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Start Activity from list - launches other activities from list



Activities launcher

public class MainActivity extends ListActivity {
    private class Sample {
        private CharSequence title;
        private Class<? extends Activity> activityClass;

        public Sample(int titleResId, Class<? extends Activity> activityClass) {
            this.activityClass = activityClass;
            this.title = getResources().getString(titleResId);
        }

        @Override
        public String toString() {
            return title.toString();
        }
    }

    private static Sample[] mSamples;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Instantiate the list of samples.
        mSamples = new Sample[]{
                new Sample(R.string.title_first_app, FirstActivity.class),
                new Sample(R.string.title_second_app, SecondActivity.class),
                new Sample(R.string.title_third_app, ThirdActivity.class),
        };

        setListAdapter(new ArrayAdapter<Sample>(this,
                android.R.layout.simple_list_item_1,
                android.R.id.text1,
                mSamples));
    }

    @Override
    protected void onListItemClick(ListView listView, View view, int position, long id) {
        // Launch the sample associated with this list position.
        startActivity(new Intent(MainActivity.this, mSamples[position].activityClass));
    }
}


397LW NO topic_id



Další témata ....(Topics)


98

Activity Lifecycle if button Home pressed Android example | activity-lifecycle-if-button-home-pressed-android-example


If on Android emulator home button pressed.

// button home presssed
19:37:06.727: INFO/ActivityManager(60): Starting: 
Intent { act=android.intent.action.MAIN cat=[android.intent.category.HOME] 
flg=0x10200000 cmp=com.android.launcher/com.android.launcher2.Launcher } from pid 60

19:37:06.807: INFO/onSaveInstanceState(339): onSaveInstanceState()
19:37:06.848: INFO/onPause(339): onPause()
19:37:07.968: INFO/onStop(339): onStop()


Diagram of Activity lifecycle if button HOME pressed

life_cycle_button_home_pressed
300

SurfaceView implements Runnable Android Code | surfaceview-implements-runnable-android-code



package cz.okhelp.surfview;

import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.View.OnTouchListener;

public class MainActivity extends Activity implements OnTouchListener {
	OurView v;
	Bitmap ball, blob;
	float x, y;
	Sprite sprite;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		// setContentView(R.layout.activity_our_view);
		v = new OurView(this);
		v.setOnTouchListener(this);
		ball = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
		x = y = 0;
		setContentView(v);
	}


	@Override
	protected void onPause() {
		// TODO Auto-generated method stub
		super.onPause();
		v.pause();
	}

	@Override
	protected void onResume() {
		// TODO Auto-generated method stub
		super.onResume();
		v.resume();
	}

	public class OurView extends SurfaceView implements Runnable {
		Thread t = null;
		SurfaceHolder holder;
		boolean isItOK = false;

		public OurView(Context context) {
			super(context);
			// TODO Auto-generated constructor stub
			holder = getHolder();
		}

		public void run() {
			// TODO Auto-generated method stub
			while (isItOK == true) {
				// perform canvas drawing
				if (!holder.getSurface().isValid()) {
					continue;
				}
				// sprite = new Sprite(OurView.this,blob);
				Canvas c = holder.lockCanvas();
				c.drawARGB(255, 100, 100, 10);
				c.drawBitmap(ball, x, y, null);
				// onDraw(c);
				holder.unlockCanvasAndPost(c);
			}
		}

		protected void onDraw(Canvas canvas) {
			// sprite.onDraw(canvas);
		}

		public void pause() {
			isItOK = false;
			while (true) {
				try {
					t.join();
				} catch (InterruptedException e) {
					// TODO: handle exception
					e.printStackTrace();
				}
				break;
			}// end while
		}

		public void resume() {
			isItOK = true;
			t = new Thread(this);
			t.start();
		}
	}

	@Override
	public boolean onTouch(View v, MotionEvent event) {
		// TODO Auto-generated method stub
		try {
			Thread.sleep(50);
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		switch (event.getAction()) {
		case MotionEvent.ACTION_DOWN:
			x = event.getX();
			y = event.getY();

			break;
		case MotionEvent.ACTION_UP:
			x = event.getX();
			y = event.getY();

			break;
		case MotionEvent.ACTION_MOVE:
			x = event.getX();
			y = event.getY();

			break;
		}// end switch

		return true;
	}

}

137

Draw drawARGB() Android basic example | draw-drawargb-android-basic-example



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) {
			//drawARGB (int a, int r, int g, int b)
//			a  alpha component (0..255) of the color to draw onto the canvas 
//			r  red component (0..255) 
//			g  green component (0..255)  
//			b  blue component (0..255)  

			canvas.drawARGB(255, 0, 255, 10); 
		}

	}
}


109

Conversion to Dalvik format failed with error 1 | conversion-to-dalvik-format-failed-with-error-1


UNEXPECTED TOP-LEVEL EXCEPTION:
java.lang.IllegalArgumentException: already added: Lcz/okhelp/MyMathClass;

First try this solution!!!!!
Select your project in project tree and go to the Eclipse menu Project » Clean » Clean projects selected below » select your project and click OK.

If you create *.apk package with proguard sometimes you must back up the project, delete project, and create new project if you are unable to create *.apk file.

Check your AndroidManifest.xml if all Activity is correctly inserted. If you add a library project to Main project you have to insert Activity from library to Main project AndroidManifest.xml


Problem with the library.
I deleted library project from project tree and again put the _library project into the main project. This problem was resolved.
1.)Go to Project » Properties » Java Build Path » Libraries and remove (your projects) click OK.
2.)Go to Project » Clean » Clean projects selected below » select your project and click OK.
3.)Add again your LIBRARY project to your MAIN project Project » Properties » Java Build Path » Libraries.
See image below.

Problem with a *.apk file
If you create signed *.apk, you have to delete previous *.apk from your PC folder.

jar-library-create-with-eclipse

165

How to clear or hide an ImageView in Android | how-to-clear-or-hide-an-imageview-in-android



// solution 1
ImageView imageView = (ImageView)findViewById(R.id.myimage);
imageView.setImageDrawable(null);
// or
imageView.setImageResource(0);

// solution 2  hide ImageView
imageView.setVisibility(View.INVISIBLE);

// solution 3 resize ImageView 0, 0
 hImageViewSemafor.setLayoutParams(new LinearLayout.LayoutParams(0,0));


Editace Jana Žákovská : 2016-02-25 19:32:45
Počet článků v kategorii: 397
Url:start-activity-from-list-launches-other-activities-from-list
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