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Android：使用相机意图时，应用程序在onActivityResult上崩溃

androidandroid-camera-intent
17

我正在使用相机意图在我的应用程序中捕获图像。问题是，在使用相机时，我的应用程序会在 Android 5.0.2 上崩溃。我正在从片段中使用意图。以下是片段内的代码：

拍照方法

private void takePhoto() {
    mHighQualityImageUri = Util.generateTimeStampPhotoFileUri(getActivity());
    Log.d(UploadPicturesFragment.class.getSimpleName(),
            "URI: " + mHighQualityImageUri.toString());
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    intent.putExtra(MediaStore.EXTRA_OUTPUT, mHighQualityImageUri);
    startActivityForResult(intent, REQUEST_IMAGE_CAPTURE);
}

在我的片段中的onActivityResult

public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode != Activity.RESULT_OK) {
        return;
    }

    if (requestCode == REQUEST_IMAGE_CAPTURE) {
    Log.d(UploadPicturesFragment.class.getSimpleName(),
                "IMAGE URI NOT NULL: " + (mHighQualityImageUri == null));
        try {
            Bitmap bitmap = MediaStore.Images.Media.getBitmap(getActivity().getContentResolver(),
                    mHighQualityImageUri);
            DroomUtil.beginCrop(mHighQualityImageUri, getActivity(), this, true, bitmap.getWidth(),
                    bitmap.getHeight());
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

日志追踪

12-29 10:28:03.491: E/AndroidRuntime(9780): java.lang.RuntimeException:       Unable to resume activity {in.droom/in.droom.activity.MainActivity}:     java.lang.RuntimeException: Failure delivering result    ResultInfo{who=android:fragment:2, request=1, result=-1, data=null} to activity   {in.droom/in.droom.activity.MainActivity}: java.lang.NullPointerException:   Attempt to invoke virtual method 'java.lang.String android.net.Uri.getScheme()'   on a null object reference
12-29 10:28:03.491: E/AndroidRuntime(9780):     at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3224)
12-29 10:28:03.491: E/AndroidRuntime(9780):     at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:3257)
12-29 10:28:03.491: E/AndroidRuntime(9780):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2479)
12-29 10:28:03.491: E/AndroidRuntime(9780):     at android.app.ActivityThread.access$800(ActivityThread.java:144)
12-29 10:28:03.491: E/AndroidRuntime(9780):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1359)
12-29 10:28:03.491: E/AndroidRuntime(9780):     at android.os.Handler.dispatchMessage(Handler.java:102)
12-29 10:28:03.491: E/AndroidRuntime(9780):     at android.os.Looper.loop(Looper.java:155)
12-29 10:28:03.491: E/AndroidRuntime(9780):     at android.app.ActivityThread.main(ActivityThread.java:5702)
12-29 10:28:03.491: E/AndroidRuntime(9780):     at java.lang.reflect.Method.invoke(Native Method)
12-29 10:28:03.491: E/AndroidRuntime(9780):     at java.lang.reflect.Method.invoke(Method.java:372)
12-29 10:28:03.491: E/AndroidRuntime(9780):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1029)
12-29 10:28:03.491: E/AndroidRuntime(9780):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:824)
12-29 10:28:03.491: E/AndroidRuntime(9780): Caused by: java.lang.RuntimeException: Failure delivering result ResultInfo{who=android:fragment:2, request=1, result=-1, data=null} to activity {in.droom/in.droom.activity.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.getScheme()' on a null object reference
12-29 10:28:03.491: E/AndroidRuntime(9780):     at android.app.ActivityThread.deliverResults(ActivityThread.java:3881)
12-29 10:28:03.491: E/AndroidRuntime(9780):     at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3197)
12-29 10:28:03.491: E/AndroidRuntime(9780):     ... 11 more
12-29 10:28:03.491: E/AndroidRuntime(9780): Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.getScheme()' on a null object reference
12-29 10:28:03.491: E/AndroidRuntime(9780):     at android.content.ContentResolver.openInputStream(ContentResolver.java:651)
12-29 10:28:03.491: E/AndroidRuntime(9780):     at android.provider.MediaStore$Images$Media.getBitmap(MediaStore.java:1019)
12-29 10:28:03.491: E/AndroidRuntime(9780):     at in.droom.fragments.UploadPicturesFragment.onActivityResult(UploadPicturesFragment.java:395)
12-29 10:28:03.491: E/AndroidRuntime(9780):     at android.app.Activity.dispatchActivityResult(Activity.java:6164)
12-29 10:28:03.491: E/AndroidRuntime(9780):     at android.app.ActivityThread.deliverResults(ActivityThread.java:3877)
12-29 10:28:03.491: E/AndroidRuntime(9780):     ... 12 more

第395行是：

Bitmap bitmap = MediaStore.Images.Media.getBitmap(getActivity().getContentResolver(),
                    mHighQualityImageUri);
https://dev59.com/zWox5IYBdhLWcg3wvW3X#11351580 - therealprashant
我认为你正在某个地方结束你的活动。 - Vivek Mishra
@VivekMishra 但问题只出现在Android 5.0.2上。 - Nitish
@VivekMishra 不是的。我发现有时候当相机打开时，它的方向从横向变成纵向。我的应用程序只支持纵向模式。 - Nitish
有时候我也会在Intent中得到null。在我的情况下，如果我在相机打开时旋转设备，那么我会在onActivityResult中得到null。 - Vivek Mishra
显示剩余5条评论
8个回答
12
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.getScheme()' on a null object reference

这意味着mHighQualityImageUri很可能是null。如果您没有使用onSaveInstanceState()保存Uri，则会发生这种情况。很有可能在您的应用程序位于后台并且相机应用程序处于前台时，您的进程将被终止。

@CommonsWare 不是null，但仍然出现相同的错误。 - Junaid
如果我正确理解了您的问题，在相机应用程序在前台时，请从Android Studio终止您的应用程序进程。然后，使用相机拍照。当控制权返回到您的应用程序时，Android将需要为您派生一个新的进程。 - CommonsWare
6

以下是按顺序进行的步骤，以从相机中拍摄照片并显示在ImageView上。

1）启动相机意图

Uri fileUri;
String photoPath = "";

 private void startingCameraIntent()
    {
        String fileName = System.currentTimeMillis()+".jpg";
        ContentValues values = new ContentValues();
        values.put(MediaStore.Images.Media.TITLE, fileName);
        fileUri = getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);

        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
        startActivityForResult(intent, YOUR_REQ_CODE);
    }

2) onActivityResult 回调函数

@Override
    public void onActivityResult(int requestCode, int resultCode, Intent data)
    {
        if (resultCode == Activity.RESULT_OK)
        {
            try
            {
                photoPath = getPath(fileUri);

                System.out.println("Image Path : " + photoPath);

                Bitmap b = decodeUri(fileUri);
                your_image_view.setImageBitmap(b);
            }
            catch(Exception e)
            {
                e.printStackTrace();
            }
        }
    }

3) decodeUri Function

private Bitmap decodeUri(Uri selectedImage) throws FileNotFoundException
    {
        BitmapFactory.Options o = new BitmapFactory.Options();

        o.inJustDecodeBounds = true;

        BitmapFactory.decodeStream(getContentResolver()
                                           .openInputStream(selectedImage), null, o);

        final int REQUIRED_SIZE = 72;

        int width_tmp = o.outWidth, height_tmp = o.outHeight;

        int scale = 1;

        while (true)
        {
            if (width_tmp / 2 < REQUIRED_SIZE || height_tmp / 2 < REQUIRED_SIZE)
            {
                break;
            }
            width_tmp /= 2;

            height_tmp /= 2;

            scale *= 2;
        }

        BitmapFactory.Options o2 = new BitmapFactory.Options();

        o2.inSampleSize = scale;

        Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver()
                                                           .openInputStream(selectedImage), null, o2);

        return bitmap;
    }

4) 获取图片路径

@SuppressWarnings("deprecation")
    private String getPath(Uri selectedImaeUri)
    {
        String[] projection = { MediaStore.Images.Media.DATA };

        Cursor cursor = managedQuery(selectedImaeUri, projection, null, null,
                                     null);

        if (cursor != null)
        {
            cursor.moveToFirst();

            int columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);

            return cursor.getString(columnIndex);
        }

        return selectedImaeUri.getPath();
    }

最后 在清单文件中定义权限 

 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
注意: 如果您正在使用棉花糖(Android 6.0)系统, 在使用相机应用程序之前, 您需要设置权限检查。您可以阅读有关请求运行时Android权限请求的内容。
5

首先，在onActivityResult中检查data是否为null，通过添加额外的代码来防止应用程序崩溃，像这样：

public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode != Activity.RESULT_OK && data !=null) {
    return;
}
}

那么考虑一下这个课程，它解释了如何使用现有的相机应用程序拍照。

关于使用请求相机权限和uses-feature标签，获取缩略图，保存全尺寸照片等方面有完整的参考资料，这些可能对您完成任务非常有帮助...

数据！= null 是正确的吗？为什么不是“数据== null”？ - Hill
2

根据日志记录

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.getScheme()' on a null object reference

该错误清晰地说明您在空对象上调用了getScheme()。因此，在处理之前，您需要检查意图数据是否为空。

此外，在Android M及以上版本中，您需要请求用户授予相机权限。如果没有相机权限，应用程序将崩溃。

要了解如何使用新的权限架构，请参阅：http://developer.android.com/training/permissions/index.html

2
在安卓设备上，我发现不同的设备在使用相机和图库选择图片时表现出不同的行为。我认为更好的方法是：
  1. 在您的应用程序中创建内容提供者。
  2. 从您的内容提供者获取Uri，并将其传递给相机意图。
  3. 相机会将捕获的图像写入您的Uri。
  4. 使用context.getContentResolver().openInputStream()读取它。
这种方法使您的代码独立于意图返回的Uri，因为您拥有该Uri。此外，通过进行小的修改，这也支持从图库中选择图像。
我还注意到您在相机方面存在设备方向问题。这（不幸的是）需要在后处理步骤中在您的应用程序中进行处理，一旦您获取了图像，就需要进行处理。我也在下面概述了它的代码。大多数情况下，在三星设备上发生方向问题，其中相机仅以横向模式捕获图像。 创建图像的Uri： 
string imageId = "IMG" + System.currentTimeMillis();
Uri attachmentUri = Uri.parse("content://"+ AttachmentContentProvider.AUTHORITY + "/images/" + imageId); 
// Store this as a member in your activity/fragment as mAttachmentUri

注意：在你的应用被杀掉时，如果不使用SharedPreferences或者Activity bundle的onSaveInstanceState()方法持久化保存mAttachmentUri Uri对象的话，该对象可能会丢失。

获取相机意图：

public static Intent getImageCaptureIntent(Context context, Uri outputFileUri)
{
    Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);
    return cameraIntent;
}

读取图片：

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) 
{
    if (resultCode != Activity.RESULT_OK) {
        return;
    }

    if (requestCode == REQUEST_IMAGE_CAPTURE) 
    {

        try {
            Bitmap bitmap = decodeSampledBitmapFromResource(getActivity(), mAttachmentUri, Config.RGB_565);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

    public static Bitmap decodeSampledBitmapFromResource(Context context, Uri uri, Config config)
    { 
        Bitmap bmp = null;
        InputStream is = null;
        if (uri != null)
        {
            try
            {
                is = context.getContentResolver().openInputStream(uri);

                boolean resize = true;
                // First decode with inJustDecodeBounds=true to check dimensions
                BitmapFactory.Options options = new BitmapFactory.Options();
                options.inJustDecodeBounds = true;
                BitmapFactory.decodeStream(is, null, options);
                mLogger.d("Image Original Width:" + options.outWidth + " Height:" + options.outHeight );
                // close and open the stream again
                is.close();

                is = context.getContentResolver().openInputStream(uri);
                int reqWidth = options.outWidth;
                int reqHeight = options.outHeight;

