將退格鍵按下事件傳遞給小程序並阻止它傳播

Question

我在網頁上有一個允許編輯文本的java小程序。當用戶嘗試修改文本時，按退格按鈕，瀏覽器轉到上一頁。如果過濾器退格按像

var a = function() { 
     var event = window.event; 
     if (event.keyCode == 8){ 
      alert('backspace'); 
      return false; 
     } 
} 
document.onkeydown = a; 

然後backspace不傳播到小程序，因此不會修改文本。 問題是如何將事件傳遞給小程序ant stop進一步傳播？

Answer 1

現在我發現在使用jQuery sendkeys plugin解決方案。由於在我們的項目中使用jQuery不是一個選項，我會嘗試用純JavaScript重寫它。

Answer 2

if (event.keyCode === 8) 
{ 
    var newEvent = document.createEvent('KeyboardEvent'); 
    newEvent.initKeyEvent(                      
       "keypress",  // in DOMString typeArg,               
        true,    // in boolean canBubbleArg,               
        true,    // in boolean cancelableArg,              
        null,    // in nsIDOMAbstractView viewArg, Specifies UIEvent.view. This value may be null.  
        false,   // in boolean ctrlKeyArg,                
        false,   // in boolean altKeyArg,               
        false,   // in boolean shiftKeyArg,              
        false,   // in boolean metaKeyArg,              
        8,    // in unsigned long keyCodeArg,              
        0);    // in unsigned long charCodeArg); 
    document.getElementById('myjavaapplet').dispatchEvent(newEvent); 
} 

Answer 3

if (event.keyCode === 8) 
{ 
    var newEvent = document.createEvent('UIEvents'); 
    newEvent.initUIEvent('keypress', true, true, window, 1); 
    newEvent.keyCode = 8; 
    document.getElementById('myjavaapplet').dispatchEvent(newEvent); 
} 

Answer 4

// assumes IE8, but you could write detection code based on if (document.createEventObject) 

if (event.keyCode === 8) 
{ 
    var newEvent = document.createEventObject(); 
    newEvent.keyCode = 8; 
    document.getElementById('myjavaapplet').fireEvent('onkeypress',newEvent); 
}