package com.loaderman.lovecircledemo;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LoveView view = new LoveView(this); setContentView(view); }}
package com.loaderman.lovecircledemo;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.RectF;import android.graphics.Typeface;import android.view.SurfaceHolder;import android.view.SurfaceView;public class LoveView extends SurfaceView implements SurfaceHolder.Callback, Runnable { boolean mbloop = false; SurfaceHolder mSurfaceHolder = null; private Canvas canvas; int miCount = 0; int y = 50; /** * @param context */ public LoveView(Context context) { super(context); mSurfaceHolder = this.getHolder(); mSurfaceHolder.addCallback(this); this.setFocusable(true); this.setKeepScreenOn(true); mbloop = true; } @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { } @Override public void surfaceCreated(SurfaceHolder holder) { new Thread(this).start(); } @Override public void surfaceDestroyed(SurfaceHolder holder) { mbloop = false; } @Override public void run() { // TODO Auto-generated method stub while (mbloop) { try { Thread.sleep(500); } catch (Exception e) { // TODO: handle exception } synchronized (mSurfaceHolder) { Draw(); } } } private void Draw() { // TODO Auto-generated method stub canvas = mSurfaceHolder.lockCanvas(); try { if (mSurfaceHolder == null || canvas == null) { return; } if (miCount < 100) { miCount++; } else { miCount = 0; } Paint paint = new Paint(); paint.setAntiAlias(true); paint.setColor(Color.BLACK); canvas.drawRect(0, 0, 320, 480, paint); switch (miCount % 6) { case 0: paint.setColor(Color.BLUE); break; case 1: paint.setColor(Color.GREEN); break; case 2: paint.setColor(Color.RED); break; case 3: paint.setColor(Color.YELLOW); break; case 4: paint.setColor(Color.argb(255, 255, 181, 216)); break; case 5: paint.setColor(Color.argb(255, 0, 255, 255)); break; default: paint.setColor(Color.WHITE); break; } int i, j; double x, y, r; for (i = 0; i <= 90; i++) { for (j = 0; j <= 90; j++) { r = Math.PI / 45 * i * (1 - Math.sin(Math.PI / 45 * j)) * 20; x = r * Math.cos(Math.PI / 45 * j) * Math.sin(Math.PI / 45 * i) + 320 / 2; y = -r * Math.sin(Math.PI / 45 * j) + 400 / 4; canvas.drawPoint((float) x, (float) y, paint); } } paint.setTextSize(32); paint.setTypeface(Typeface.create(Typeface.SERIF, Typeface.ITALIC)); RectF rect = new RectF(60, 400, 260, 405); canvas.drawRoundRect(rect, (float) 1.0, (float) 1.0, paint); canvas.drawText("Loving You", 75, 400, paint); mSurfaceHolder.unlockCanvasAndPost(canvas); } catch (Exception e) { e.printStackTrace(); } }} 效果图:
- 画图的时候你可以继承View,也可以继承SurfaceView,这两者的区别在于：surfaceView是在一个新起的单独线程中可以重新绘制画面而View必须在UI的主线程中更新画面。SurfaceView可以控制表面的格式，比如大小，显示在屏幕中的位置，最关键是的提供了SurfaceHolder类，使用getHolder方法获取，还有涉及的surfaceCreated（SurfaceHolder holder）,surfaceDestroyed(SurfaceHolder holder),surfaceChanged(SurfaceHolder holder, int format, int width, int height)方法，而在SurfaceHolder.Callback 接口回调中可以通过重写来改变这些方法
- 程序其实很简单， 既然生命了Runnable接口，就有相对应的Run方法，在surfaceCreate（）的时候开启线程，线程每隔500ms就刷新一次，这样我们看到的效果就是闪烁的，每500毫秒 画一次图，根据经过的间隔时间来设置画笔的颜色，然后通过循环描点，画出心形，然后设置字体大小，画字和字下面的横线。
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