javascript技术技巧大全（三）

2022-07-15 80酷酷网 80kuku.com

　　技巧//计算内容宽和高 <SCRIPT  language="javascript">
function  test(obj)
{
       var  range  =  obj.createTextRange();
       alert("内容区宽度:  "  +  range.boundingWidth
                                                 +  "px\r\n内容区高度:  "  +  range.boundingHeight  +  "px");

}
</SCRIPT>
<BODY>
<Textarea id="txt" height="150">sdf</textarea><INPUT  type="button"  value="计算内容宽度"  >
</BODY>

//无模式的提示框 function modelessAlert(Msg)
{
window.showModelessDialog("javascript:alert(\""+escape(Msg)+"\");window.close();","","status:no;resizable:no;help:no;dialogHeight:height:30px;dialogHeight:40px;");
}

//屏蔽按键

<html>
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=gb2312">
  <noscript><meta http-equiv="refresh" content="0;url=about:noscript"></noscript>
  <title>屏蔽鼠标右键、Ctrl+N、Shift+F10、Alt+F4、F11、F5刷新、退格键</title>
</head>
<body>
<script language="Javascript"><!--
  //屏蔽鼠标右键、Ctrl+N、Shift+F10、F11、F5刷新、退格键
  //Author: meizz(梅花雨) 2002-6-18
function document.oncontextmenu(){event.returnValue=false;}//屏蔽鼠标右键
function window.onhelp(){return false} //屏蔽F1帮助
function document.onkeydown()
{
  if ((window.event.altKey)&&
      ((window.event.keyCode==37)||   //屏蔽 Alt+ 方向键 ←
       (window.event.keyCode==39)))   //屏蔽 Alt+ 方向键 →
  {
     alert("不准你使用ALT+方向键前进或后退网页！");
     event.returnValue=false;
  }
     /* 注：这还不是真正地屏蔽 Alt+ 方向键，
     因为 Alt+ 方向键弹出警告框时，按住 Alt 键不放，
     用鼠标点掉警告框，这种屏蔽方法就失效了。以后若
     有哪位高手有真正屏蔽 Alt 键的方法，请告知。*/
  if ((event.keyCode==8)  ||                 //屏蔽退格删除键
      (event.keyCode==116)||                 //屏蔽 F5 刷新键
      (event.ctrlKey && event.keyCode==82)){ //Ctrl + R
     event.keyCode=0;
     event.returnValue=false;
     }
  if (event.keyCode==122){event.keyCode=0;event.returnValue=false;}  //屏蔽F11
  if (event.ctrlKey && event.keyCode==78) event.returnValue=false;   //屏蔽 Ctrl+n
  if (event.shiftKey && event.keyCode==121)event.returnValue=false;  //屏蔽 shift+F10
  if (window.event.srcElement.tagName == "A" && window.event.shiftKey)
      window.event.returnValue = false;             //屏蔽 shift 加鼠标左键新开一网页
  if ((window.event.altKey)&&(window.event.keyCode==115))             //屏蔽Alt+F4
  {
      window.showModelessDialog("about:blank","","dialogWidth:1px;dialogheight:1px");
      return false;
  }
}
</script>
屏蔽鼠标右键、Ctrl+N、Shift+F10、Alt+F4、F11、F5刷新、退格键
</body>
</html>

//屏蔽打印
<style>
media print{
* {display:none}
}
</style>

//移动的图层，拖动

1.<span
<script language=javascript>
var Obj;
function MouseDown(obj)
{
  Obj=obj;
  Obj.setCapture();
  Obj.l=event.x-Obj.style.pixelLeft;
  Obj.t=event.y-Obj.style.pixelTop;
}
function MouseMove()
{
  if(Obj!=null)
  {
    Obj.style.left = event.x-Obj.l;
    Obj.style.top = event.y-Obj.t;
  }
}
function MouseUp()
{
  if(Obj!=null)
  {
    Obj.releaseCapture();
    Obj=null;
  }
}
</script>
2.
<div id="myDiv" src="http://www.163design.net/j/e/logo.gif" ondrag="doDrag();"
<a
var orgMouseX;
var orgMouseY;
var orgObjX;
var orgObjY;
function doDrag()
{
var myObject=document.all.myDiv;

var x=event.clientX;
var y=event.clientY;
myObject.style.left=x-(orgMouseX-orgObjX);
myObject.style.top=y-(orgMouseY-orgObjY);

}
function doMouseDown()
{
orgMouseX=event.clientX;
orgMouseY=event.clientY;
orgObjX=parseInt(document.all.myDiv.style.left);
orgObjY=parseInt(document.all.myDiv.style.top);
}

</script>

//文档状态改变