我怎样才能避免在每个选定的下拉列表中编写代码 [英] how can i avoid writing code on every dropdown selectedindexchanged

问题描述

SqlDataAdapter da4 = new SqlDataAdapter("select * from vehicle_category where vehicle_name='" + ddlvnameri.SelectedItem.ToString() + "' ", con);
DataTable dt4 = new DataTable();
da4.Fill(dt4);
if (ddlvtype.SelectedItem.ToString() == "AC" && ddlrate.SelectedItem.ToString() == "Rate/km")
{
    txtrate.Text = dt4.Rows[0]["ac_rate_km"].ToString();
}
else if (ddlvtype.SelectedItem.ToString() == "Non-AC" && ddlrate.SelectedItem.ToString() == "Rate/km")
{
    txtrate.Text = dt4.Rows[0]["rate_km"].ToString();
}
else if (ddlvtype.SelectedItem.ToString() == "AC" && ddlrate.SelectedItem.ToString() == "Rate/day")
{
    txtrate.Text = dt4.Rows[0]["ac_rate_day"].ToString();
}
else
{
    txtrate.Text = dt4.Rows[0]["rate_day"].ToString();
}

此代码我必须在每个ddl_selectedindexchanged和我必须使用这一堆下拉列表10次我怎样才能减少dis



代码块添加 - OriginalGriff [/ edit]

this code i have to write on every ddl_selectedindexchanged and i have to use this bunch of dropdown list 10 times how can i reduce dis

[edit]Code block added - OriginalGriff[/edit]

推荐答案

我假设您的意思是您有10个下拉列表，并且您需要的代码不同之处仅在于它们用作SQL语句源的控件？如果是这样，那么这很简单：只需将所有下拉列表发送到同一个通风处理程序并使用 sender 参数来确定它是哪个控件：

I assume you mean that you have 10 drop down lists and you need code which differs only in which control they use as the source for the SQL statement? If so, then it is pretty easy: just send all teh drop down lists to the same vent handler and use the sender parameter to determine which control it is:

DropDownList ddl = sender as DropDownList;
if (ddl != null)
   {
   SqlDataAdapter da4 = new SqlDataAdapter("select * from vehicle_category where vehicle_name='" + ddl.SelectedItem.ToString() + "' ", con);
   ...

如果这不是你的问题，那么你需要更详细地解释一下你是什么遇到问题。

If that isn''t your problem, then you need to explain in more detail what you are having problems with.

你好，



您可以在具有以下签名的函数中转换代码并将其附加到每个下拉列表控件在您的页面中通过 OnSelectedIndexChanged 。参数sender可以帮助您确定哪个控件引发了事件。

Hello,

You can turn your code in a function with following signature and attach it every dropdownlist control in your page via OnSelectedIndexChanged. The parameter sender should help you in determining which control has raised the event.

void ddlSelectedIndexChanged(object sender, System.EventArgs e)

问候，

Regards,

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