04_响应单点触控

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.TextView;

public class MainActivity extends Activity implements OnTouchListener {

  StringBuilder builder = new StringBuilder();
     TextView textView;

     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         textView = new TextView(this);
         textView.setText("Touch and drag (one finger only)!");
         textView.setOnTouchListener(this);
         setContentView(textView);
     }

     @Override
     public boolean onTouch(View v, MotionEvent event) {
         builder.setLength(0);
         switch (event.getAction()) {
         case MotionEvent.ACTION_DOWN:
             builder.append("down, ");
             break;
         case MotionEvent.ACTION_MOVE:
             builder.append("move, ");
             break;
         case MotionEvent.ACTION_CANCEL:
             builder.append("cancle, ");
             break;
         case MotionEvent.ACTION_UP:
             builder.append("up, ");
             break;
         }
         builder.append(event.getX());
         builder.append(", ");
         builder.append(event.getY());
         String text = builder.toString();
         Log.d("TouchTest", text);
         textView.setText(text);
         return true;
     }

}