findViewById in onCreate returns NULL when using Fragment
Call findViewById from onCreateView
res\layout
activity_main.xml
fragment_main.xml
public class MainActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.containerMoje, new PlaceholderFragment()).commit();
}
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);
if (container == null) {
return null;
}
TextView mText;
mText = (TextView)rootView.findViewById(R.id.idText);
mText.setText("Hello from fragment_main");
return rootView;
}
}
}
res\layout
activity_main.xml
<FrameLayout xmlns:android="//schemas.android.com/apk/res/android"
xmlns:tools="//schemas.android.com/tools"
android:id="@+id/containerMoje"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="cz.okhelp.autoskola.MainActivity"
tools:ignore="MergeRootFrame" />
fragment_main.xml
<RelativeLayout xmlns:android="//schemas.android.com/apk/res/android"
xmlns:tools="//schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="cz.okhelp.autoskola.MainActivity$PlaceholderFragment" >
<TextView
android:id="@+id/idText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/hello_world" />
</RelativeLayout>
396LW NO topic_id
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Další témata ....(Topics)
int nf = Math.round(5.789f);
System.out.print(nf); // 6
float f = 28.611f;
int n3 = Math.round(f);
System.out.println(n3); // 29
double d = 1234.56;
long lon = Math.round(d);
System.out.println(lon); // 1235
int diff = 90 - 40;
// float fDeleni = diff / 10; // error code
float fDeleni = (float)diff / 10.f; // ok
int nRound = Math.round(fDeleni);
// Caution:
int n2 = (int) 8.999f;
System.out.println(n2); // 8
Black and white bitmap image pictures, gray scale colormatrix Android example.
public class ApokusActivity 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) {
Paint paint = new Paint();
canvas.drawColor(Color.YELLOW);
// you need to insert a image flower_blue into res/drawable folder
paint.setFilterBitmap(true);
Bitmap bitmapOrg = BitmapFactory.decodeResource(getResources(),
R.drawable.flower_blue);
canvas.drawBitmap(bitmapOrg, 10, 10, paint);
int width, height;
ColorMatrix cm = new ColorMatrix(
new float[]{
0.5f,0.5f,0.5f,0,0,
0.5f,0.5f,0.5f,0,0,
0.5f,0.5f,0.5f,0,0,
0,0,0,1,0,0,
0,0,0,0,1,0
});
cm.setSaturation(0);
ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);
paint.setColorFilter(f);
int h = bitmapOrg.getHeight();
//canvas.drawBitmap(bitmapOrg, 10, 10, paint);
canvas.drawBitmap(bitmapOrg, 10, 10 + h + 10, paint);
}
}
}
Pictures taken by front camera Lenovo A6000 smartpohone - review.
Do not take pictures against the sun.
Stay in the shade. Keep lens clean.
Night without flash
Misty - smog
Without flash in room - TV screen
Do not take pictures against the sun.
Stay in the shade. Keep lens clean.
Night without flash
Misty - smog
Without flash in room - TV screen
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) {
Paint paint = new Paint();
canvas.drawColor(Color.GREEN);
Bitmap b = Bitmap.createBitmap(200, 200, Bitmap.Config.ALPHA_8);
paint.setColor(Color.BLUE);
Canvas c = new Canvas(b);
c.drawRect(0, 0, 200, 200, paint);
canvas.drawBitmap(b, 10,10, paint);
}
}
}
break statement in Java Android basic example
MainClass.java
MainClass.java
public class MainClass {
public static void main(String[] arg) {
String[] arrayOfString = {"nothing", "Hello", "people"
, "bye-bye", "hello", "world!", "end" };
for (int i = 0; i < arrayOfString.length; i++) {
System.out.println(arrayOfString[i]);
if(i > 2)
break; // end of loop
}
}
}
/*
nothing
Hello
people
bye-bye
*/
Editace: 2014-07-12 13:48:55
Počet článků v kategorii: 396
Url:findviewbyid-in-oncreate-returns-null-when-using-fragment
