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Delete Bitmap Android Example

If some memory leak - problem try release of memory used of a big Bitmap what already not to need;
Bitmpap bmp; // not null
bmp.recycle();
bmp = null;

final boolean bmpIsRecycled = bmp.isRecycled()
// Returns true if this bitmap has been recycled.


//developer.android.com/reference/android/graphics/Bitmap.html
Free the native object associated with this bitmap, and clear the reference to the pixel data. This will not free the pixel data synchronously; it simply allows it to be garbage collected if there are no other references. The bitmap is marked as "dead”, meaning it will throw an exception if getPixels() or setPixels() is called, and will draw nothing. This operation cannot be reversed, so it should only be called if you are sure there are no further uses for the bitmap. This is an advanced call, and normally need not be called, since the normal GC process will free up this memory when there are no more references to this bitmap.

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344

Pixel to density independent pixel to pixel conversion | pixel-to-density-independent-pixel-to-pixel-conversion


Physical pixel (px)
Density independent pixel (dp)
Dots per inch (dpi) .. physical pixels per inch
px = dp * (dpi / 160)

public static int dpToPx(int dp)
{
    return (int) (dp * Resources.getSystem().getDisplayMetrics().density);
}

public static int pxToDp(int px)
{
    return (int) (px / Resources.getSystem().getDisplayMetrics().density);
}
142

Create bitmap and draw text into bitmap Android example | create-bitmap-and-draw-text-into-bitmap-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.GREEN);
            
           Bitmap b = Bitmap.createBitmap(200, 200, Bitmap.Config.ALPHA_8);
           Canvas c = new Canvas(b);
           c.drawRect(0, 0, 200, 200, paint);
           
           paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC));
           paint.setTextSize(40);
           paint.setTextScaleX(1.f);
           paint.setAlpha(0);
           paint.setAntiAlias(true);
           c.drawText("Your text", 30, 40, paint);
           paint.setColor(Color.RED);
           
           canvas.drawBitmap(b, 10,10, paint);
		}

	}
}


android/draw-text-into-bitmap-android.png

54

Timer simple TimerTask Java Android example | timer-simple-timertask-java-android-example


TimerTask with updating of TextView here




package cz.okhelp.timer;

import java.util.Timer;
import java.util.TimerTask;

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;

public class TimerActivity extends Activity {
TextView hTextView;
@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        hTextView = (TextView)findViewById(R.id.idTextView);
        MyTimerTask myTask = new MyTimerTask();
        Timer myTimer = new Timer();
//        public void schedule (TimerTask task, long delay, long period) 
//        Schedule a task for repeated fixed-delay execution after a specific delay.
//
//        Parameters
//        task  the task to schedule. 
//        delay  amount of time in milliseconds before first execution. 
//        period  amount of time in milliseconds between subsequent executions. 

        myTimer.schedule(myTask, 3000, 1500);        
        
    }
class MyTimerTask extends TimerTask {
	  public void run() {
		  // ERROR
		 hTextView.setText("Impossible");
		 // how update TextView in link below  
                 // //android.okhelp.cz/timer-task-timertask-run-cancel-android-example/
                 
	    System.out.println("");
	  }
	}


}


//android.okhelp.cz/asynctask-example-android-with-progressbar/
//android.okhelp.cz/timer-task-timertask-run-cancel-android-example/
21

How to install mount SD card for Eclipse Android Emulator | how-install-sd-card-on-android-eclipse-emulator


If you want download some *.apk file from internet and try on your emulator you get error than you have to install SD card. You have to closing Android emulator.
Mount Android emulator SD card instruction

  1. In Eclipse go in menu Window - Android SDK and Avg Manager

  2. Select Virtual devices

  3. Select AVD Name where you need install SD card

  4. Click on Edit button

  5. In open dialog go to SD card - Size: and write 500

  6. Press button Edit AVD

  7. Run AVD emulator


Image how install SD card on Android emulator in Eclipse.