在 onActivityResult 中使用相机时出现问题

Question

我有两个选项“选择照片”和“拍照” - 我的选择照片功能可以正常工作，但在拍照时遇到问题。主要是保存后的图像显示在我的图像视图中。

定义了我的照片位置：

public class photoActivity extends Activity {   
      private String photoPath;
      private ImageView imgView;
{...} 

我的摄像头监听器：

bPicFromCam.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {

            String state = Environment.getExternalStorageState();

            if (Environment.MEDIA_MOUNTED.equals(state)) {

                long captureTime = System.currentTimeMillis();

                photoPath = Environment.getExternalStorageDirectory() + "/MYAPP" + captureTime + ".jpg";

                getPicFromCam(v);
            }
            else{

                Toast.makeText(getApplicationContext(),
                    "Sorry there is a problem accessing your SDCard, " +
                    "please select a picture from your gallery instead.", Toast.LENGTH_LONG).show();
            }

        }
    });

然后我的代码启动相机意图（注意photoPath是正确的）：

    public void getPicFromCam(View view){

    System.out.println("photoPath: " + photoPath);
    //Outputs the CORRECT location!

    try{

        Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
        File photo = new File(photoPath);
        intent.putExtra(MediaStore.EXTRA_OUTPUT,
                Uri.fromFile(photo));
        imageUri = Uri.fromFile(photo);
        startActivityForResult(Intent.createChooser(intent, "Capture Image"), CAPTURE_IMAGE);

    } catch (Exception e) {
        Toast.makeText(getApplicationContext(),
                getString(R.string.exception_message),
                Toast.LENGTH_LONG).show();
        Log.e(e.getClass().getName(), e.getMessage(), e);
    }
}

好吧，到目前为止一切都很好 - 拍摄照片并将图像保存到指定位置。

现在我正在尝试在我的图像视图中显示图像（然后可以在用户确认其良好后上传）。

我的 onActivityResult：

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

    switch (requestCode) {
    case PICK_IMAGE:
        if (resultCode == Activity.RESULT_OK) {
            //THIS WORKS
        }
        break;

    case CAPTURE_IMAGE:         

        if (resultCode == RESULT_CANCELED) {
          Toast toast = Toast.makeText(this,"Canceled, no photo selected.", 1000);
          toast.show();
          return;
         }

        if (requestCode == CAPTURE_IMAGE && resultCode == RESULT_OK)
         {

            try {

                System.out.println("photoPath " + photoPath);
                //This is NULL!!!  And my problem, halp!

                BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();  
                bitmapOptions.inSampleSize = 6;  
                bitmap = BitmapFactory.decodeFile(photoPath, bitmapOptions);

                imgView.setImageBitmap(bitmap);


            } catch (Exception e) {
                Toast.makeText(getApplicationContext(), "Internal error",
                        Toast.LENGTH_LONG).show();
                Log.e(e.getClass().getName(), e.getMessage(), e);

            }

         }

        break;
    default:
    }
}

这就是我目前正在尝试的方式，但我也尝试在我的 onActivityResult 中使用以下内容：

bitmap = (Bitmap) data.getExtras().get("data");

但每次我尝试上述方法的变体时，我都会得到一个 NPE。

编辑：

    03-11 19:28:56.319: ERROR/java.lang.NullPointerException(16391): null
03-11 19:28:56.319: ERROR/java.lang.NullPointerException(16391): java.lang.NullPointerException
03-11 19:28:56.319: ERROR/java.lang.NullPointerException(16391):     at com.myco.photoapp.SelectPhoto.onActivityResult(SelectPhoto.java:277)
03-11 19:28:56.319: ERROR/java.lang.NullPointerException(16391):     at android.app.Activity.dispatchActivityResult(Activity.java:3890)
03-11 19:28:56.319: ERROR/java.lang.NullPointerException(16391):     at android.app.ActivityThread.deliverResults(ActivityThread.java:3511)
03-11 19:28:56.319: ERROR/java.lang.NullPointerException(16391):     at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3115)
03-11 19:28:56.319: ERROR/java.lang.NullPointerException(16391):     at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:3143)
03-11 19:28:56.319: ERROR/java.lang.NullPointerException(16391):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2684)
03-11 19:28:56.319: ERROR/java.lang.NullPointerException(16391):     at android.app.ActivityThread.access$2300(ActivityThread.java:125)
03-11 19:28:56.319: ERROR/java.lang.NullPointerException(16391):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
03-11 19:28:56.319: ERROR/java.lang.NullPointerException(16391):     at android.os.Handler.dispatchMessage(Handler.java:99)
03-11 19:28:56.319: ERROR/java.lang.NullPointerException(16391):     at android.os.Looper.loop(Looper.java:123)
03-11 19:28:56.319: ERROR/java.lang.NullPointerException(16391):     at android.app.ActivityThread.main(ActivityThread.java:4627)
03-11 19:28:56.319: ERROR/java.lang.NullPointerException(16391):     at java.lang.reflect.Method.invokeNative(Native Method)
03-11 19:28:56.319: ERROR/java.lang.NullPointerException(16391):     at java.lang.reflect.Method.invoke(Method.java:521)
03-11 19:28:56.319: ERROR/java.lang.NullPointerException(16391):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
03-11 19:28:56.319: ERROR/java.lang.NullPointerException(16391):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
03-11 19:28:56.319: ERROR/java.lang.NullPointerException(16391):     at dalvik.system.NativeStart.main(Native Method)

NPE 出现在以下情况：

//below is line 277
String result = data.toURI();

                BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();  

                bitmapOptions.inSampleSize = 6;  
                bitmap = BitmapFactory.decodeFile(result, bitmapOptions);

Answer 1

当相机 Activity 关闭时，您的 Activity 可能正在被销毁并重新创建。也许尝试在 onSaveInstanceState 中将 photoPath 保存到 Bundle 中，然后在 onCreate 中将其取出（确保在这样做时检查 onCreate 中的空值）？

Answer 2

我无法使用数据。但我认为你需要改变如下

照片成为一般变量。

intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));

所以，你必须从这个文件夹中取出它：

Bitmap photo = Media.getBitmap(getContentResolver(), Uri.fromFile(photo) );

我按照您的代码进行更改。

Answer 3

基本上，使用

intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));

效果很好

在放入 imageView 之前，请确保您压缩了图像，因为以这种方式保存时它非常大。

int newWidth = bm.getWidth();
int newHeight = bm.getHeight();
while(newWidth > 300){
    newWidth = newWidth/2;
newHeight = newHeight/2;
}
mImagePlaceHolder.setImageBitmap(Bitmap.createScaledBitmap(bm, newWidth, newHeight, false));

Answer 4

我在这个问题上苦苦挣扎，并找到了另一个解决方案： 只需使用这样的代码：

Bitmap bitmap = data.getExtras().getParcelable("data");

你可以得到位图。