public void showContacts(View v) {

    // Verify that all required contact permissions have been granted.
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION)
            != PackageManager.PERMISSION_GRANTED
|| ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION
 
)
            != PackageManager.PERMISSION_GRANTED
|| ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)
            != PackageManager.PERMISSION_GRANTED
|| ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_PHONE_STATE)
            != PackageManager.PERMISSION_GRANTED
 
) {
        // Contacts permissions have not been granted.
requestContactsPermissions(v);
} else {

        // Contact permissions have been granted. Show the contacts fragment.
initViewsAndEvents();
}
}
private void requestContactsPermissions(View v) {
    // BEGIN_INCLUDE(contacts_permission_request)
if 
 
(ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.ACCESS_COARSE_LOCATION)
            || ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.ACCESS_FINE_LOCATION)
            || ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.WRITE_EXTERNAL_STORAGE)
            || ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.READ_PHONE_STATE)
            ) {

        // Display a SnackBar with an explanation and a button to trigger the request.
Snackbar.make(v, "permission_contacts_rationale",
Snackbar.LENGTH_INDEFINITE)
                .setAction("ok", new View.OnClickListener() {
                    @Override
public void onClick(View view) {
                        ActivityCompat.requestPermissions(LocationActivity.this,new String[]{Manifest.permission.ACCESS_COARSE_LOCATION,
Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.READ_PHONE_STATE}, REQUEST_CONTACTS);
}
                })
                .show();
} else {
        // Contact permissions have not been granted yet. Request them directly.
ActivityCompat.requestPermissions(LocationActivity.this,new String[]{Manifest.permission.ACCESS_COARSE_LOCATION,
Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.READ_PHONE_STATE}, REQUEST_CONTACTS);
}
    // END_INCLUDE(contacts_permission_request)
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {

    if (requestCode==REQUEST_CONTACTS){
        if (PermissionUtil.verifyPermissions(grantResults)) {

            initViewsAndEvents();
}
    }else{
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
}
}
這個方法可以實現相容性