Question

我遇到有关BitMapFactory.decodeFile的问题。

在我的应用中，我希望用户能够从他/她的设备中选择图像或拍照。然后必须在ImageView

中显示

以下是代码段：

Uri selectedImage = data.getData();
String[] filePathColumn = {MediaStore.Images.Media.DATA};
Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
                    cursor.moveToFirst();
                    int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
                    String picturePath = cursor.getString(columnIndex);
                    cursor.close();
                    MyImage image = new MyImage();
                    image.setTitle("Test");
                    image.setDescription("test choose a photo from gallery and add it to " + "list view");
                    image.setDatetime(System.currentTimeMillis());
                    image.setPath(picturePath);

我得到了这个例外：

BitmapFactory: Unable to decode stream: java.io.FileNotFoundException: /storage/emulated/0/WhatsApp/Media/WhatsApp Images/IMG-20170302-WA0012.jpg: open failed: EACCES (Permission denied)

如何解决它。请帮助我。谢谢。

Answer 1

它的权限问题，您需要在清单中为外部读取存储添加权限，然后才能使用它，如果您使用的是6.0以上，则需要使用Easy权限。

写作：

colors=np.random.randint(len(dist))
cmap=plt.cm.viridis
plt.scatter(dist,corr,c=colors,cmap=cmap)
plt.colorbar()
plt.show()

阅读：

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

6.0以上：

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

Answer 2

启动CAMERA意图时，您已经要求READ-EXTERNAL存储的运行时权限：

final int MyVersion = Build.VERSION.SDK_INT;
        if (MyVersion > Build.VERSION_CODES.LOLLIPOP_MR1) {
            if (!checkIfAlreadyhavePermission()) {
                ActivityCompat.requestPermissions(new String[]{android.Manifest.permission.READ_EXTERNAL_STORAGE}, 1);
            } else {
               startYourCameraIntent();
            }
        }

checkIfAlreadyhavePermission（）方法：

private boolean checkIfAlreadyhavePermission() {
        int result = ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.WRITE_EXTERNAL_STORAGE);
        return result == PackageManager.PERMISSION_GRANTED;
    }

处理权限对话框＆＃34;允许＆＃34;和＆＃34;拒绝＆＃34; onRequestPermission（）中的按钮操作：

@Override
        public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
            super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        switch (requestCode) {
            case 1: {
                if (grantResults.length > 0
                        && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                   startYourCameraIntent();

                } else {
                    Toast.makeText(getActivity(), "Please give your permission.", Toast.LENGTH_LONG).show();
                }
                break;
            }
        }
    }

并将其添加到您的Manifest应用程序代码中：

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

Answer 3

将此添加到您的MainActivity.java文件中

6.0或更高版本的操作系统：

    if(ActivityCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.READ_EXTERNAL_STORAGE)!=PackageManager.PERMISSION_GRANTED){
        ActivityCompat.requestPermissions(MainActivity.this,new String[]{
                Manifest.permission.READ_EXTERNAL_STORAGE
        },1);

    }

 @Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if(requestCode==1){
        if(grantResults[0]==PackageManager.PERMISSION_GRANTED){

        }
        else{
            Toast.makeText(getApplicationContext(), "Permission Denied", Toast.LENGTH_LONG).show();
        }
    }
}

BitmapFactory：无法解码流：java.io.FileNotFoundException

3 个答案: