Android 6.0 系統默認爲targetSdk Version 小於 23 的應用授予了所申請的所有權限,如果你的 app 設置的 targetSdk Version 小於 23,在運行時不會因爲權限的問題而崩潰,當 targetSdk Version 大於 23 時,app 不得不在運行時來詢問用戶授予權限,當然了,也不是所有權限都需要詢問,Google 把權限分爲兩類,一類是普通權限(Normal Permission),這類權限一般不會涉及到用戶的隱私,另一類是危險權限(Dangerous Permission),這類權限會涉及到用戶隱私,需要用戶授權。
動態申請權限:
這裏我用 permission.CALL_PHONE 這個權限來做演示:
(1) 在 AndroidManifest.xml 裏面註冊撥打電話的權限:
<uses-permission android:name="android.permission.CALL_PHONE"/>
(2) Java 代碼如下:
import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
private Button button;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = findViewById(R.id.btn_call);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
call();
}
});
}
private void call() {
//檢查是否有撥打電話的權限
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CALL_PHONE)
!= PackageManager.PERMISSION_GRANTED) {
//申請權限
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.CALL_PHONE},
1);
} else {
callPhone();
}
}
private void callPhone() {
Intent intent = new Intent(Intent.ACTION_CALL);
Uri uri = Uri.parse("tel:" + "10086");
intent.setData(uri);
try{
startActivity(intent);
} catch (SecurityException e) {
e.printStackTrace();
}
}
//申請權限回調
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
@NonNull int[] grantResults) {
if (requestCode == 1) {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
callPhone();
} else {
Toast.makeText(this, "權限被拒絕", Toast.LENGTH_LONG).show();
}
}
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
}
}