android-studio - Android 9.+ API 29 :/storage/emulated/0/Pictures/myPic. png 打开失败:EACCES(权限被拒绝)

Question

我正在使用 Android Virtual Device (AVD) Nexus 7 (2012) API 29 在 Android Studio 3.4.1 上尝试一个非常基本的相机应用程序的源代码。我在模拟器中用相机拍了一张照片，并试图将其保存为/storage/emulated/0/Pictures/myPic.png，但有一个异常/storage/emulated/0/Pictures/myPic.png 打开失败:EACCES(权限被拒绝)。我已经尝试了所有在线提供的建议，例如:

在 AndroidManifest.xml 中，我添加了:

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

在 MainActivity.java 中，我添加了以下运行时权限检查和请求代码:

public class MainActivity extends Activity {

    private static final int REQUEST_EXTERNAL_STORAGE = 1;
    private static String[] PERMISSIONS_STORAGE = {
            Manifest.permission.READ_EXTERNAL_STORAGE,
            Manifest.permission.WRITE_EXTERNAL_STORAGE
    };

    public static void verifyStoragePermissions(Activity activity) {
        int permission = ActivityCompat.checkSelfPermission(activity, Manifest.permission.WRITE_EXTERNAL_STORAGE);

        boolean checkPermission = (permission == PackageManager.PERMISSION_GRANTED);

        Toast toastPermission = Toast.makeText(activity,
                "Is permission granted? " + checkPermission,
                Toast.LENGTH_SHORT);
        LinearLayout toastLayoutPermission = (LinearLayout) toastPermission.getView();
        TextView toastTVPermission = (TextView) toastLayoutPermission.getChildAt(0);
        toastTVPermission.setTextSize(30);
        toastPermission.show();


        if (permission != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(
                    activity,
                    PERMISSIONS_STORAGE,
                    REQUEST_EXTERNAL_STORAGE
            );
        }
    }

然后我在 onCreate 和就在我想保存图片之前检查并请求权限，如下所示:

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        verifyStoragePermissions(this);


......


private void saveImageToFile(File file)
    {
        if (mCameraBitmap != null)
        {
            FileOutputStream outStream = null;

            verifyStoragePermissions(this);

            try
            {
                outStream = new FileOutputStream(file);

                ...

            }
            catch (Exception e)
            {
                Toast toastException = Toast.makeText(MainActivity.this,
                        "Exception: " + e.getMessage(),
                        Toast.LENGTH_SHORT);
                LinearLayout toastLayoutException = (LinearLayout) toastException.getView();
                TextView toastTVException = (TextView) toastLayoutException.getChildAt(0);
                toastTVException.setTextSize(30);
                toastException.show();
            }

...

我还在模拟器中手动检查了存储权限，以确保允许访问存储。

但是，没有任何建议有效!

代码抛出了一个异常

/storage/emulated/0/Pictures/myPic.png 打开失败:EACCES(权限被拒绝)

当它到达线

outStream = new FileOutputStream(file);

有什么想法可以进一步解决这个问题吗？非常感谢。

Answer 1

添加 android:requestLegacyExternalStorage="true"到 Android Manifest 为我工作的 Android 29

<application
    android:name=".MyApplication"
    android:allowBackup="true"
    android:requestLegacyExternalStorage="true" ...