                // Decode bitmap with inSampleSize set
                options.inJustDecodeBounds = false;
                options.inPreferredConfig = config;     
                bmp = BitmapFactory.decodeStream(is, null, options);

                if(bmp != null)
                {
                    bmp = correctImageRotation(context, bmp, uri);
                }
                else
                {
                    mLogger.e("BitmapFactory.decodeStream returned null bitmap , skip correctImageRotation");
                }
            }
            catch (FileNotFoundException fnfex)
            {
                mLogger.e("FileNotFoundException : while decoding inline image bitmap: " + fnfex.getMessage());
            }
            catch (IOException ioex)
            {
                mLogger.e("IOException : while decoding inline image bitmap: " + ioex.getMessage());
            }
            catch (OutOfMemoryError e)
            {
                mLogger.e("OutOfMemoryError : in decodeSampledBitmapFromResource BitmapFactory.decodeStream . Skip loading Resource");
            }
            finally
            {
                try
                {
                    if (is != null)
                    {
                        is.close();
                    }
                }
                catch (IOException ioex2)
                {
                    mLogger.e("IOException2 : while decoding inline image bitmap: " + ioex2.getMessage());
                }
            }
        }
        return bmp;
    }

    // Seemed necessary on a lot of Samsung devices
    public static Bitmap correctImageRotation( Context context, Bitmap bitmap , Uri inputUri ) throws FileNotFoundException
    {
        int orientation = ExifInterface.ORIENTATION_UNDEFINED;

        try
        {
            String appfilesDir = context.getApplicationContext().getFilesDir().getAbsolutePath();
            String attachmentDirPath = appfilesDir + ('/') + "images");
            String fileName = ContentUris.parseId(uri) + ".jpg";
            String absolutePath = attachmentDirPath + ('/') + fileName;
            ExifInterface exif = new ExifInterface(path);
            orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_UNDEFINED);
        }
        catch (IOException e)
        {
        }

        return rotateBitmap(bitmap, orientation);
    }

    /**
     * rotate bitmap code reference:
     * https://dev59.com/7WIj5IYBdhLWcg3wPy0a
     */
    private static Bitmap rotateBitmap(Bitmap bitmap, int orientation)
    {
        Matrix matrix = new Matrix();
        switch (orientation)
        {
        case ExifInterface.ORIENTATION_FLIP_HORIZONTAL:
            matrix.setScale(-1, 1);
            break;
        case ExifInterface.ORIENTATION_ROTATE_180:
            matrix.setRotate(180);
            break;
        case ExifInterface.ORIENTATION_FLIP_VERTICAL:
            matrix.setRotate(180);
            matrix.postScale(-1, 1);
            break;
        case ExifInterface.ORIENTATION_TRANSPOSE:
            matrix.setRotate(90);
            matrix.postScale(-1, 1);
            break;
        case ExifInterface.ORIENTATION_ROTATE_90:
            matrix.setRotate(90);
            break;
        case ExifInterface.ORIENTATION_TRANSVERSE:
            matrix.setRotate(-90);
            matrix.postScale(-1, 1);
            break;
        case ExifInterface.ORIENTATION_ROTATE_270:
            matrix.setRotate(-90);
            break;
        case ExifInterface.ORIENTATION_NORMAL:
        case ExifInterface.ORIENTATION_UNDEFINED:
        default:
            return bitmap;
        }
        try
        {
            Bitmap bmRotated = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
            bitmap.recycle();
            return bmRotated;
        }
        catch (OutOfMemoryError e)
        {
            mLogger.e("OutOfMemoryError occured while rotating the image");
            return bitmap;
        }
    }

内容提供者：

对于内容提供者的实现，您可以使用android的FileProvider或像下面这样实现一个内容提供者。这个内容提供者将打开您应用程序容器中的一个文件，供相机应用程序进行写入。

public class AttachmentContentProvider extends ContentProvider 
{
    public static final String AUTHORITY = "com.yourcompany.yourapp.AttachmentContentProvider";
    public static final int ENTITY_ATTACHMENT = 1;
    public static final int ENTITY_ATTACHMENT_ID = 2;

    private static final UriMatcher sUriMatcher;
    static 
    {
        sUriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
        sUriMatcher.addURI(AUTHORITY, "images", ENTITY_ATTACHMENT);
        sUriMatcher.addURI(AUTHORITY, "images"+"/#", ENTITY_ATTACHMENT_ID);
    }

    @Override
    public boolean onCreate()
    {
        return true;
    }

    @Override
    public int delete(Uri uri, String where, String[] whereArgs)
    {
        return 0;
    }

    @Override
    public String getType(Uri uri)
    {
        int match = sUriMatcher.match(uri);
        switch (match) 
        {
        case ENTITY_ATTACHMENT:
        case ENTITY_ATTACHMENT_ID:
            return "image/jpeg";

        default:
            return null;
        }
    }

    @Override
    public Uri insert(Uri uri, ContentValues initialValues)
    {
        return null;
    }

    @Override
    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder)
    {
        return null;
    }

    @Override
    public int update(Uri uri, ContentValues values, String where, String[] whereArgs)
    {
        return 0;
    }

    public static File getAttachmentFile(String fileName)
    {
        String appfilesDir = context.getApplicationContext().getFilesDir().getAbsolutePath();
        String attachmentDirPath = appfilesDir + ('/') + "images");
        File newFile = new File(AttachmentHelper.getAttachmentsDir() + File.separator + fileName);
        newFile.getParentFile().mkdirs();
        return newFile;
    }


    @Override
    public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException 
    {
        long id = -1;
        try
        {
            id = ContentUris.parseId(uri);
        }
        catch (NumberFormatException e)
        {
            m_logger.e("Invalid id for Uri : " + uri );
        }

        String filename  = id + ".jpg"; // id will be IMG+current time millis
        File imageFile = getAttachmentFile(id); 
        return (ParcelFileDescriptor.open(file, parseMode(mode)));
    }
}

总之，这段代码应该适用于大多数已经测试过的设备，并且在需要时对从相机接收到的图像进行了校正。
2
    please check your path from mHighQualityImageUri because output path is not found, below code is modify please check it, it work and remember camera result is give in Main Activity class because You used Fragment so declare on activity Result in Main Activity (Fragment Activity) class.   
//on Fragment Class
private void takePhoto() {
             /*   mHighQualityImageUri = Util.generateTimeStampPhotoFileUri(getActivity());
                Log.d(UploadPicturesFragment.class.getSimpleName(),
                        "URI: " + mHighQualityImageUri.toString());*/
                imageUri =Uri.fromFile(new File("/sdcard/"));
                Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
                context.startActivityForResult(intent, REQUEST_IMAGE_CAPTURE);
            }

    //on Main Activity Class
      @Override
        protected void onActivityResult(int requestCode, int resultCode, Intent data) {
            if (requestCode == 1) {
             /*   Log.d(UploadPicturesFragment.class.getSimpleName(),
                        "IMAGE URI NOT NULL: " + (mHighQualityImageUri == null));*/
                try {

                    /*if(imageUri==null){
                        Log.i("Bitmap", "Image URI Null");
                    }else {
                        Log.i("Bitmap","Image URI is not Null");
                    }*/
                    Uri imageUri = Uri.fromFile(new File("/sdcard/"));
                    Bitmap bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(),imageUri);
    //                        mHighQualityImageUri);
                    if(bitmap !=null)
                    {
                        Log.i("Bitmap", "Bitmap not Null");
                    }else {
                        Log.i("Bitmap","Bitmap is Null");
                    }
                    //  DroomUtil.beginCrop(mHighQualityImageUri, getActivity(), this, true, bitmap.getWidth(),
                    // bitmap.getHeight());
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            super.onActivityResult(requestCode, resultCode, data);
        }
0

