您的位置：首页 > Web前端 > JavaScript

使用javascript屏蔽web页面上特定按键事件和右键菜单

2005-08-29 17:52 721 查看

简介

本文将介绍如何在web页面上禁用特定的按键，如Shift、Ctrl等，以及如何禁用右键菜单。下面介绍的方法适用于当前大多数浏览器。

代码实现

定义javascript 函数，并且将其作为页面body的onload事件的处理函数。

<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<script type="text/javascript">
  function restrainIllegalOperation(){
     document.onkeydown = keyEventHandle;
     document.oncontextmenu = contextEventHandle; 
  }

  function keyEventHandle(e) {
      // The information under keys is registered.
      var shift, ctrl, alt;
    
      // Mozilla(Firefox, NN) and Opera
      if (e != null) {
          keycode = e.which;
          ctrl    = typeof e.modifiers == 'undefined' ? e.ctrlKey : e.modifiers & Event.CONTROL_MASK;
          shift   = typeof e.modifiers == 'undefined' ? e.shiftKey : e.modifiers & Event.SHIFT_MASK;
          alt   = typeof e.modifiers == 'undefined' ? e.altKey : e.modifiers & Event.ALT_MASK;
      // Internet Explorer
      } else {
          keycode = event.keyCode;
          ctrl    = event.ctrlKey;
          shift   = event.shiftKey;
          alt     = event.altKey;
      }

      // Ctrl + R
      if((ctrl && keycode == 82) || (ctrl == 17 && keycode == 82)) {
          // Mozilla(Firefox, NN) and Opera
          if (e != null) {
              // The higher rank propagation of an event is prevented. 
            e.which = 0;
              e.preventDefault();
              e.stopPropagation();
          // Internet Explorer
          } else {
              // The higher rank propagation of an event is prevented. 
            event.keyCode = 0;
              event.returnValue = false;
              event.cancelBubble = true;
          }
          return false;
      }
      
      // Ctrl + F5
      if((ctrl && keycode == 116) || (ctrl == 17 && keycode == 116)) {
          // Mozilla(Firefox, NN) and Opera
          if (e != null) {
              // The higher rank propagation of an event is prevented. 
            e.which = 0;
              e.preventDefault();
              e.stopPropagation();
          // Internet Explorer
          } else {
              // The higher rank propagation of an event is prevented. 
            event.keyCode = 0;
              event.returnValue = false;
              event.cancelBubble = true;
          }
          return false;
      }
      
      // F5
      if(keycode == 116) {
          // Mozilla(Firefox, NN) and Opera
          if (e != null) {
              // The higher rank propagation of an event is prevented. 
            e.which = 0;
              e.preventDefault();
              e.stopPropagation();
          // Internet Explorer
          } else {
              // The higher rank propagation of an event is prevented. 
            event.keyCode = 0;
              event.returnValue = false;
              event.cancelBubble = true;
          }
          return false;
      }
      
      // Alt 
      if((alt && keycode == 37) || (alt == 18 && keycode == 37)) {
          // Mozilla(Firefox, NN) and Opera
          if (e != null) {
              // The higher rank propagation of an event is prevented. 
            e.which = 0;
              e.preventDefault();
              e.stopPropagation();
          }
          return false;
      }

      // ESC
      if(keycode == 27) {
          // Mozilla(Firefox, NN) and Opera
          if (e != null) {
              // The higher rank propagation of an event is prevented. 
            e.which = 0;
              e.preventDefault();
              e.stopPropagation();
          // Internet Explorer
          } else {
              // The higher rank propagation of an event is prevented. 
            event.keyCode = 0;
              event.returnValue = false;
              event.cancelBubble = true;
          }
          return false;
      }

      // BackSpace
      if(keycode == 8) {
          if ((document.activeElement.type == "text") || 
            (document.activeElement.type == "textarea") ||
            (document.activeElement.type == "password") ||
            (document.activeElement.type == "file")) {
              if(!document.activeElement.readOnly) {
                  return true;
              }
          }
          // Mozilla(Firefox, NN) and Opera
          if (e != null) {
              // The higher rank propagation of an event is prevented. 
            e.which = 0;
              e.preventDefault();
              e.stopPropagation();
          // Internet Explorer
          } else {
              // The higher rank propagation of an event is prevented. 
            event.keyCode = 0;
              event.returnValue = false;
              event.cancelBubble = true;
          }
          return false;
      }

      // Mozilla(Firefox, NN) and Opera
      if (e != null) {
        // In MacOS, Cmd+R (renewal of a Web page and cash) deters.
        if (e.metaKey && keycode == 82) {
          return false;
        }
        
        // In MacOS, it is Cmd+. Control of [(it moves to a front page) 
        if (e.metaKey && keycode == 219) {
          return false;
        }
      }

  }

  function contextEventHandle() {
      return false;
  }
</script>

<title></title>
</head>
<body onload="restrainIllegalOperation()">
  Prevent special keys and context menu.
</body>
</html>

本文译自Prevent user hit some special keywords(Ctrl, Shift...) and access context menu on webpage

内容来自用户分享和网络整理，不保证内容的准确性，如有侵权内容，可联系管理员处理

标签：

相关文章推荐

新的分享

章节导航