParameter param0 = new SqlParameter();
param0.ParameterName = "@currencyid";
param0.SqlDbType = System.Data.SqlDbType.Int;
param0.Value = currid;
sql.Parameters.Add(param0);
sql.Connection.Open();
SqlDataReader listpaymodes;
listpaymodes = sql.ExecuteReader();
PaymentModes.DataSource = listpaymodes;
PaymentModes.DataTextField = "Payment_Mode";
PaymentModes.DataValueField = "Paying_Account_Code";
PaymentModes.DataBind();
sql.Connection.Close();
sql.Connection.Dispose();
}
catch(Exception s)
{
HttpContext.Current.Response.Write("Error Occured " + s.Message);
}
}
我可以填充第一个DropDownList没有问题。第二个是似乎没有工作。在ASP.NET中非常新。我来自PHP背景,使用jquery ajax很容易实现,但我想学习C#。
任何帮助表示赞赏。
编辑
所有的答案表明,我让货币下拉列表AutoPostBack = true
我已经做到了:
<asp:DropDownList ID="Currencies" runat="server" AutoPostBack="True"
onselectedindexchanged="Currencies_SelectedIndexChanged">
</asp:DropDownList>
但它似乎仍然没有工作。在附注中,页面重新加载,我的选择菜单选项重置为第一个选项。
将AutoPostBack属性添加为true。 –
更新了我的答案。 –