Calling Default Phonegap Back Button Handler

问题:

I have a phonegap app that requires I capture the back button. This works swimmingly but when I am at the main screen and the back button is pressed I want to call the original event handler and let the app close or do whatever comes naturally to the platform with such a press. I know I can tell the app to quit but understand this is bad form for iPhone apps.

No matter what I try (and I have tried many things) I cannot get the original handler to fire. Any advice?

In my code I have a switch statement inside my backbutton event handler that directs the app as needed to the effect of:

switch blahBlah {     case 'this' :         doThis() ;         break;     case 'main' :         // What do I do here that is well behaved for all platforms???          break;     default:         doFoo() ; }  

回答1:

Detect whenever you land on the main screen and remove your custom event handler.

document.removeEventListener( "backbutton", function(){}, false ); 

and add the event listener on the other pages (or sections).

document.addEventListener( "backbutton", OverrideBackButton, false ); 

Hope that helps.

回答2:

This is what I've used and it seems to work fine for my needs

        function pageinit() {             document.addEventListener("deviceready", deviceInfo, true);         }           function deviceInfo() {             document.addEventListener("backbutton", onBackButton, true);         }           function onBackButton(e) {             try{                 var activePage = $.mobile.activePage.attr('id');                  if(activePage == 'Options'){                     closeOptions();                 } else if(activePage == 'Popup'){                     closePopup();                 } else if(activePage == 'HomePage'){                  function checkButtonSelection(iValue){                     if (iValue == 2){                             navigator.app.exitApp();                         }                     }                  e.preventDefault();                 navigator.notification.confirm(                     "Are you sure you want to EXIT the program?",                     checkButtonSelection,                     'EXIT APP:',                     'Cancel,OK');                 } else {                      navigator.app.backHistory();                 }             } catch(e){ console.log('Exception: '+e,3); }         } 

Hope this helps...

回答3:

Cordova 7.x, at least on Android, doesn't seem to properly update the override state. As a consequence, @SHANK's answer doesn't work anymore.

As a workaround, you can disable back button overriding manually, resulting in default behavior:

navigator.app.overrideBackbutton(false); 

To re-active custom handling, analogously do:

navigator.app.overrideBackbutton(true); 

I filed a bug report on Apache's issue tracker regarding this.

回答4:

An easy and smooth way to do it could be something like this, this statement worked in my case:

if($("#mainPage").is(".ui-page-active")){       navigator.app.exitApp();  } 

I am using jQuery: http://demos.jquerymobile.com/1.0a3/docs/api/globalconfig.html

regards :)

文章来源: Calling Default Phonegap Back Button Handler