按钮点击回发后__EVENTTARGET为空

Question

我在aspx页面上有一个按钮

<asp:Button runat="server" CssClass="sc-ButtonHeightWidth" ID="btnFirstSave" Text="Save" OnClick="btnSave_Click" />

我试图在后面的代码中获取事件目标和事件源,以便基于它进行一些验证.我试过下面的代码.

string ctrlname = page.Request.Params.Get("__EVENTTARGET");
string ctrlname = Request.Form["__EVENTTARGET"];
string ctrlname = Request.Params["__EVENTTARGET"];

但以上所有都给了我空洞的价值观.如何获得每次都引起回发的控件.我上面做错了什么？

仅供参考:我已经尝试过本链接中提到的解决方案.但它唯一的返回按钮文本给我.我想要buttonID.

Answer 1

Asp按钮渲染为input类型,submit此方法不会_EVENTTARGET 使用"__doPostBack"方法填充控件,导致回发将添加值,_EVENTTARGET 因此您的按钮ID丢失,_EVENTTARGET您可以遍历页面中的所有控件,以检查哪个控件导致回发.

试试这个来捕捉你的控制 - 在这里

private string getPostBackControlName()
        {
            Control control = null;
            //first we will check the "__EVENTTARGET" because if post back made by       the controls
            //which used "_doPostBack" function also available in Request.Form collection.
            string ctrlname = Page.Request.Params["__EVENTTARGET"];
            if (ctrlname != null && ctrlname != String.Empty)
            {
                control = Page.FindControl(ctrlname);
            }
            // if __EVENTTARGET is null, the control is a button type and we need to
            // iterate over the form collection to find it
            else
            {
                string ctrlStr = String.Empty;
                Control c = null;
                foreach (string ctl in Page.Request.Form)
                {
                    //handle ImageButton they having an additional "quasi-property" in their Id which identifies
                    //mouse x and y coordinates
                    if (ctl.EndsWith(".x") || ctl.EndsWith(".y"))
                    {
                        ctrlStr = ctl.Substring(0, ctl.Length - 2);
                        c = Page.FindControl(ctrlStr);
                    }
                    else
                    {
                        c = Page.FindControl(ctl);
                    }
                    if (c is System.Web.UI.WebControls.Button ||
                             c is System.Web.UI.WebControls.ImageButton)
                    {
                        control = c;
                        break;
                    }
                }
            }
            return control.ID;

        }

Answer 2

到目前为止,我已将usesubmitbehavior设置为false.Damith在评论中给出了一个很好的解决方案.截至目前,它对我来说没有任何问题.了解该物业阅读此链接

希望这会对某人有所帮助.