利用Android的Canvas绘制正弦函数图像

一时兴起用android原生的基础绘制工具，绘制了一个正弦（余弦）函数图象，不多说，先上图：

MainView.java类

package com.zhaofeng.main;import javax.crypto.SealedObject;import android.app.Activity;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.Path;import android.graphics.Point;import android.os.Bundle;import android.os.Handler;import android.view.SurfaceHolder;import android.view.SurfaceHolder.Callback;import android.view.SurfaceView;public class MainView extends Activity {    /** Called when the activity is first created. */private SurfaceView surfaceView;private Paint paint;private SurfaceHolder surfaceHolder;private int scale_x = 20;private int scale_y = 50;private double ox=10;private double oy=240;private double x=0;private double y=0;private double t=0;private boolean flag=true;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                surfaceView = (SurfaceView) findViewById(R.id.main_suf);        surfaceHolder = surfaceView.getHolder();                paint = new Paint();              surfaceHolder.addCallback(new Callback() {@Overridepublic void surfaceDestroyed(SurfaceHolder holder) {// TODO Auto-generated method stub}@Overridepublic void surfaceCreated(SurfaceHolder holder) {// TODO Auto-generated method stubnew Thread(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubwhile (flag) {try {Thread.sleep(10);Canvas canvas=surfaceHolder.lockCanvas();if(canvas!=null){//绘制坐标轴paint.setColor(Color.WHITE);canvas.drawText("O",20,220, paint);paint.setColor(Color.BLUE);canvas.drawLine(10,10,10,480, paint);canvas.drawText("Y",20,30, paint);paint.setColor(Color.GREEN);canvas.drawLine(0,240,320,240, paint);canvas.drawText("X",300,260, paint);//绘制正弦曲线t+=0.1;x=t*scale_x;y=Math.sin(t)*scale_y+240;System.out.println("---------"+Math.round(Math.sin(t)));if (t>0) {paint.setColor(Color.RED);canvas.drawLine(10+(int)ox,(int)oy,10+(int)x,(int)y, paint);System.out.println(x+"s"+y);}ox=x;oy=y;if (t>15) {flag=false;}}surfaceHolder.unlockCanvasAndPost(canvas);} catch (InterruptedException e) {e.printStackTrace();}}}}).start();}@Overridepublic void surfaceChanged(SurfaceHolder holder, int format, int width,int height) {// TODO Auto-generated method stub}});    }}

main.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    ><SurfaceView  android:id="@+id/main_suf"    android:layout_width="fill_parent"     android:layout_height="fill_parent"     android:text="@string/hello"    /></LinearLayout>