Question

我在权限请求中遇到问题，当我运行我的应用程序时，我得到this message。当我点击＆＃34;给我许可＆＃34;它打开烤面包并要求我允许或拒绝，当我点击允许它将关闭应用程序。然后我应该再次打开它，它将正常工作。当我点击按钮时，有一个允许许可的Toast消息，我的代码中是否有任何错误？
谢谢

IN MANIFEST：

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

在onclick（）函数的java代码中，名称为onSubmit（）：

public class MainActivity extends AppCompatActivity {
  private int PHONE_STATE_CODE=1;

  private Button button;
  TextView textView;

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

    textView = (TextView) findViewById( R.id.textView2 );
  }

  public void onSubmit(View v){
    TelephonyManager t = (TelephonyManager) getSystemService( 
    Context.TELEPHONY_SERVICE );
    if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.READ_PHONE_STATE) == PackageManager.PERMISSION_GRANTED) {
      Toast.makeText(MainActivity.this, "you have already granted", Toast.LENGTH_SHORT).show();
    } else {
      reqPhonePermission();
    }

    String me =t.getDeviceId();

    String id = t.getLine1Number();
  }

~~~~~~~ 在onClick（）

之外

private void reqPhonePermission(){
    if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.READ_PHONE_STATE)){
        new AlertDialog.Builder(this).setTitle("permission needed").setMessage("this permission needed")
                .setPositiveButton("ok", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
                        ActivityCompat.requestPermissions(MainActivity.this,new String[]{Manifest.permission.READ_PHONE_STATE},PHONE_STATE_CODE);

                    }
                }) .setNegativeButton("cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {
                dialogInterface.dismiss();
            }
        }).create().show();
    } else {
        ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.READ_PHONE_STATE},PHONE_STATE_CODE);
    }
}

public void onRequestPermissionResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults ){
    if(requestCode == PHONE_STATE_CODE){
        if(grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
            Toast.makeText(this,"Permission granted",Toast.LENGTH_SHORT).show();
        } else {
            Toast.makeText(this,"Permission denied",Toast.LENGTH_SHORT).show();
        }
    }

Answer 1

只有在授予权限的情况下才应调用需要权限的方法当其中一个条件成立时，您可以确定授予权限：

ContextCompat.checkSelfPermission == PackageManager.PERMISSION_GRANTED
grantResults[0] == PackageManager.PERMISSION_GRANTED

尝试使用此代码：

public void onSubmit(View v){
    TelephonyManager t = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE );
    if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.READ_PHONE_STATE) == PackageManager.PERMISSION_GRANTED) {
        Toast.makeText(MainActivity.this, "you have already granted", Toast.LENGTH_SHORT).show();
        methodThatRequiresPermission();
    } else {
        reqPhonePermission();
    }
}

public void onRequestPermissionResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults ){
    if(requestCode == PHONE_STATE_CODE){
        if(grantResults.length > 0 && grantResults[0] ==  PackageManager.PERMISSION_GRANTED){
            Toast.makeText(this,"Permission granted",Toast.LENGTH_SHORT).show();
            methodThatRequiresPermission();
        } else {
            Toast.makeText(this,"Permission denied",Toast.LENGTH_SHORT).show();
        }
    }
}

private void methodThatRequiresPermission() { 
    String me =t.getDeviceId();
    String id = t.getLine1Number();

    //Use the values here
}

Android studio请求权限和IMEI / MEID

1 个答案: