title: canvas drawing is not working in android
body: <p>i have made a simple android painting program for learning purpose,But ontouch stroke is not drawing ,i have tried as below:
  <strong>main.java</strong></p>
  
  <pre><code>package com.example.mypen;
  
  import android.os.Bundle;
  import android.app.Activity;
  import android.graphics.Canvas;
  import android.graphics.Color;
  import android.graphics.Paint;
  import android.graphics.Path;
  import android.view.Menu;
  import android.view.*;
  import android.view.MotionEvent;
  
  public class MainActivity extends Activity{
      private Paint paint = new Paint();
        private Path path = new Path();
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
          paint.setAntiAlias(true);
          paint.setStrokeWidth(6f);
          paint.setColor(Color.BLACK);
          paint.setStyle(Paint.Style.STROKE);
          paint.setStrokeJoin(Paint.Join.ROUND);
      }
  
      public void onDraw(Canvas canvas){
          canvas.drawPath(path,paint);
          }
      public boolean onTouchEvent(MotionEvent me){
          float eventX=me.getX();
          float eventY=me.getY();
  
          switch (me.getAction()) {
          case MotionEvent.ACTION_DOWN:
              path.moveTo(eventX, eventY);
              return true;
          case MotionEvent.ACTION_MOVE:
              path.lineTo(eventX, eventY);
              break;
          case MotionEvent.ACTION_UP:
              break;
          }
          return true;
  
      }
  
  }
  </code></pre>