Question

我正在为Android Marshmallow开发一个应用程序（API LEvel 23）。

我有一个包含ListView的Activity 我使用BaseView适配器填充ListView。

每当我在ListView中按下按钮时，我想启动一个Activity 但是，此活动需要访问相机，在最新的Android版本中，这意味着我应该在运行时请求相机权限使用Activity的相机将是ZXing活动。

这是活动代码：

public class ProviderListActivity extends AppCompatActivity {

    public boolean can_access_camera = false;
    public final int got_camera = PackageManager.PERMISSION_DENIED;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_provider_list);
        ListView listView = (ListView) findViewById(R.id.ProviderListView);
        CardsDBHelper dbHelper = new CardsDBHelper(this);
        SQLiteDatabase db = dbHelper.getWritableDatabase();
        listView.setAdapter(new ProviderListAdapter(this, db));
    }

    public void start_scan(){
        if (have_camera_permission()){
            start_scan_activity();
        } else {
            Log.d("ProviderListActivity", "I CANNOT ACCESS THE CAMERA");
        }
    }

    public void start_scan_activity(){
        IntentIntegrator integrator = new IntentIntegrator(this);
        integrator.initiateScan();
    }

    public boolean have_camera_permission(){
        //Check for permissions
        int permissionCheck = ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA);
        if (permissionCheck == PackageManager.PERMISSION_DENIED){
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CAMERA}, got_camera);
        } else {
            can_access_camera = true;
        }
        return can_access_camera;
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        switch (requestCode) {
            case got_camera: {
                // If request is cancelled, the result arrays are empty.
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    can_access_camera = true;
                } else {
                    can_access_camera = false;
                }
                return;
            }
            // other 'case' lines to check for other
            // permissions this app might request
        }
    }
}

我的适配器中的getView()方法是：

public View getView(int position, View convertView, final ViewGroup parent) {
Button grid_button;
    if (convertView == null) {
        // if it's not recycled, initialize some attributes
        grid_button = new Button(mContext);
        grid_button.setText("Hello Text");
        Drawable d = mContext.getDrawable(R.drawable.circle);
    grid_button.setCompoundDrawablesRelativeWithIntrinsicBounds(null,d,null,null);
    grid_button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            //What do I need to put inside here?
        }
    });
} else {
    grid_button = (Button) convertView;
}

return grid_button;
}

您可能已经注意到Adapter获得了额外的db参数这是一个SQLite数据库对象，它在Adapter中使用，但这不相关。

我不确定如何使用onClick覆盖来调用我的扫描活动我尝试将父Activity作为参数传递给适配器并调用scan方法，但我得到以下异常：

java.lang.IllegalArgumentException: Can only use lower 8 bits for requestCode`

有没有人能解决我的问题？

Answer 1

您收到java.lang.IllegalArgumentException: Can only use lower 8 bits for requestCode错误，因为-1(PackageManager.PERMISSION_DENIED)方法使用requestCode requestPermissions。

要使其有效，请使用 1 与 255 之间的任何requestCode。

public final int got_camera = 24;

Android 6 Marshmallow ListView。使用运行时权限启动活动

1 个答案: