我正在为Android棉花糖(API LEvel 23)开发一个应用程序。
我有一个包含ListView的"活动"
我使用BaseView适配器填充该ListView。
每当我按下ListView中的按钮时,我都想启动"活动"
然而,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"活动"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Adapter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获得了一个额外的db参数
这是一个SQLite数据库对象,它在适配器中使用,但这并不相关。
我不知道如何使用onClick
覆盖来调用我的扫描活动
我尝试将父Activity作为参数传递到Adapter中,并调用扫描方法,但我得到了以下异常:
java.lang.IllegalArgumentException: Can only use lower 8 bits for requestCode`
有人能解决我的问题吗?
由于使用-1(PackageManager.PERMISSION_DENIED)
作为requestPermissions
方法的requestCode
,因此会出现java.lang.IllegalArgumentException: Can only use lower 8 bits for requestCode
错误。
要使其工作,请使用1到255之间的任何requestCode
。
public final int got_camera = 24;