asp.net implements the drop down box read only function

2020-05-19 04:34:36
OfStack

 
<HTML> 
<HEAD> 
<TITLE> The drop-down box simulates read-only </TITLE> 
<script type="text/javascript"> 
// According to the drop-down box ID Set the drop-down box to read only  
function setReadOnly(obj_id){ 
var obj = document.getElementById(obj_id); 
obj.onmouseover = function(){ 
obj.setCapture(); 
} 
obj.onmouseout = function(){ 
obj.releaseCapture(); 
} 
obj.onfocus = function(){ 
obj.blur(); 
} 
obj.onbeforeactivate = function(){ 
return false; 
} 
} 
</script> 
</HEAD> 
<BODY> 
<span id="span_select"> 
<select id="id_select"> 
<option value="1">AAAAAAAAA</option> 
<option value="2">BBBBBBBBB</option> 
<option value="3">CCCCCCCCC</option> 
<option value="4">DDDDDDDDD</option> 
</select> 
</span> 
<script type="text/javascript"> 
setReadOnly("span_select"); 
</script> 
<!--  Set the drop-down box to read only  --> 
<select onbeforeactivate="return false" onfocus="this.blur()" onmouseover="this.setCapture()" onmouseout="this.releaseCapture()"> 
</BODY> 
</HTML>

If it is ASP.NET, it is written as follows

 
this.ddlSysCategory.Attributes.Add("onfocus","this.blur();"); 
this.ddlSysCategory.Attributes.Add("onbeforeactivate","return false"); 
this.ddlSysCategory.Attributes.Add("onmouseover","this.setCapture()"); 
this.ddlSysCategory.Attributes.Add("onmouseout","this.releaseCapture()");