LISTBOX 娶不到焦点怎么回事 在线等下 asp.net listbox question！！

Question

  var StudentSGUID = $("ListBoxStudent").value;
     var StudentIndex = $("ListBoxStudent").selectedIndex;
     var SubjectIndex = $("ListBoxSubject").selectedIndex;
     Callback1.Callback(StudentSGUID,StudentIndex,SubjectIndex);
    
    if (SubjectIndex != $("ListBoxSubject").length - 1)
    {
        $("ListBoxSubject").selectedIndex = eval(SubjectIndex) + 1 ;
        //$("ListBoxSubject").focus();
        document.getElementById("ListBoxSubject").focus();
    }
    else
    {
        $("ListBoxStudent").selectedIndex = eval(StudentIndex) + 1;
        //$("ListBoxStudent").focus();
          document.getElementById("ListBoxStudent").focus();
     }

Answer 1

$("ListBoxStudent")你这个取得到值吗？
一般都是用$("#ListBoxStudent")取值把

Answer 2

SetFocus 只能在 PreRender 之前和之中调用 调用focus时出现这个上述错误  == ！

Answer 3

 protected void Button1_ServerClick(object sender, EventArgs e)
    {
        string lpSGUID = this.TextBoxSGUID.Value;
        string sImageURL = Server.MapPath("~/Temp/" + lpSGUID + ".JPG");
        File.Delete(sImageURL);
        if (this.FileUpload1.FileName != "")
        {
            try
            {
                this.FileUpload1.SaveAs(sImageURL);
                this.Image1.ImageUrl = "~/Temp/" + lpSGUID + ".JPG";
                this.ImageURL.Value = sImageURL;
            }
            catch
            {
                Page.ClientScript.RegisterStartupScript(this.GetType(), "Cscript", "<script for=window event=onload>window.alert('图片文件上传失败！');</script>");
                return;
            }
        }
        else
        {
            Page.ClientScript.RegisterStartupScript(this.GetType(), "Cscript", "<script for=window event=onload>window.alert('请先选择图片文件！');</script>");
            return;
        }
    }      
图片怎么查看不出来 求高手！！！

Answer 4

var myObject=document.getElementById("<%= ListBoxStudent.ClientID %>");//取得Web控件

Answer 5

this.Image1.ImageUrl = "~/Temp/" + lpSGUID + ".JPG";
换成
this.Image1.ImageUrl = sImageURL;

Answer 6

#likevs# 灰常感谢你 图片显示问题搞定

Answer 7

var myObject=document.getElementById("<%= ListBoxStudent.ClientID %>");//取得Web控件
我这样取值 
 var StudentSGUID = $("ListBoxStudent").value;
     var StudentIndex = $("ListBoxStudent").selectedIndex;     var SubjectIndex = $("ListBoxSubject").selectedIndex;
//     var StudentIndex=document.getElementById("<%= ListBoxStudent.ClientID %>").selectedIndex;//
//     alert(StudentIndex);
//     var SubjectIndex=document.getElementById("<%= ListBoxSubject.ClientID %>").selectedIndex;//
    
    
    if (SubjectIndex != $("ListBoxSubject").length -1 )
    {      
        //$("ListBoxSubject").focus();
        document.getElementById("<%= ListBoxStudent.ClientID %>").focus();
        $("ListBoxSubject").selectedIndex = eval(SubjectIndex) + 1 ;
    }
    else
    {
        //$("ListBoxStudent").focus();
        document.getElementById("<%= ListBoxStudent.ClientID %>").focus();
        $("ListBoxStudent").selectedIndex = eval(StudentIndex) + 1;
        //$("ListBoxSubject").selectedIndex = 0;
     }
     
      Callback1.Callback(StudentSGUID,StudentIndex,SubjectIndex);

Answer 8

取得Web控件 统一用这种方法吗

Answer 9

是的，因为Web控件在生成时，会按一定算法生成客户端ID的

Answer 10

哦对了，如果你实在不想用我的方式获取Web控件ID，那也行，你直接运行页面，然后右键-》查看网页源文件，找到相应的控件位置的HTML代码，查一下那个控制最终的ID，你直接用这个ID也能JS获取得到，因为它才是最终生成的ID号