Android的Canvas绘制正弦函数图像

来源：互联网发布：js验证非负整数编辑：程序博客网时间：2024/04/29 16:29
package com.baozilichao.test009;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.SurfaceHolder;import android.view.SurfaceView;public class MainActivity extends AppCompatActivity {    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.activity_main);        surfaceView = (SurfaceView) findViewById(R.id.main_suf);        surfaceHolder = surfaceView.getHolder();        paint = new Paint();        surfaceHolder.addCallback(new SurfaceHolder.Callback() {            @Override            public void surfaceDestroyed(SurfaceHolder holder) {                // TODO Auto-generated method stub            }            @Override            public void surfaceCreated(SurfaceHolder holder) {                // TODO Auto-generated method stub                new Thread(new Runnable() {                    @Override                    public void run() {                        // TODO Auto-generated method stub                        while (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();            }            @Override            public void surfaceChanged(SurfaceHolder holder, int format, int width,                                       int height) {                // TODO Auto-generated method stub            }        });    }} <?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    tools:context="com.baozilichao.test009.MainActivity">    <SurfaceView        android:id="@+id/main_suf"        android:layout_width="fill_parent"        android:layout_height="fill_parent"        /></LinearLayout>
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