Code with error:

ImageView imgV = (ImageView)findViewById(R.id.myView);
        imgV.setLayoutParams(new ViewGroup.LayoutParams(
        		ViewGroup.LayoutParams.WRAP_CONTENT,
        		0));

If you get error try this code:

        ViewGroup.LayoutParams layoutParams = imgV
				.getLayoutParams();
		layoutParams.height = 0;
		imgV.setLayoutParams(layoutParams);

java.lang.ClassCastException: android.view.ViewGroup$LayoutParams
at android.widget.LinearLayout.measureHorizontal(LinearLayout.java:659)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:311)
at android.view.View.measure(View.java:8313)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1017)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:386)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:309)
at android.view.View.measure(View.java:8313)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
at android.view.View.measure(View.java:8313)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:531)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:309)
at android.view.View.measure(View.java:8313)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
at android.view.View.measure(View.java:8313)

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);
             paint.setColor(Color.BLUE);
            
            Shader mShader = new LinearGradient(0, 0, 100, 70, new int[] {
                    Color.RED, Color.GREEN, Color.BLUE },
                    null, Shader.TileMode.MIRROR);  // CLAMP MIRROR REPEAT
            Canvas c = new Canvas(b);
            paint.setShader(mShader);
            //c.drawCircle(60, 60, 30, paint);
            c.drawRect(0, 0, 200, 200, paint);
            canvas.drawBitmap(b, 10,10, paint);
		}

	}
}

do while Java example

public class MainClass {
	public static void main(String[] arg) {
			String[] arrayOfString = { "Hello", "people", "hello", "world!" };
			int i = 0;
                        // first cycle is always executed
			do {
				System.out.println("Loop: " + i);
				System.out.println(arrayOfString[i]);
				i++;
				
			}while ( i == -1 );
	}
}
/*
Loop: 0
Hello
*/

public class MainClass {
	public static void main(String[] arg) {
			String[] arrayOfString = { "Hello", "people", "hello", "world!" };
			int i = 0;
			do {
				System.out.println("Loop: " + i);
				System.out.println(arrayOfString[i]);
				i++;
				
			}while ( i < arrayOfString.length );
	}
}
/*
Loop: 0
Hello
Loop: 1
people
Loop: 2
hello
Loop: 3
world!
*/

How add item to ArrayList, sort ArrayList, search find index of item in ArrayList, min(), max() Java basic example.

import java.util.ArrayList;
import java.util.Collections;

public class MainClass {
	public static void main(String[] arg) {
		String[] arrayOfString = {"nothing", "Hello", "people"
				, "bye-bye", "hello", "world!", "End" };
		   ArrayList<String> arrayList = new ArrayList<String>();
            for(String s: arrayOfString)
		     arrayList.add(s);

		    Collections.sort(arrayList);
		    // foreach
		    for (String str: arrayList)
		      System.out.println(str);
		    
		    Object objMin = Collections.min(arrayList);
		    System.out.println("Min is: " + objMin);
		    
		    Object objMax = Collections.max(arrayList);
		    System.out.println("Max is: " + objMax);
		    
		    int index = Collections.binarySearch(arrayList, "people");
		    System.out.println("Index of people is: " + index);
		    
		  }

		
	
}
/*
End
Hello
bye-bye
hello
nothing
people
world!
Min is: End
Max is: world!
Index of people is: 5
*/

Map TreeMap add key value pair get find pair by key Java Android example.

MainClass.java

import java.util.Map;
import java.util.TreeMap;

public class MainClass {
	public static void main(String[] arg) {
		
		// english;germany dictionary
		String[] arrayOfString = { "one;eine", "two;zwei", "three;drei" };

		Map<String, String> map = new TreeMap<String, String>();
	    
		for(String s: arrayOfString){
	    	String[] array = s.split(";");
	    	String sKey ="", sValue="";
	    	if(array.length > 1){
	    	sKey = array[0]; sValue = array[1];
	    		map.put(sKey, sValue);
	    	}
	    }

       // check if key exists 	    
	   if( map.containsKey("two")){
		System.out.print("two = " + map.get("two"));
	   }
	}
}
/*
two = zwei
 */