Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
472 views
in Technique[技术] by (71.8m points)

nullpointerexception - Null pointer after capturing image using android camera

in my application,i am using android devices camera to capture an image. for some devices it works fine but some are not. I just tested it on LG nexus 4 E960, after i captured the image my application went crash without able to save the result. this is my code:

//Using intent to open camera
  Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
  startActivityForResult(intent,CAMERA_CAPTURE); 

in the activityResult :

protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
    if(resultCode==RESULT_OK)
    {
        if(requestCode==CAMERA_CAPTURE)
        {   
            Bitmap pictTaken = null ;
            Bundle extras = data.getExtras();
            if(extras.keySet().contains("data"))
            {
                pictTaken = (Bitmap) extras.get("data");
                picUri = getIntent().getData();
            }
                    else{
                     picUri = getIntent().getData();
                try {
                    pictTaken = decodeUri(picUri);
                } catch (FileNotFoundException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                     }
            Intent cropIntent= new Intent (this, Crop.class);
            cropIntent.putExtra("data", picUri.toString());
            cropIntent.putExtra("pict", pictTaken);
            cropIntent.putExtra("code","camera");
            startActivity(cropIntent);
            }
        }

after captured and save it, the image show in next activity called Crop.class here is my logcat

     12-12 13:26:36.340: E/AndroidRuntime(23575): FATAL EXCEPTION: main
 12-12 13:26:36.340: E/AndroidRuntime(23575): Process: com.example.cobaandroid, PID: 23575
 12-12 13:26:36.340: E/AndroidRuntime(23575): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=-1, data=Intent { act=inline-data (has extras) }} to activity {com.example.cobaandroid/com.example.cobaandroid.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.toString()' on a null object reference
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at android.app.ActivityThread.deliverResults(ActivityThread.java:3368)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at android.app.ActivityThread.handleSendResult(ActivityThread.java:3411)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at android.app.ActivityThread.access$1300(ActivityThread.java:138)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1247)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at android.os.Handler.dispatchMessage(Handler.java:102)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at android.os.Looper.loop(Looper.java:136)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at android.app.ActivityThread.main(ActivityThread.java:5050)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at java.lang.reflect.Method.invoke(Native Method)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
 12-12 13:26:36.340: E/AndroidRuntime(23575): Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.toString()' on a null object reference
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at com.example.cobaandroid.MainActivity.onActivityResult(MainActivity.java:226)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at android.app.Activity.dispatchActivityResult(Activity.java:5433)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at android.app.ActivityThread.deliverResults(ActivityThread.java:3364)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   ... 9 more

I got a problem to open/use the camera that work at most android devices, the main goal of this project is heavily depend on the use of the camera. please hand me your help, thank you..

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

try below code,

        Intent i = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);

        File file=getOutputMediaFile(1);
        picUri = Uri.fromFile(file); // create
        i.putExtra(MediaStore.EXTRA_OUTPUT,picUri); // set the image file

        startActivityForResult(i, CAPTURE_IMAGE);

where getOutputMediaFile(int) will be,

/** Create a File for saving an image */
private  File getOutputMediaFile(int type){
    File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
              Environment.DIRECTORY_PICTURES), "MyApplication");

    /**Create the storage directory if it does not exist*/
    if (! mediaStorageDir.exists()){
        if (! mediaStorageDir.mkdirs()){
            return null;
        }
    }

    /**Create a media file name*/
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    File mediaFile;
    if (type == 1){
        mediaFile = new File(mediaStorageDir.getPath() + File.separator +
        "IMG_"+ timeStamp + ".png");
    } else {
        return null;
    }

    return mediaFile;
}

and finally,

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == Activity.RESULT_OK) {
        Intent i;
        switch (requestCode) {
        case CAPTURE_IMAGE:
            //THIS IS YOUR Uri
            Uri uri=picUri; 
            break;
        }
    }   
}

Cheers....:)


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...