那些遇到过的问题

android:相机无法在棉花糖中打开

Chi*_*oni 18 android android-camera android-6.0-marshmallow

所以,我有以下代码打开相机,捕获图像并将其保存在SDCard上.

public void getPhotoFromCamera() {
    Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    File mediaStorageDir = new File(
            Environment.getExternalStorageDirectory()
                    + File.separator
                    + getString(R.string.directory_name_corp_chat)
                    + File.separator
                    + getString(R.string.directory_name_temp)
    );

    if (!mediaStorageDir.exists()) {
        mediaStorageDir.mkdirs();
    }

    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss",
            Locale.getDefault()).format(new Date());
    try {
        mediaFile = File.createTempFile(
                "TEMP_FULL_IMG_" + timeStamp,
                ".jpg",
                mediaStorageDir
        );
        takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(mediaFile));
        startActivityForResult(takePictureIntent, PICK_FROM_CAMERA);
    } catch (IOException e) {
        e.printStackTrace();
    }
}

private void performCrop(Uri picUri) {
    try {
        Intent cropIntent = new Intent("com.android.camera.action.CROP");
        cropIntent.setDataAndType(picUri, "image/*");
        cropIntent.putExtra("crop", "true");
        cropIntent.putExtra("aspectX", 1);
        cropIntent.putExtra("aspectY", 1);
        cropIntent.putExtra("outputX", 128);
        cropIntent.putExtra("outputY", 128);
        // retrieve data on return
        cropIntent.putExtra("return-data", true);

        File mediaStorageDir = new File(
                Environment.getExternalStorageDirectory()
                        + File.separator
                        + getString(R.string.directory_name_corp_chat)
                        + File.separator
                        + getString(R.string.directory_name_temp)
        );

        if (!mediaStorageDir.exists()) {
            mediaStorageDir.mkdirs();
        }

        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss",
                Locale.getDefault()).format(new Date());
        try {
            croppedFile = File.createTempFile(
                    "TEMP_CROPPED_IMG_" + timeStamp,
                    ".jpg",
                    mediaStorageDir
            );
            cropIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(croppedFile));
            startActivityForResult(cropIntent, PIC_CROP);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    // respond to users whose devices do not support the crop action
    catch (ActivityNotFoundException anfe) {
        // display an error message
        String errorMessage = "Whoops - your device doesn't support the crop action!";
        Toast toast = Toast.makeText(this, errorMessage, Toast.LENGTH_SHORT);
        toast.show();
    }
}

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

    if (requestCode == PICK_FROM_CAMERA) {
        if (resultCode == RESULT_OK) {
            performCrop(Uri.fromFile(mediaFile));
        } else {
            Log.i("Camera", "result cancel. Hence, deleting file: " + mediaFile.getPath());
            Log.i("File deleted ", mediaFile.delete() + "");
        }
    }

    if (requestCode == PICK_FROM_GALLERY) {
        if (resultCode == RESULT_OK) {
            performCrop(data.getData());
        } else {
            Log.i("Gallery", "result cancel");
        }
    }

    if (requestCode == PIC_CROP) {
        if (resultCode == RESULT_OK) {
            imageView.setImageBitmap(BitmapFactory.decodeFile(croppedFile.getAbsolutePath()));
            if (mediaFile != null) {
                Log.i("Camera", "result cancel. Hence, deleting file: " + mediaFile.getPath());
                Log.i("File deleted ", mediaFile.delete() + "");
            }
        } else {
            if (croppedFile != null) {
                Log.i("Camera", "result cancel. Hence, deleting file: " + croppedFile.getPath());
                Log.i("File deleted ", croppedFile.delete() + "");
            }
            if (mediaFile != null) {
                Log.i("Camera", "result cancel. Hence, deleting file: " + mediaFile.getPath());
                Log.i("File deleted ", mediaFile.delete() + "");
            }
        }
    }
}
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在Android 6.0下,一切都如预期的那样完美.但它在Android 6.0 Marshmallow上不起作用.事实上,它甚至没有打开相机:(

我不知道是否必须为棉花糖做些特别的事情.我也没有收到任何错误,我可以在这里发布.请帮帮我.

谢谢.

Chi*_*oni 34

所以,我完成了如下任务:

对于Checking权限,我创建了一个单独的类,如下所示:

public class MarshMallowPermission {

    public static final int RECORD_PERMISSION_REQUEST_CODE = 1;
    public static final int EXTERNAL_STORAGE_PERMISSION_REQUEST_CODE = 2;
    public static final int CAMERA_PERMISSION_REQUEST_CODE = 3;
    Activity activity;

    public MarshMallowPermission(Activity activity) {
        this.activity = activity;
    }

    public boolean checkPermissionForRecord(){
        int result = ContextCompat.checkSelfPermission(activity, Manifest.permission.RECORD_AUDIO);
        if (result == PackageManager.PERMISSION_GRANTED){
            return true;
        } else {
            return false;
        }
    }

    public boolean checkPermissionForExternalStorage(){
        int result = ContextCompat.checkSelfPermission(activity, Manifest.permission.WRITE_EXTERNAL_STORAGE);
        if (result == PackageManager.PERMISSION_GRANTED){
            return true;
        } else {
            return false;
        }
    }

