cwac-camera crash on zoom to

Question

I'm using the CameraDemo app included with cwac-camera. I'm trying to make the zoom bar change from the main activity using a method updateZoom() but I'm getting a nullpointerexception sometimes from the zoomTo return. Most of the time the zoom will work but then occasionally the program will crash.

Updated zoom:

public void updateZoom()
{
  zoom.setEnabled(false);
   current.zoomTo(zoom.getProgress()).onComplete(new Runnable() {
          @Override
          public void run() {
            zoom.setEnabled(true);
          }
        }).go();
}

Call to updateZoom():

zoom.incrementProgressBy(20);
updateZoom();

Error Logs:

03-01 09:47:55.763: E/AndroidRuntime(31950): FATAL EXCEPTION: main
03-01 09:47:55.763: E/AndroidRuntime(31950): Process: com.commonsware.cwac.camera.demo, PID: 31950
03-01 09:47:55.763: E/AndroidRuntime(31950): java.lang.NullPointerException
03-01 09:47:55.763: E/AndroidRuntime(31950):    at com.commonsware.cwac.camera.CameraFragment.zoomTo(CameraFragment.java:269)
03-01 09:47:55.763: E/AndroidRuntime(31950):    at com.commonsware.cwac.camera.demo.MainActivity.updateZoom(MainActivity.java:163)
03-01 09:47:55.763: E/AndroidRuntime(31950):    at com.commonsware.cwac.camera.demo.MainActivity$1.onPose(MainActivity.java:116)

Answer 1

您呼叫updateZoom()在一个点时， CameraFragment没有CameraView ，所以你得到一个NullPointerException时CameraFragment试图传递zoomTo()调用一起到CameraView 。