Question

我在Android应用中从图库加载图片时遇到问题。我有一些代码可以在模拟器中选择一个图像。当我做出选择时，抛出并捕获异常，意味着图像没有加载，但我不确定如何诊断正在发生的事情。

这是我的java代码文件：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    galleryImage = (ImageView) findViewById(R.id.imageView);
    pick_btn = (Button)findViewById(R.id.button);
    pick_btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent i = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
            startActivityForResult(i,RESULT_LOAD_IMG);
        }
    });
}

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

        if (requestCode == RESULT_LOAD_IMG && resultCode == RESULT_OK && null != data) {
            Uri selectedImage = data.getData();
            String[] filePathColumn = {MediaStore.Images.Media.DATA};

            Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
            Log.i("Image Column Index..", "hoiiii");
            assert cursor != null;
            cursor.moveToFirst();

            int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
            picturePath = cursor.getString(columnIndex);
            cursor.close();

            galleryImage.setImageBitmap(BitmapFactory.decodeFile(picturePath));
        }
    }catch (Exception e)
    {
        Toast.makeText(getApplicationContext(),"You haven't picked any image",Toast.LENGTH_LONG).show();
    }
}

}

Answer 1

您需要先询问WRITE_EXTERNAL_STORAGE的运行时权限你从gallary中选择图像。

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

声明权限和请求代码

private static final String[] REQUEST_PERMISSIONS = new String[]{
            Manifest.permission.WRITE_EXTERNAL_STORAGE
    };
    private static final int REQUEST_PERMISSION_CODE = 007;
//check if permissions are needed

       if (!checkPermission()) {
            requestPermission();
        } else {
//open gallary and pick image      
  }



private boolean checkPermission () {
            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
                return true;
            }
            for (String permission : REQUEST_PERMISSIONS) {
                if (ActivityCompat.checkSelfPermission(this, permission) != PackageManager.PERMISSION_GRANTED) {
                    return false;
                }
            }


            return true;
        }
    private void requestPermission () {
        ActivityCompat.requestPermissions(this, REQUEST_PERMISSIONS, REQUEST_PERMISSION_CODE);
    }

    @Override
    public void onRequestPermissionsResult ( int requestCode, @NonNull String[] permissions,
    @NonNull int[] grantResults){
        if (requestCode == REQUEST_PERMISSION_CODE) {
            if (grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    //open gallary and pick image
            }
        }
    }

Answer 2

请检查清单文件中的用户权限：

  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Answer 3

这是我编辑的代码：

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

        try
        {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)
            {
                if (!Settings.System.canWrite(this) && (requestCode == RESULT_LOAD_IMG && resultCode == RESULT_OK && null != data))
                {
                    requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE,
                            Manifest.permission.READ_EXTERNAL_STORAGE}, 2909);

                    Uri selectedImage = data.getData();
                    String[] filePathColumn = {MediaStore.Images.Media.DATA};

                    Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
                    assert cursor != null;
                    cursor.moveToFirst();

                    int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
                    picturePath = cursor.getString(columnIndex);
                    cursor.close();

                    imageView.setImageBitmap(BitmapFactory.decodeFile(picturePath));
                }
            }
        } catch (Exception e)
        {
            Toast.makeText(getApplicationContext(), "Something went wrong", Toast.LENGTH_LONG).show();
        }
    }

无法将Image加载到ImageView中

3 个答案: