用户Android M在应用中授予的权限

Question

I want to in my app. if permission already granted not show dialog in android this is my code

@Override
public void onClick(View v) {
    switch (v.getId()){
        case R.id.button:
                requestContactsPermissions();
            break;
        case R.id.button1:
          //  requestCameraPermissions();
            Toast.makeText(mcontext, "Hello", Toast.LENGTH_LONG).show();
            break;
    }

}

private void requestContactsPermissions() {

     boolean requestPermission = PersimissionTest.requestContactsPermissions(this);

    if (requestPermission == true) {
        ActivityCompat.requestPermissions(this, PERMISSIONS_CONTACTS, REQUEST_ID);

    } else {
       ActivityCompat.requestPermissions(this, PERMISSIONS_CONTACTS, REQUEST_ID);

    }

}

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

    if (requestCode == REQUEST_ID) {

        if (PersimissionTest.verifyPermissions(grantResults)) {

            Toast.makeText(mcontext, "Contacts permissions granted.", Toast.LENGTH_LONG).show();

        } else {
            Toast.makeText(mcontext, "Contacts permissions were not granted.", Toast.LENGTH_LONG).show();
        }

    } else {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    }
}

Answer 1

The following code checks if the app has permission to read the user's contacts, and requests the permission if necessary:

// Here, thisActivity is the current activity
if (ContextCompat.checkSelfPermission(thisActivity,
            Manifest.permission.READ_CONTACTS)
    != PackageManager.PERMISSION_GRANTED) {

    // Should we show an explanation?
    if (ActivityCompat.shouldShowRequestPermissionRationale(thisActivity,
        Manifest.permission.READ_CONTACTS)) {

        // Show an expanation to the user *asynchronously* -- don't block
        // this thread waiting for the user's response! After the user
        // sees the explanation, try again to request the permission.

    } else {

        // No explanation needed, we can request the permission.

        ActivityCompat.requestPermissions(thisActivity,
            new String[]{Manifest.permission.READ_CONTACTS},
            MY_PERMISSIONS_REQUEST_READ_CONTACTS);

        // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
        // app-defined int constant. The callback method gets the
        // result of the request.
    }
}
else
{
    // Permission already granted ... This is where you can continue your further business logic...
}

And the following is the callback method:

@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
    switch (requestCode) {
        case MY_PERMISSIONS_REQUEST_READ_CONTACTS: {
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0
            && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                // permission was granted, yay! Do the
                // contacts-related task you need to do.

            } else {

                // permission denied, boo! Disable the
                // functionality that depends on this permission.
            }
            return;
        }

        // other 'case' lines to check for other
        // permissions this app might request
    }
}

For detailed explanation visit here (Android Official Page) or here (Tutsplus Tutorial):

Answer 2

Request Permission Like This , if permission already granted than insert contact else it will ask for permission

private void insertDummyContactWrapper(String mStringPhoneContactName, String mStringPhoneContactNumber) {
    boolean hasWriteContactsPermission = ActivityCompat.shouldShowRequestPermissionRationale(this, android.Manifest.permission.WRITE_CONTACTS);
    if (ContextCompat.checkSelfPermission(this, android.Manifest.permission.WRITE_CONTACTS) != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(SwipableHomeActivity.this, new String[]{android.Manifest.permission.WRITE_CONTACTS}, CONSTANTS.MY_PERMISSIONS_REQUEST_WRITE_CONTACTS);
        return;
    }
    //Insert Contact
}

Get Permission Result Like This

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    switch (requestCode) {
        case CONSTANTS.MY_PERMISSIONS_REQUEST_WRITE_CONTACTS:

            if (grantResults != null && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                ReadPhoneContacts(getApplicationContext(), mStringPhoneContactName, mStringPhoneContactNumber);
            } else {
                Toast.makeText(getApplicationContext(), "Permission Denied", Toast.LENGTH_SHORT).show();
            }
            break;
    }
}

Check this i have implemented in your question

 public static boolean requestContactsPermissions(Activity activity) {
    boolean requestPermission;
    if (ContextCompat.checkSelfPermission(activity, android.Manifest.permission.WRITE_CONTACTS) != PackageManager.PERMISSION_GRANTED) {
        requestPermission = true;
    }else{
        requestPermission = false;
    }
    return requestPermission;
}

public static boolean requestCameraPermissions(Activity activity) {
    boolean requestPermission;
    if (ContextCompat.checkSelfPermission(activity, android.Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED){
        requestPermission = true;
    } else {
        requestPermission = false;
    }
    return requestPermission;
}

Change Your Class With This

public class MainActivity extends AppCompatActivity implements
    OnRequestPermissionsResultCallback, OnClickListener{

public static final String TAG = "PermissionActivity";

private View mLayout;
Button mButtonCheckPermission = null;

private static final int REQUEST_CONTACTS = 1;
private static String[] PERMISSIONS_CONTACT = {Manifest.permission.READ_CONTACTS,
        Manifest.permission.WRITE_CONTACTS};

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

    initView();
}

private void initView() {
    mButtonCheckPermission = (Button) findViewById(R.id.button_check_permissions);
    mButtonCheckPermission.setOnClickListener(this);

    mLayout = findViewById(R.id.sample_main_layout);

}

@Override
public void onClick(View v) {

    switch (v.getId()) {
        case R.id.button_check_permissions:
            requestContactsPermissions();
            break;

        default:
            break;
    }

}

private void requestContactsPermissions() {

    boolean requestPermission = PermissionUtil.requestContactsPermissions(this);

    if (requestPermission == true){

        Log.i(TAG,
                "Displaying contacts permission rationale to provide additional context.");

        // Display a SnackBar with an explanation and a button to trigger the request.

        if (ContextCompat.checkSelfPermission(MainActivity.this, android.Manifest.permission.WRITE_CONTACTS) != PackageManager.PERMISSION_GRANTED) {

            Snackbar.make(mLayout, R.string.permission_contacts_rationale,
                    Snackbar.LENGTH_INDEFINITE)
                    .setAction(R.string.ok, new View.OnClickListener() {
                        @Override
                        public void onClick(View view) {
                            ActivityCompat.requestPermissions(MainActivity.this, PERMISSIONS_CONTACT,
                                    REQUEST_CONTACTS);
                        }
                    })
                    .show();
        }else{
            Snackbar.make(mLayout, R.string.permision_available_contacts,
                    Snackbar.LENGTH_LONG)
                    .show();
        }
    }
    else {

        ActivityCompat.requestPermissions(this, PERMISSIONS_CONTACT, REQUEST_CONTACTS);

    }

}

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

    if (requestCode == REQUEST_CONTACTS) {
        Log.i(TAG, "Received response for contact permissions request.");

        // We have requested multiple permissions for contacts, so all of them need to be
        // checked.
        if (PermissionUtil.verifyPermissions(grantResults)) {
            // All required permissions have been granted, display contacts fragment.
            Snackbar.make(mLayout, R.string.permision_available_contacts,
                    Snackbar.LENGTH_LONG)
                    .show();
        } else {
            Log.i(TAG, "Contacts permissions were NOT granted.");
            Snackbar.make(mLayout, R.string.permissions_not_granted,
                    Snackbar.LENGTH_LONG)
                    .show();
        }

    } else {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    }
}}

Answer 3

I have done

@Override
public void onClick(View v) {
    switch (v.getId()){
        case R.id.button:
            if (!checkPermission()) {
                requestContactsPermissions();
            }else{
                Toast.makeText(mcontext, "Permission already granted.", Toast.LENGTH_LONG).show();
            }
            break;
        case R.id.button1:
          //  requestCameraPermissions();
            Toast.makeText(mcontext, "Hello", Toast.LENGTH_LONG).show();


            break;
    }

}

private boolean checkPermission(){
int result = ContextCompat.checkSelfPermission(mcontext, Manifest.permission.READ_CONTACTS);

    if (result == PackageManager.PERMISSION_GRANTED){

        return true;

    } else {

        return false;

    }
}

Answer 4

Try this code ..

  /**
 * this method check permission and return current state of permission need.
 */
private boolean checkPermissions() {
    int permissionState = ActivityCompat.checkSelfPermission(this,
            Manifest.permission.CAMERA);
    return permissionState == PackageManager.PERMISSION_GRANTED;
}

/**
 * this method request to permission asked.
 */
private void requestPermissions() {
    boolean shouldProvideRationale =
            ActivityCompat.shouldShowRequestPermissionRationale(this,
                    Manifest.permission.CAMERA);

    if (shouldProvideRationale) {
        Log.i(TAG, "Displaying permission rationale to provide additional context.");
           } else {
        Log.i(TAG, "Requesting permission");
        // previously and checked "Never ask again".

    }
}
 /**
 * Callback received when a permissions request has been completed.
 */
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
                                       @NonNull int[] grantResults) {
    Log.i(TAG, "onRequestPermissionResult");
    if (requestCode == REQUEST_PERMISSIONS_REQUEST_CODE) {
        if (grantResults.length <= 0) {
            // If user interaction was interrupted, the permission request is cancelled and you
            // receive empty arrays.
            Log.i(TAG, "User interaction was cancelled.");
        } else if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            // Permission was granted. Kick off the process of building and connecting
            // GoogleApiClient.
            buildGoogleApiClient(); // hear your operation method.
             } 
             else {
            // Permission denied.
        }
    }
}

then after check like below code into oncreate method ..

 if (!checkPermissions()) {
        requestPermissions();
    }

    buildGoogleApiClient(); // your method define.