1.引入说明

• 背景：Android6.0开始蓝牙需要位置权限才能扫描到设备；位置权限属于敏感权限，需要动态申请，用户授权；

2.官方权限说明使用

• 1.判断权限是否被授予，没有则申请

 int checkCameraPermission =  ContextCompat.checkSelfPermission(mContext, Manifest.permission.CAMERA);

    if (checkCameraPermission != PackageManager.PERMISSION_GRANTED) {
    /*
        用户未授权,谷歌推荐标准流程
    */
    if (ActivityCompat.shouldShowRequestPermissionRationale(getActivity(),Manifest.permission.CAMERA)) {
        //Show an expanation to the user asynchronously.说明请求原因,之前被用户拒绝过
        showRequestPermissionRationale("请授权", new DialogInterface.OnClickListener(){
            @Override 
            public void onClick(DialogInterface dialog, int which) {
                //点击确定时再次申请权限
                requestPermissions(new String[] { Manifest.permission.CAMERA},REQUEST_PERMISSION_CAMERA);
                    }
                });
    } else {
        //第一次申请时，请求授权
        requestPermissions(new String[] { Manifest.permission.CAMERA },REQUEST_PERMISSION_CAMERA);
    }
}

注意：shouldShowRequestPermissionRationale()方法，用户在设置里取消了授权, 或之前拒绝请求过 时返回true。第一次询问 , check了不再询问 时返回false。

• 2.onRequestPermissionsResult方法中接受返回值并进行判断：

@Override 
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,@NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    switch (requestCode) {
        case REQUEST_PERMISSION_CAMERA:
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                // permission was granted,
                LogUtil.d("Camera Granted");
            } else {
                // permission denied
                LogUtil.d("Camera Denied");
                Toast.makeText(mContext, "未授权", Toast.LENGTH_SHORT).show();
                }
            }
            break;
    }
}

3.封装权限开源介绍

• easypermissions

贴一下使用sample代码，下载使用代码程序运行一遍看下流程，然后根据注解使用查看即可：

public class MainActivity extends AppCompatActivity implements EasyPermissions.PermissionCallbacks,
                                                               EasyPermissions.RationaleCallbacks{

    private static final String TAG = "MainActivity";
    private static final String[] LOCATION_AND_CONTACTS =
            {Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.READ_CONTACTS};

    private static final int RC_CAMERA_PERM = 123;
    private static final int RC_LOCATION_CONTACTS_PERM = 124;

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

        // Button click listener that will request one permission.
        findViewById(R.id.button_camera).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                cameraTask();
            }
        });

        // Button click listener that will request two permissions.
        findViewById(R.id.button_location_and_contacts).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                locationAndContactsTask();
            }
        });
    }

    private boolean hasCameraPermission() {
        return EasyPermissions.hasPermissions(this, Manifest.permission.CAMERA);
    }

    private boolean hasLocationAndContactsPermissions() {
        return EasyPermissions.hasPermissions(this, LOCATION_AND_CONTACTS);
    }

    private boolean hasSmsPermission() {
        return EasyPermissions.hasPermissions(this, Manifest.permission.READ_SMS);
    }

    private boolean hasStoragePermission() {
        return EasyPermissions.hasPermissions(this, Manifest.permission.WRITE_EXTERNAL_STORAGE);
    }

    @AfterPermissionGranted(RC_CAMERA_PERM)
    public void cameraTask() {
        if (hasCameraPermission()) {
            // Have permission, do the thing!
            Toast.makeText(this, "TODO: Camera things", Toast.LENGTH_LONG).show();
        } else {
            // Ask for one permission
            EasyPermissions.requestPermissions(
                    this,
                    getString(R.string.rationale_camera),
                    RC_CAMERA_PERM,
                    Manifest.permission.CAMERA);
        }
    }

    @AfterPermissionGranted(RC_LOCATION_CONTACTS_PERM)
    public void locationAndContactsTask() {
        if (hasLocationAndContactsPermissions()) {
            // Have permissions, do the thing!
            Toast.makeText(this, "TODO: Location and Contacts things", Toast.LENGTH_LONG).show();
        } else {
            // Ask for both permissions
            EasyPermissions.requestPermissions(
                    this,
                    getString(R.string.rationale_location_contacts),
                    RC_LOCATION_CONTACTS_PERM,
                    LOCATION_AND_CONTACTS);
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode,
                                           @NonNull String[] permissions,
                                           @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);

        // EasyPermissions handles the request result.
        EasyPermissions.onRequestPermissionsResult(requestCode, permissions, grantResults, this);
    }

    @Override
    public void onPermissionsGranted(int requestCode, @NonNull List<String> perms) {
        Log.d(TAG, "onPermissionsGranted:" + requestCode + ":" + perms.size());
    }

    @Override
    public void onPermissionsDenied(int requestCode, @NonNull List<String> perms) {
        Log.d(TAG, "onPermissionsDenied:" + requestCode + ":" + perms.size());

        // (Optional) Check whether the user denied any permissions and checked "NEVER ASK AGAIN."
        // This will display a dialog directing them to enable the permission in app settings.
        if (EasyPermissions.somePermissionPermanentlyDenied(this, perms)) {
            new AppSettingsDialog.Builder(this).build().show();
        }
    }

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

        if (requestCode == AppSettingsDialog.DEFAULT_SETTINGS_REQ_CODE) {
            String yes = getString(R.string.yes);
            String no = getString(R.string.no);

            // Do something after user returned from app settings screen, like showing a Toast.
            Toast.makeText(
                    this,
                    getString(R.string.returned_from_app_settings_to_activity,
                              hasCameraPermission() ? yes : no,
                              hasLocationAndContactsPermissions() ? yes : no,
                              hasSmsPermission() ? yes : no),
                    Toast.LENGTH_LONG)
                    .show();
        }
    }

    @Override
    public void onRationaleAccepted(int requestCode) {
        Log.d(TAG, "onRationaleAccepted:" + requestCode);
    }

    @Override
    public void onRationaleDenied(int requestCode) {
        Log.d(TAG, "onRationaleDenied:" + requestCode);
    }
}