    public boolean checkPermissionForCamera(){
        int result = ContextCompat.checkSelfPermission(activity, Manifest.permission.CAMERA);
        if (result == PackageManager.PERMISSION_GRANTED){
            return true;
        } else {
            return false;
        }
    }

    public void requestPermissionForRecord(){
        if (ActivityCompat.shouldShowRequestPermissionRationale(activity, Manifest.permission.RECORD_AUDIO)){
           Toast.makeText(activity, "Microphone permission needed for recording. Please allow in App Settings for additional functionality.", Toast.LENGTH_LONG).show();
        } else {
            ActivityCompat.requestPermissions(activity,new String[]{Manifest.permission.RECORD_AUDIO},RECORD_PERMISSION_REQUEST_CODE);
        }
    }

    public void requestPermissionForExternalStorage(){
        if (ActivityCompat.shouldShowRequestPermissionRationale(activity, Manifest.permission.WRITE_EXTERNAL_STORAGE)){
            Toast.makeText(activity, "External Storage permission needed. Please allow in App Settings for additional functionality.", Toast.LENGTH_LONG).show();
        } else {
            ActivityCompat.requestPermissions(activity,new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},EXTERNAL_STORAGE_PERMISSION_REQUEST_CODE);
        }
    }

    public void requestPermissionForCamera(){
        if (ActivityCompat.shouldShowRequestPermissionRationale(activity, Manifest.permission.CAMERA)){
            Toast.makeText(activity, "Camera permission needed. Please allow in App Settings for additional functionality.", Toast.LENGTH_LONG).show();
        } else {
            ActivityCompat.requestPermissions(activity,new String[]{Manifest.permission.CAMERA},CAMERA_PERMISSION_REQUEST_CODE);
        }
    }
}
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然后,获得 

...
MarshMallowPermission marshMallowPermission = new MarshMallowPermission(this);
...

public void getPhotoFromCamera() {

    if (!marshMallowPermission.checkPermissionForCamera()) {
        marshMallowPermission.requestPermissionForCamera();
    } else {
        if (!marshMallowPermission.checkPermissionForExternalStorage()) {
            marshMallowPermission.requestPermissionForExternalStorage();
        } else {
            Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            File mediaStorageDir = new File(
                    Environment.getExternalStorageDirectory()
                            + File.separator
                            + getString(R.string.directory_name_corp_chat)
                            + File.separator
                            + getString(R.string.directory_name_images)
            );

            if (!mediaStorageDir.exists()) {
                mediaStorageDir.mkdirs();
            }

            String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss",
                    Locale.getDefault()).format(new Date());
            try {
                mediaFile = File.createTempFile(
                        "IMG_" + timeStamp,  /* prefix */
                        ".jpg",         /* suffix */
                        mediaStorageDir      /* directory */
                );
                takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(mediaFile));
                startActivityForResult(takePictureIntent, PICK_FROM_CAMERA);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}
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  • @ChintanSoni:这是怎么回事？假设第一次没有授予权限,它继续if if语句if(!marshMallowPermission.checkPermissionForCamera())返回false然后请求权限,代码将在此处停止.代码的其他部分将不会被执行,因为它返回在其他部分. (2认同)

Mat*_*ini 7

引用developers.android.com:

从Android 6.0(API级别23)开始,用户在应用程序运行时向应用程序授予权限,而不是在安装应用程序时.此方法简化了应用安装过程,因为用户在安装或更新应用时无需授予权限.它还使用户可以更好地控制应用程序的功能; 例如,用户可以选择让相机应用程序访问相机,但不能访问设备位置.用户可以通过转到应用程序的"设置"屏幕随时撤消权限.

系统权限分为正常和危险两类:

  • 普通权限不会直接冒使用户隐私的风险.如果您的应用在其清单中列出了正常权限,系统会自动授予权限.

  • 危险权限可以让应用程序访问用户的机密数据.如果您的应用在其清单中列出了正常权限,系统会自动授予权限.如果您列出了危险权限,则用户必须明确批准您的应用.

WRITE_EXTERNAL_STORAGE在危险类别,因为这个原因,你需要调用之前请求允许用户mediaStorageDir.mkdirs()或File.createTempFile否则,你的程序与此异常崩溃:

W/System.err: java.io.IOException: open failed: EACCES (Permission denied)
W/System.err:     at java.io.File.createNewFile(File.java:939)
W/System.err:     at java.io.File.createTempFile(File.java:1004)
W/System.err:     at com.example.MainActivity.getPhotoFromCamera(MainActivity.java:98)
W/System.err:     at com.example.MainActivity.onCreate(MainActivity.java:48)
W/System.err:     at android.app.Activity.performCreate(Activity.java:6237)
W/System.err:     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.
W/System.err:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.
W/System.err:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476
W/System.err:     at android.app.ActivityThread.-wrap11(ActivityThread.java)
W/System.err:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:102)
W/System.err:     at android.os.Looper.loop(Looper.java:148)
W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:5417)
W/System.err:     at java.lang.reflect.Method.invoke(Native Method)
W/System.err:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.
W/System.err:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
W/System.err: Caused by: android.system.ErrnoException: open failed: EACCES (Permission 
W/System.err:     at libcore.io.Posix.open(Native Method)
W/System.err:     at libcore.io.BlockGuardOs.open(BlockGuardOs.java:186)
W/System.err:     at java.io.File.createNewFile(File.java:932)
W/System.err:   ... 15 more
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