这是我在项目中经常做的事情，请看一下。希望能有所帮助！

片段类：

btnCapturePicture.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {       
        captureImage();     
    }
});

btnSelectPicture.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {       
        selectImage();
    }
});

...

private void captureImage() {
    mFileUri = Uri.fromFile(Utils.getOutputMediaFile(MEDIA_TYPE_IMAGE));
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    intent.putExtra(MediaStore.EXTRA_OUTPUT, mFileUri);
    startActivityForResult(intent, CAMERA_CAPTURE_IMAGE_REQUEST_CODE);
}

private void selectImage() {    
    Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
    intent.setType(MIME_IMAGE_ALL); 
    startActivityForResult(intent, SELECT_PHOTO_CODE);
}

...

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

    switch (requestCode) {
        case SELECT_PHOTO_CODE:
            if (resultCode == Activity.RESULT_OK) {
                mFileUri = imageReturnedIntent.getData();
                if (mFileUri != null) {
                    mFilePath = Utils.getRealPathFromUri(mContext, mFileUri);
                    mFilePath = mFilePath.replace("file://", "");
                    // do something such as display ImageView...
                }
            }
            break;
        case CAMERA_CAPTURE_IMAGE_REQUEST_CODE:
            if (resultCode == Activity.RESULT_OK) {
                if (mFileUri != null) {
                    mFilePath = mFileUri.toString();
                    mFilePath = mFilePath.replace("file://", "");
                    // do something such as display ImageView...
                }
            }
            break;
    }

    // refresh phone's folder content
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
        Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);     
        mediaScanIntent.setData(mFileUri);
        getActivity().sendBroadcast(mediaScanIntent);
    } else {
        getActivity().sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://" + Environment.getExternalStorageDirectory())));
    }
}

工具类：

//returning image, video
public static File getOutputMediaFile(int type) {

    // External sdcard location
    File mediaStorageDir = new File(Environment.getExternalStorageDirectory(), "DCIM/Camera");

    // 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", Locale.getDefault()).format(new Date());
    File mediaFile;
    if (type == MEDIA_TYPE_IMAGE) {
        mediaFile = new File(mediaStorageDir.getPath() + File.separator + "IMG_" + timeStamp + ".jpg");
    } else if (type == MEDIA_TYPE_VIDEO) {
        mediaFile = new File(mediaStorageDir.getPath() + File.separator + "VID_" + timeStamp + ".mp4");
    } else {
        return null;
    }

    return mediaFile;
}

//For select picture
public static String getRealPathFromUri(Context context, Uri contentUri) {
    Cursor cursor = null;
    try {
        String[] proj = {MediaStore.Images.Media.DATA};
        cursor = context.getContentResolver().query(contentUri, proj, null, null, null);
        int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        return cursor.getString(column_index);
    } finally {
        if (cursor != null) {
            cursor.close();
        }
    }
}
0

我认为，如果你正在从片段使用意图，并且如果你使用了 getActivity() 请确保你已经将你的片段附加到你的活动中，否则它可能会抛出空指针异常。 因此，在我的情况下，我使用了一个解决方法来获取上下文，你可以使用它

创建一个全局变量 View rootView 并在 OnViewCreated() 方法 中初始化它，然后你可以相应地使用它。

public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode != Activity.RESULT_OK) {
    return;
}

if (requestCode == REQUEST_IMAGE_CAPTURE) {
Log.d(UploadPicturesFragment.class.getSimpleName(),
            "IMAGE URI NOT NULL: " + (mHighQualityImageUri == null));
    try {
        Bitmap bitmap = MediaStore.Images.Media.getBitmap( rootView.getContext().getContentResolver(),
                mHighQualityImageUri);
        DroomUtil.beginCrop(mHighQualityImageUri, rootView.getContext(), this, true, bitmap.getWidth(),
                bitmap.getHeight());
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}}
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