Datalist里checkbox JS全选问题，急，高分!

Question

<a href="javascript:check(true);">Select All</a>/<a href="javascript:check(false);">Clear 
All</a><datalist id="dl"...
<itemtemplate>
名称
编号
<asp:checkbox id="selectid".../>
</itemtemplate>
</datalist>之前我用html控件的<input type=checkbox，实现了全选
function check(checked)
{
  for(var i=0;i<Form1.SelectProductID.length;i++)
  {  
  Form1.SelectProductID[i].checked=checked;
  }但换为<asp:checkbox就没反应了，请教怎么写
JS 全选怎么写，
高分

Answer 1

function chkAll_true()
{
                var chkall= document.all["chkAll"];
                var chkother= document.getElementsByTagName("input");
                for (var i=0;i<chkother.length;i++)
                {
                    if( chkother[i].type=='checkbox')
                    {
                        if(chkother[i].id.indexOf('selectid')>-1)
                        {
                            if(chkall.checked==true)
                            {
                                chkother[i].checked=true;
                            }
                            else
                            {
                                chkother[i].checked=false;
                            }
                        }
                    }
                }
}

Answer 2

function check(trueorfalse)
{
                var chkother= document.getElementsByTagName("input");
                for (var i=0;i<chkother.length;i++)
                {
                    if( chkother[i].type=='checkbox')
                    {
                        if(chkother[i].id.indexOf('selectid')>-1)
                        {
                            if(trueorfalse==true)
                            {
                                chkother[i].checked=true;
                            }
                            else
                            {
                                chkother[i].checked=false;
                            }
                        }
                    }
                }
}

Answer 3

全选
function SelectAll()
   {
    var len=document.Form1.elements.length;
    var i;
    for (i=0;i<len;i++)
    {
     if (document.Form1.elements[i].type=="checkbox")
     {
      document.Form1.elements[i].checked=true;        
     }
    }
   }

Answer 4

全部取消选择只需要把 document.Form1.elements[i].checked=true; 改为
 document.Form1.elements[i].checked=false;就可以了

Answer 5

你用“datagrid＋checkbox"可以看到相关blog或者网页为你答疑，其次建议多去lovecherry的blog看看