Every fragment must have an empty constructor Android Java Class
You have to add constructor!
public static class YourFragment extends Fragment {
//you have to add constructor!!!!!
public YourFragment(){}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.activity_main, container, false);
return view;
}
}
396LW NO topic_id
AD
Další témata ....(Topics)
Canvas, drawLine(), setStrokeWidth(), Paint, setAntiAlias(boolean), onDraw()
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new SampleView(this));
}
private static class SampleView extends View {
// CONSTRUCTOR
public SampleView(Context context) {
super(context);
setFocusable(true);
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.YELLOW);
Paint p = new Paint();
// smooths
p.setAntiAlias(true);
p.setColor(Color.RED);
p.setStrokeWidth(4.5f);
// opacity
p.setAlpha(0x80); //
// drawLine (float startX, float startY, float stopX, float stopY,
// Paint paint)
canvas.drawLine(0, 0, 40, 40, p);
canvas.drawLine(40, 0, 0, 40, p);
}
}
}
Copy file to another
Copy and compress file
File path = Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES);
File file = new File(path, "MyPicture.jpg");
// the Pictures directory exists?
path.mkdirs();
InputStream is = getResources().openRawResource(R.drawable.flower_blue);
OutputStream os = new FileOutputStream(file);
byte[] data = new byte[is.available()];
is.read(data);
os.write(data);
is.close();
os.close();
Copy and compress file
Bitmap bitmapOrg = BitmapFactory.decodeResource(getResources(),
R.drawable.flower_blue);
try {
FileOutputStream out = new FileOutputStream("new_bitmap.jpg");
bitmapOrg.compress(Bitmap.CompressFormat.JPEG, 90, out);
} catch (Exception e) {
e.printStackTrace();
Log.e("saveBitmap", e.getMessage());
}
Add and shuffle elements in LinkedList or ArrayList Java basic example.
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
public class MainClass {
public static void main(String[] arg) {
String[] arrayOfString = {"nothing", "Hello", "people"
, "bye-bye", "hello", "world!", "End" };
List<String> arrayList = new LinkedList<String>();
for(String s: arrayOfString)
arrayList.add(s);
Collections.shuffle(arrayList);
System.out.println(arrayList);
}
}
/*
[hello, world!, bye-bye, nothing, people, End, Hello]
*/
You have to put your font fonts/samplefont.ttf into assets/fonts folder in your project!
// set own custom font from assets
TextView txt = (TextView) findViewById(R.id.custom_font);
Typeface mFace = Typeface.createFromAsset(getContext().getAssets(),
"fonts/samplefont.ttf");
txt.setTypeface(mFace);
If You create new xml file with prefix _ , for example _style.xml and You to clean project (Project->Clean), than package in folder project\gen will deleted with R.java class and new R.java not be created.
For to solving this problem You have to rename file without prefix _ as style.xml or name what You need and rebuild project.
If some ID cannot be resolved or is not a field get error occurence
You have to delete import android.R; in Activity.class if was inserted,
when this error is displayed.
For to solving this problem You have to rename file without prefix _ as style.xml or name what You need and rebuild project.
If some ID cannot be resolved or is not a field get error occurence
You have to delete import android.R; in Activity.class if was inserted,
when this error is displayed.
Editace: 2014-09-10 10:40:35
Počet článků v kategorii: 396
Url:every-fragment-must-have-an-empty-constructor-android-java-class