Drawing on SurfaceView
Last post introduce "A basic implementation of SurfaceView". To draw something on the SurfaceView, place the codes in-between surfaceHolder.lockCanvas() and surfaceHolder.unlockCanvasAndPost(canvas).
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| package com.TestSurefaceView;import java.util.Random;import android.app.Activity;import android.content.Context;import android.graphics.Canvas;import android.graphics.Paint;import android.os.Bundle;import android.view.SurfaceHolder;import android.view.SurfaceView;public class TestSurefaceView extends Activity { MySurfaceView mySurfaceView; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mySurfaceView = new MySurfaceView(this); setContentView(mySurfaceView); } @Override protected void onResume() { // TODO Auto-generated method stub super.onResume(); mySurfaceView.onResumeMySurfaceView(); } @Override protected void onPause() { // TODO Auto-generated method stub super.onPause(); mySurfaceView.onPauseMySurfaceView(); } class MySurfaceView extends SurfaceView implements Runnable{ Thread thread = null; SurfaceHolder surfaceHolder; volatile boolean running = false; private Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG); Random random; public MySurfaceView(Context context) { super(context); // TODO Auto-generated constructor stub surfaceHolder = getHolder(); random = new Random(); } public void onResumeMySurfaceView(){ running = true; thread = new Thread(this); thread.start(); } public void onPauseMySurfaceView(){ boolean retry = true; running = false; while(retry){ try { thread.join(); retry = false; } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } @Override public void run() { // TODO Auto-generated method stub while(running){ if(surfaceHolder.getSurface().isValid()){ Canvas canvas = surfaceHolder.lockCanvas(); //... actual drawing on canvas paint.setStyle(Paint.Style.STROKE); paint.setStrokeWidth(3); int w = canvas.getWidth(); int h = canvas.getHeight(); int x = random.nextInt(w-1); int y = random.nextInt(h-1); int r = random.nextInt(255); int g = random.nextInt(255); int b = random.nextInt(255); paint.setColor(0xff000000 + (r << 16) + (g << 8) + b); canvas.drawPoint(x, y, paint); surfaceHolder.unlockCanvasAndPost(canvas); } } } }}
akm
www.cdacians.com
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