Question

如何在asp.net中获取导致PostBack的控件的id。我用

document.getElementById("__EVENTTARGET")

但它仅提供objectHtmlInputElement不是完整的ID。我如何才能在javascript中获取此信息，而不是在后面的代码中。我想在回发后关注那个元素。请帮忙..

Answer 1

您可以使用此blog中提到的此函数来获取回发控件ID，将此ID存储在hiddenfield中并使用JS从隐藏字段中获取该ID

 protected void Page_Load(object sender, EventArgs e)
    {    
        if (Page.IsPostBack)
           HiddenField1.Value = getPostBackControlName();
    } 

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

使用document.getElementById('__EVENTTARGET').value

如何获取控件的id会导致javascript中的回发

2 个答案: