Android 6.0 Marshmallow.无法写入SD卡

Question

我有一个使用外部存储来存储照片的应用程序.根据需要,在其清单中,请求以下权限

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

它使用以下内容来检索所需的目录

File sdDir = Environment
            .getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);

SimpleDateFormat dateFormat = new SimpleDateFormat("MM-dd", Locale.US);
String date = dateFormat.format(new Date());
storageDir = new File(sdDir, getResources().getString(
            R.string.storagedir)
            + "-" + date);

// Create directory, error handling
if (!storageDir.exists() && !storageDir.mkdirs()) {
 ... fails here

该应用程序适用于Android 5.1至2.3; 它已在Google Play上播放了一年多.

在将我的一个测试手机(Android One)升级到6之后,它现在在尝试创建必需目录时返回错误,"/ sdcard/Pictures/myapp-yy-mm".

SD卡配置为"便携式存储".我已经格式化了SD卡.我已经取代了它.我重新启动了.一切都无济于事.

此外,内置的Android屏幕截图功能(通过电源+低音量)失败"由于存储空间有限,或者应用程序或您的组织不允许".

有任何想法吗？

Answer 1

我遇到了同样的问题.Android中有两种类型的权限:

• 危险(访问联系人,写入外部存储...)
• 正常

Android会自动批准普通权限,而Android用户需要批准危险权限.

以下是在Android 6.0中获取危险权限的策略

1. 检查您是否已获得许可
2. 如果您的应用已获得许可,请继续正常运行.
3. 如果您的应用尚未获得许可,请要求用户批准
4. 在onRequestPermissionsResult中收听用户批准

这是我的情况:我需要写入外部存储.

首先,我检查一下我是否有权限:

...
private static final int REQUEST_WRITE_STORAGE = 112;
...
boolean hasPermission = (ContextCompat.checkSelfPermission(activity,
            Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED);
if (!hasPermission) {
    ActivityCompat.requestPermissions(parentActivity,
                new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                REQUEST_WRITE_STORAGE);
}

然后检查用户的批准:

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    switch (requestCode)
    {
        case REQUEST_WRITE_STORAGE: {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED)
            {
                //reload my activity with permission granted or use the features what required the permission
            } else
            {
                Toast.makeText(parentActivity, "The app was not allowed to write to your storage. Hence, it cannot function properly. Please consider granting it this permission", Toast.LENGTH_LONG).show();
            }
        }
    }

}

您可以在此处详细了解新的权限模型:https://developer.android.com/training/permissions/requesting.html

Answer 2

首先,我将在Android M及更高版本中为您提供危险许可列表

然后举例说明如何在Android M及更高版本中请求权限.

我问用户WRITE_EXTERNAL_STORAGE权限.

首先在android menifest文件中添加权限

步骤1声明请求代码

 private static String TAG = "PermissionDemo";
 private static final int REQUEST_WRITE_STORAGE = 112; 

步骤2当您要求用户许可时,请添加此代码

 //ask for the permission in android M
    int permission = ContextCompat.checkSelfPermission(this,
            Manifest.permission.WRITE_EXTERNAL_STORAGE);

    if (permission != PackageManager.PERMISSION_GRANTED) {
        Log.i(TAG, "Permission to record denied");

        if (ActivityCompat.shouldShowRequestPermissionRationale(this,
                Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setMessage("Permission to access the SD-CARD is required for this app to Download PDF.")
                    .setTitle("Permission required");

            builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {

                public void onClick(DialogInterface dialog, int id) {
                    Log.i(TAG, "Clicked");
                    makeRequest();
                }
            });

            AlertDialog dialog = builder.create();
            dialog.show();

        } else {
            makeRequest();
        }
    }

    protected void makeRequest() {
        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                REQUEST_WRITE_STORAGE);
    }

步骤3为Request添加覆盖方法

 @Override
public void onRequestPermissionsResult(int requestCode,
                                       String permissions[], int[] grantResults) {
    switch (requestCode) {
        case REQUEST_WRITE_STORAGE: {

            if (grantResults.length == 0
                    || grantResults[0] !=
                    PackageManager.PERMISSION_GRANTED) {

                Log.i(TAG, "Permission has been denied by user");

            } else {

                Log.i(TAG, "Permission has been granted by user");

            }
            return;
        }
    }
}

注意:不要忘记在menifest文件中添加权限

BELOW最好的例子具有多项权限PLUS覆盖所有情景

我添加了评论,因此您可以轻松理解.

import android.Manifest;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.provider.Settings;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import com.production.hometech.busycoder.R;

import java.util.ArrayList;

public class PermissionInActivity extends AppCompatActivity implements View.OnClickListener {

    private static final int REQUEST_PERMISSION_SETTING = 99;
    private Button bt_camera;
    private static final String[] PARAMS_TAKE_PHOTO = {
            Manifest.permission.CAMERA,
            Manifest.permission.WRITE_EXTERNAL_STORAGE
    };
    private static final int RESULT_PARAMS_TAKE_PHOTO = 11;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_permission_in);

        bt_camera = (Button) findViewById(R.id.bt_camera);

        bt_camera.setOnClickListener(this);

    }

    @Override
    public void onClick(View view) {

        switch (view.getId()) {

            case R.id.bt_camera:

                takePhoto();

                break;

        }
    }


    /**
     * shouldShowRequestPermissionRationale() = This will return true if the user had previously declined to grant you permission
     * NOTE :  that ActivityCompat also has a backwards-compatible implementation of
     * shouldShowRequestPermissionRationale(), so you can avoid your own API level
     * checks.
     * <p>
     * shouldShowRequestPermissionRationale() =  returns false if the user declined the permission and checked the checkbox to ask you to stop pestering the
     * user.
     * <p>
     * requestPermissions() = request for the permisssiion
     */
    private void takePhoto() {

        if (canTakePhoto()) {

            Toast.makeText(this, "You can take PHOTO", Toast.LENGTH_SHORT).show();

        } else if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.CAMERA) || ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {

            Toast.makeText(this, "You should give permission", Toast.LENGTH_SHORT).show();
            ActivityCompat.requestPermissions(this, netPermisssion(PARAMS_TAKE_PHOTO), RESULT_PARAMS_TAKE_PHOTO);

        } else {
            ActivityCompat.requestPermissions(this, netPermisssion(PARAMS_TAKE_PHOTO), RESULT_PARAMS_TAKE_PHOTO);
        }

    }

    //  This method return  permission denied String[] so we can request again
    private String[] netPermisssion(String[] wantedPermissions) {
        ArrayList<String> result = new ArrayList<>();

        for (String permission : wantedPermissions) {
            if (!hasPermission(permission)) {
                result.add(permission);
            }
        }

        return (result.toArray(new String[result.size()]));

    }

    private boolean canTakePhoto() {
        return (hasPermission(Manifest.permission.CAMERA) && hasPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE));
    }

    /**
     * checkSelfPermission() = you can check if you have been granted a runtime permission or not
     * ex = ContextCompat.checkSelfPermission(this,permissionString)== PackageManager.PERMISSION_GRANTED
     * <p>
     * ContextCompat offers a backwards-compatible implementation of checkSelfPermission(), ActivityCompat offers a backwards-compatible
     * implementation of requestPermissions() that you can use.
     *
     * @param permissionString
     * @return
     */
    private boolean hasPermission(String permissionString) {
        return (ContextCompat.checkSelfPermission(this, permissionString) == PackageManager.PERMISSION_GRANTED);
    }

    /**
     * requestPermissions() action goes to onRequestPermissionsResult() whether user can GARNT or DENIED those permisssions
     *
     * @param requestCode
     * @param permissions
     * @param grantResults
     */
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);

        if (requestCode == RESULT_PARAMS_TAKE_PHOTO) {

            if (canTakePhoto()) {

                Toast.makeText(this, "You can take picture", Toast.LENGTH_SHORT).show();

            } else if (!(ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.CAMERA) || ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE))) {


                final AlertDialog.Builder settingDialog = new AlertDialog.Builder(PermissionInActivity.this);
                settingDialog.setTitle("Permissioin");
                settingDialog.setMessage("Now you need to enable permisssion from the setting because without permission this app won't run properly \n\n  goto -> setting -> appInfo");
                settingDialog.setCancelable(false);

                settingDialog.setPositiveButton("Setting", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {

                        dialogInterface.cancel();

                        Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
                        Uri uri = Uri.fromParts("package", getPackageName(), null);
                        intent.setData(uri);
                        startActivityForResult(intent, REQUEST_PERMISSION_SETTING);
                        Toast.makeText(getBaseContext(), "Go to Permissions to Grant all permission ENABLE", Toast.LENGTH_LONG).show();

                    }
                });
                settingDialog.show();

                Toast.makeText(this, "You need to grant permission from setting", Toast.LENGTH_SHORT).show();

            }

        }

    }

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

        if (requestCode == REQUEST_PERMISSION_SETTING) {

            if (canTakePhoto()) {

                Toast.makeText(this, "You can take PHOTO", Toast.LENGTH_SHORT).show();

            }

        }

    }


}

配置更改的特殊情况

当我们的权限对话框在前台时,用户可能会旋转设备或以其他方式触发配置更改.由于我们的活动在该对话框后面仍然可见,因此我们会被销毁并重新创建...但我们不想再次重新提升权限对话框.

这就是为什么我们有一个名为isInPermission的布尔值,它跟踪我们是否处于请求权限的中间.我们坚持这个价值 onSaveInstanceState():

@Override
protected void onSaveInstanceState(Bundle outState) {
  super.onSaveInstanceState(outState);
  outState.putBoolean(STATE_IN_PERMISSION, isInPermission);
}

我们恢复它onCreate().如果我们没有保留所有所需的权限,但是isInPermission为true,我们就会跳过请求权限,因为我们已经在执行此操作.

Answer 3

Android改变了Android 6.0权限的使用方式,这就是导致错误的原因.您必须实际请求并检查用户是否授予了使用权限.因此,清单文件中的权限仅适用于21以下的api.请在此链接中查看api23中请求权限的代码片段http://android-developers.blogspot.nl/2015/09/google-play-services-81-和机器人-60.html？m = 1的

码:-

If (ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.READ_EXTERNAL_STORAGE) !=
                PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, STORAGE_PERMISSION_RC);
            return;
        }`


` @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == STORAGE_PERMISSION_RC) {
            if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                //permission granted  start reading
            } else {
                Toast.makeText(this, "No permission to read external storage.", Toast.LENGTH_SHORT).show();
            }
        }
    }
}

Answer 4

也许您不能在项目中使用生成代码中的清单类.因此,您可以使用android sdk"android.Manifest.permission.WRITE_EXTERNAL_STORAGE"中的清单类.但在Marsmallow版本中有2个权限必须授予存储类别中的WRITE和READ EXTERNAL STORAGE.看到我的程序,我的程序将请求权限,直到用户选择yes并在授予权限后执行某些操作.

            if (Build.VERSION.SDK_INT >= 23) {
                if (ContextCompat.checkSelfPermission(LoginActivity.this, android.Manifest.permission.WRITE_EXTERNAL_STORAGE)
                        != PackageManager.PERMISSION_GRANTED || ContextCompat.checkSelfPermission(LoginActivity.this, android.Manifest.permission.READ_EXTERNAL_STORAGE)
                        != PackageManager.PERMISSION_GRANTED) {
                    ActivityCompat.requestPermissions(LoginActivity.this,
                            new String[]{android.Manifest.permission.WRITE_EXTERNAL_STORAGE, android.Manifest.permission.READ_EXTERNAL_STORAGE},
                            1);
                } else {
                    //do something
                }
            } else {
                    //do something
            }