使用JavaScript的下拉列表 [英] Dropdownlist with javascript

问题描述

在我的Web应用程序中，我有一个下拉列表，其中填充了
中的一些值 数据库.我想如果某个人没有从dropdownlist中选择任何值，然后单击Submit按钮，它必须显示警报信息，例如您必须从dropdownlist中选择值"
当用户没有从按钮单击事件处理程序的下拉列表中选择值作为流时，我很累于添加conditionblock:

Hi,
In my web application i have a dropdownlist which get populated by some values from
database. I want if some one have not select any value from dropdownlist and click submit button the it must show alert messege like "you must select value from dropdownlist"
I tired to add conditionblock when user doesnot select values from dropdownlist in button click eventHandler as flows:

System.Text.StringBuilder sbMessage = new StringBuilder();
                sbMessage.Append("<script type=\"text/javascript\">");
                sbMessage.Append("function alertMessage() {");
                sbMessage.Append("alert(\"please select value from dropdownlist\");");
                sbMessage.Append("}");
                sbMessage.Append("</script>");
                this.Page.RegisterClientScriptBlock("alerMessege", sbMessage.ToString());

但这不会显示警报消息，任何人都可以在这里帮助我.

but this doesnt show alert message can any one help me out here.

推荐答案

我认为应该是

I think it should be

this.Page.RegisterClientScriptBlock(this.GetType(), "alertMessage", sbMessage.ToString());

您的代码(alerMessege)中存在拼写错误.

There is spelling mistake in your code (alerMessege).

在提交按钮客户端单击时调用onButtonClick函数-

call onButtonClick function on submit button client click--

<script>
function onButtonClick()
{
dropdown=document.getElementById("<%=ddlSelect.ClientID %>")
if(dropdown.selectedIndex<0)
{
alert("Your msg");
return false;
}
return true;

}
</script>

--Pankaj

--Pankaj

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