findViewById in onCreate returns NULL when using Fragment

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Call findViewById from onCreateView


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>

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Important: Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB

int layout = Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB ?

				android.R.layout.simple_list_item_activated_1 :

android.R.layout.simple_list_item_1;





 getListView().setChoiceMode(ListView.CHOICE_MODE_SINGLE);

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Example of usage:



public void updateList() {
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		String[] from = { Notes.COLUMN_TITLE };
		int[] to = { android.R.id.text1 };
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/..................
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115

Progressbar change background and fore color - Android sample | progressbar-background-and-fore-color-android-sample

MainActivity.java


        ProgressBar mProgressBarScore;
      // onCreate
	mProgressBarScore = (ProgressBar)findViewById(R.id.progressBarScore);
	Resources res = getResources();
	mProgressBarScore.setProgressDrawable(res.getDrawable( R.drawable.my_progress));

res/layout/main.xml


       <ProgressBar
            android:id="@+id/progressBarScore"
            style="?android:attr/progressBarStyleHorizontal"
            android:layout_width="fill_parent"
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res/drawable/my_progress.xml










    

        

        

                        android:startColor="#FF001A"

                android:centerColor="#ff5a5d5a"

                android:centerY="0.75"

                android:endColor="#FF001A"

                android:angle="270"

        />

    







    

        

            

                                android:startColor="#80ffd300"

                    android:centerColor="#80ffb600"

                    android:centerY="0.75"

                    android:endColor="#a0ffcb00"

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            />

        

    



    android:id="@android:id/progress"

>

    

        

            

                            android:radius="10dip" />

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256

Save Restore Array List Android Example | save-restore-array-list-android-example


        int[] mArrayOfInt;
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128

How get Drawable Android example | how-get-drawable-android-example

InputStream, getResources(),openRawResource()


 java.io.InputStream is;
is = context.getResources().openRawResource(R.drawable.my_image);

Drawable mDrawable = context.getResources().getDrawable(R.drawable.button);
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Drawable[] mDrawables;
int[] resIDs = new int[] {
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                R.drawable.btn_help
            };
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135

Draw Arc Android basic example | draw-arc-android-basic-example

drawArc(), Canvas, Paint, setStyle()


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.CYAN);
			Paint p = new Paint();
			// smooths
			p.setAntiAlias(true);
			p.setColor(Color.RED);
			p.setStyle(Paint.Style.STROKE); 
			p.setStrokeWidth(5);
			// opacity
			//p.setAlpha(0x80); //
 
			RectF rectF = new RectF(50, 20, 100, 80);
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Editace: 2014-07-12 13:48:55
Počet článků v kategorii: 397
Url:findviewbyid-in-oncreate-returns-null-when-using-fragment

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