包含 javascript 返回 false 的下拉列表的 Onchange 不会停止调用下拉列表 SelectedIndexChanged答案

【问题标题】：Onchange of dropdownlist containing javascript returning false doesnot stop calling the dropdownlist _SelectedIndexChange包含 javascript 返回 false 的下拉列表的 Onchange 不会停止调用下拉列表 SelectedIndexChanged
【发布时间】：2015-11-06 14:36:16
【问题描述】：

我在转发器中放置了一个下拉列表

<asp:Repeater ID="rptCommissionDistribution" runat="server" OnItemDataBound="rptCommissionDistribution_ItemDataBound"
                OnItemCreated="rptCommissionDistribution_ItemCreated" OnItemCommand="rptCommissionDistribution_ItemCommand">

<asp:DropDownList ID="ddlSplitType" runat="server" DataTextField="SplitTypeName" OnChange="return  confirm_change(this.id,this.value);" DataValueField="SplitTypeId" AutoPostBack="True">
</asp:DropDownList>
<asp:CheckBox ID="chkOverride" runat="server" AutoPostBack="true" OnChange="setdirty();" />
</asp:Repeater>

放置的javascript

<script type="text/javascript">
function confirm_change(id, value) {
    var dropdownid = id;
    var checkboxid = dropdownid.replace("ddlSplitType", "chkOverride");

    if (document.getElementById(checkboxid).checked == true) {          
        alert('clicked');
        return true;
    }
    else {            
        alert('not clicked');
        return false;
    }
}
</script>

在.cs页面上我们有

protected void ddlSplitType_SelectedIndexChanged(object sender, EventArgs e)
 {  
DropDownList ddlSplitType = sender as DropDownList;
RepeaterItem rptCommissionDistributionItem = ddlSplitType.Parent as RepeaterItem;       
CommissionDistributionController objCommissionDistributionController = new CommissionDistributionController();
***-----------And all Stuff--------------***
}

我想要的是当 javascript “返回 false;”比 .cs 页面代码“ddlSplitType_SelectedIndexChanged”不应被调用，并且当 javascript“返回 true;”时那时我的cs页面代码“ddlSplitType_SelectedIndexChanged”应该被调用。

【问题讨论】：

标签： javascript c# jquery asp.net c#-4.0

【解决方案1】：

应该这样做。（由于您的 DDL 在中继器中，因此您必须先找到它）

后面的代码

        protected void Page_Load(object sender, EventArgs e)
        {
             //Only if the event argument was from my drop down add the event
                if (Request.Params["__EVENTARGUMENT"] != null && Request.Params["__EVENTARGUMENT"].Equals("ddlSplitTypechange"))
                    ddlSplitType_SelectedIndexChanged(sender, e);
                if (!Page.IsPostBack)
                {
                    ddlSplitType.Attributes.Add("onchange", "confirm_change();");
            }
        }
        protected void ddlSplitType_SelectedIndexChanged(object sender, EventArgs e)
        {

        }

在你的 JS 中

function confirm_change(id, value) {
    var dropdownid = id;
    var checkboxid = dropdownid.replace("ddlSplitType", "chkOverride");

    if (document.getElementById(checkboxid).checked == true) {          
        alert('clicked');
    __doPostBack("ctl00$MainContent$ddlSplitType","ddlSplitTypechange");
    }
    else {            
        alert('not clicked');
        return false;
    }

    }

你也可以试试这个

     <asp:DropDownList ID="ddlSplitType" runat="server" 
 AutoPostBack="true" onchange="javascript: return confirm_change();" OnSelectedIndexChanged="ddlSplitType_SelectedIndexChanged"></asp:DropDownList>

希望这会有所帮助！

【讨论】：

【解决方案2】：

试试这个：

ASP.NET：

<asp:DropDownList
    ID="ddlTest1"
    runat="server"
    onChange="if (!jsFunction()) return false;"
    OnSelectedIndexChanged="ddlTest1_SelectedIndexChanged"
    AutoPostBack="True">
</asp:DropDownList>

Javascript：

function jsFunction() 
{
    return confirm("Yes or No?");
}

代码隐藏 (C#)：

protected void ddlTest1_SelectedIndexChanged(object sender, EventArgs e)
{
    // Do Something
}

【讨论】：