navigator.camera.getPicture callback doesn't execute until 2nd call

问题

I've got a phonegap (cordova) app running cordova 3.1.0 and when I call

navigator.camera.getPicture(success,fail,options)

with options as

var options={ 
        destinationType: navigator.camera.DestinationType.FILE_URI,
        sourceType: navigator.camera.PictureSourceType.SAVEDPHOTOALBUM,
        encodingType: navigator.camera.EncodingType.JPEG,
        mediaType: navigator.camera.MediaType.Picture
}

the success callback isn't called after the photo is selected by the user.

If I then call

navigator.camera.getPicture(success,fail,options)

again, the success callback from the first getPicture is called with the photo selected in the first step.

I've poked around in CameraLauncher.java (around line 395 onwards) and it seems that it calls

this.callbackContext.success(uri.toString());

onActivtyResult but this doesn't seem to be passed back until the next getPicture() call.

Anybody else come across this?

Further digging shows the same thing happening when calling getPicture from camera too.

I'm wondering if it's because when the camera activity finishes the webview hasn't resumed so the callback has nowhere to go - but this is wild speculation at best.

24 hours later, it seems that updating to Cordova 3.1.0.jar and dropping the 3.1 jar directly into an existing 3.0 project resolved this issue.

回答1:

So, what was happening was that on Android only the callback for getPicture was being triggered by requesting getPicture a second time.

This was resolved by updating my cordova install, creating an empty android project and then copying the /platforms/android/libs/cordova-3.1.0.jar from it, into /platforms/android/libs in my existing project and removing cordova-3.0.0.jar

Hope this saves somebody an hour or 3...

回答2:

I tried the solution documented here for a similar issue with the barcode scanner, and it worked. https://github.com/zeroasterisk/MeteorRider/issues/16 (as referred to from here: https://github.com/wildabeast/BarcodeScanner/issues/107)

To summarize, it appears that the Android event pipeline gets "clogged", and you can run this code before your normal cordova plugin call to clear it.

if (device.platform === 'Android') {
  setInterval(function () {
     cordova.exec(null, null, '', '', [])
  }, 200);
}

来源：https://stackoverflow.com/questions/19809164/navigator-camera-getpicture-callback-doesnt-execute-until-2nd-call

标签

cordova

callback

camera

navigator