Question

我正在尝试启动相机并在不活动结果中捕获图像文件，然后将其保存在文件中..但我在getContentResolver.notifyChange行继续获取java.lang.NullPointerException。

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    switch(requestCode) {
        case 1001:
            if(resultCode == Activity.RESULT_OK) {
                getContentResolver().notifyChange(imageUri, null);
                imageView = (ImageView )findViewById(R.id.take_photo_image_view);
                ContentResolver contentResolver = getContentResolver();
                Bitmap bitmap;
                try {
                    bitmap = android.provider.MediaStore.Images.Media.getBitmap(contentResolver,
                      imageUri);
                    imageView.setImageBitmap(bitmap);
                } catch(Exception e) {
                    Toast.makeText(GetPhotoActivity.this, "failed to load",
                    Toast.LENGTH_LONG).show();
                    Log.e(LOG_TAG, e.toString());
                }
            }
    }
}

11-23 17:26:00.508  32727-32727/com.example.testspotter E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.testspotter, PID: 32727
java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1001, result=-1, data=null} to activity {com.example.testspotter/com.example.testspotter.GetPhotoActivity}: java.lang.NullPointerException
        at android.app.ActivityThread.deliverResults(ActivityThread.java:3942)
        at android.app.ActivityThread.handleSendResult(ActivityThread.java:3992)
        at android.app.ActivityThread.access$1300(ActivityThread.java:156)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1403)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:157)
        at android.app.ActivityThread.main(ActivityThread.java:5872)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:515)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:852)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:668)
        at dalvik.system.NativeStart.main(Native Method)
 Caused by: java.lang.NullPointerException
        at android.os.Parcel.readException(Parcel.java:1480)
        at android.os.Parcel.readException(Parcel.java:1428)
        at android.content.IContentService$Stub$Proxy.notifyChange(IContentService.java:486)
        at android.content.ContentResolver.notifyChange(ContentResolver.java:1668)
        at android.content.ContentResolver.notifyChange(ContentResolver.java:1657)
        at android.content.ContentResolver.notifyChange(ContentResolver.java:1637)
        at com.example.testspotter.GetPhotoActivity.onActivityResult(GetPhotoActivity.java:126)

Answer 1

使用以下代码调用相机活动：

Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                    File f = new File(android.os.Environment
                            .getExternalStorageDirectory(), "temp.jpg");
                    intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(f));
                    startActivityForResult(intent, REQUEST_CAMERA);

在onActivityResult

if (resultCode == RESULT_OK) {
            if (requestCode == REQUEST_CAMERA) {
                File f = new File(Environment.getExternalStorageDirectory()
                        .toString());
                for (File temp : f.listFiles()) {
                    if (temp.getName().equals("temp.jpg")) {
                        f = temp;
                        break;
                    }
                }
                try {
                    Bitmap bm;
                    BitmapFactory.Options btmapOptions = new BitmapFactory.Options();
                    imageView = (ImageView )findViewById(R.id.take_photo_image_view);
                    bm = BitmapFactory.decodeFile(f.getAbsolutePath(),
                            btmapOptions);
 
                    // bm = Bitmap.createScaledBitmap(bm, 70, 70, true);
                    imageView.setImageBitmap(bm);
 
                    String path = android.os.Environment
                            .getExternalStorageDirectory()
                            + File.separator
                            + "Phoenix" + File.separator + "default";
                    f.delete();
                    OutputStream fOut = null;
                    File file = new File(path, String.valueOf(System
                            .currentTimeMillis()) + ".jpg");
                    try {
                        fOut = new FileOutputStream(file);
                        bm.compress(Bitmap.CompressFormat.JPEG, 85, fOut);
                        fOut.flush();
                        fOut.close();
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }

带有摄像头图像的Android空指针异常

1 个答案: