SurfaceView实现模拟时钟

最新推荐文章于 2024-06-14 15:44:16 发布

原创最新推荐文章于 2024-06-14 15:44:16 发布 · 533 阅读

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本文介绍了一个基于Android的智能计时器应用实现，详细解释了如何利用Java和Android SDK构建一个能够实时显示时间（小时、分钟、秒）的计时器应用，并通过调整角度绘制小时、分钟和秒指针。

package com.example.compassdemo;


import java.util.Calendar;
import java.util.Timer;
import java.util.TimerTask;

import android.os.Bundle;
import android.app.Activity;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Rect;
import android.graphics.RectF;
import android.util.DisplayMetrics;
import android.view.Display;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;
import android.view.WindowManager;

public class MainActivity extends Activity {
	SurfaceView view;
	SurfaceHolder s_hold; 
	
	//圆盘半径
	int radius=200;
	//屏幕的宽高
	int screenWidth;
	int screenHeight;
	//圆盘原点
	int cx;
	int cy;
	//画笔
	Paint paint;
	//文字
	String TEXT="http://app.ewolian.com/pages/count.jsp";
	
	//计数
	int COUNT=60;
	
	//计时器  
    Timer timer=new Timer();  
    TimerTask task=null;  
    
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        WindowManager windowManager=getWindowManager();  
        Display display=windowManager.getDefaultDisplay();  
        DisplayMetrics metrics=new DisplayMetrics();  
        display.getMetrics(metrics);  
        //获取屏幕的宽高
        screenHeight=metrics.heightPixels;//获取屏幕的高度  
        screenWidth=metrics.widthPixels;
        //设置圆盘的圆心
        cx=screenWidth/2;
        cy=screenHeight/2-40;
        
        view=(SurfaceView) findViewById(R.id.sView);
        s_hold=view.getHolder();
        s_hold.addCallback(new Callback() {

			@Override
			public void surfaceChanged(SurfaceHolder holder, int arg1, int arg2,
					int arg3) {
				// TODO Auto-generated method stub
			}

			@Override
			public void surfaceCreated(SurfaceHolder holder) {
				// TODO Auto-generated method stub
				//创建时绘制背景
				drawBack(holder);
			}

			@Override
			public void surfaceDestroyed(SurfaceHolder arg0) {
				// TODO Auto-generated method stub
				//销毁计时器
				if(timer!=null){
					timer.cancel();
				}
			}		
		});  
        
        task=new TimerTask() {
			
			@Override
			public void run() {
				// TODO Auto-generated method stub
				//获取系统当前的时间
				Calendar c = Calendar.getInstance(); 
				int minutes=c.getTime().getMinutes();
				int seconds=c.getTime().getSeconds();
				int hours=c.getTime().getHours();
				
				Canvas canvas=s_hold.lockCanvas(new Rect(cx-radius+90,cy-radius+90,cx+radius-90,cy+radius-90));
				canvas.drawColor(Color.BLUE);
				drawMinutes(canvas,minutes);
				drawSeconds(canvas,seconds);
				drawHours(canvas,hours);
				s_hold.unlockCanvasAndPost(canvas);
				
			}

			private void drawHours(Canvas canvas, int hours) {
				// TODO Auto-generated method stub
				canvas.save();
				Paint p6=new Paint();
				p6.setColor(Color.RED);
				p6.setStyle(Paint.Style.FILL);
				p6.setStrokeWidth(5);
				canvas.rotate(360/12*hours,cx,cy);
				canvas.drawLine(cx,cy,cx,cy-90, p6);
				canvas.restore();
			}

			private void drawSeconds(Canvas canvas, int seconds) {
				// TODO Auto-generated method stub
				canvas.save();
				Paint p4=new Paint();
				p4.setColor(Color.GREEN);
				p4.setStyle(Paint.Style.FILL);
				p4.setStrokeWidth(2);
				canvas.rotate(360/COUNT*seconds,cx,cy);
				canvas.drawLine(cx,cy,cx,cy-130, p4);
				canvas.restore();
			}

			private void drawMinutes(Canvas canvas, int minutes) {
				// TODO Auto-generated method stub
				Paint p5=new Paint();
				p5.setColor(Color.YELLOW);
				p5.setStyle(Paint.Style.FILL);
				p5.setStrokeWidth(3);
				canvas.save();
				canvas.rotate(360/COUNT*minutes,cx,cy);
				canvas.drawLine(cx, cy, cx,cy-110, p5);
				canvas.restore();
			}
		};
		timer.schedule(task,1000,1000);
    }

    //绘制背景
    private void drawBack(SurfaceHolder holder){
    	//锁定SurfaceView画布
 	   Canvas canvas=holder.lockCanvas();
 	   //设置画布颜色
 	   canvas.drawColor(Color.BLUE);
 	   //画圆盘
 	   drawCircle(canvas,radius);
 	   //绘制文字
 	   drawText(canvas,radius,TEXT);
 	   //画刻度线
 	   drawDividing(canvas,radius);
 	   //解锁提交绘制
 	   holder.unlockCanvasAndPost(canvas);
 	   //holder.lockCanvas(new Rect(0,0,0,0));  
 	   //holder.unlockCanvasAndPost(canvas);  
    }

	private void  drawDividing(Canvas canvas, int radius) {
		// TODO Auto-generated method stub
		Paint p2=new Paint(paint);
		p2.setTextSize(20);
		for(int i=0;i<COUNT;i++){
			if(i%5==0){
				p2.setStrokeWidth(5);
				canvas.drawLine(cx,cy-radius,cx,cy-radius-20, p2);
				p2.setStrokeWidth(2);
				if(i==0){
					canvas.drawText(String.valueOf(12),cx-5,cy-radius-20-4, p2);
				}else{
					canvas.drawText(String.valueOf(i/5),cx-5,cy-radius-20-4, p2);
				}
			}else{
				p2.setStrokeWidth(3);
				canvas.drawLine(cx,cy-radius,cx,cy-radius-10, p2);
			}
			canvas.rotate(360/COUNT,cx,cy);
		}
	}

	private void drawText(Canvas canvas, int radius, String text) {
		// TODO Auto-generated method stub
		canvas.save();
		RectF rectf=new RectF(cx-radius+20,cy-radius+20,cx+radius-20,cy+radius-20);
		Path path=new Path();
		path.addArc(rectf,-180,359);
		Paint p1=new Paint(paint);
		p1.setStyle(Paint.Style.FILL);
		p1.setTextSize(20);
		p1.setStrokeWidth(1);
		canvas.drawTextOnPath(text, path,0,0, p1);
		canvas.restore();
	}

	private void drawCircle(Canvas canvas,int radius) {
		// TODO Auto-generated method stub
		paint=new Paint();
		paint.setAntiAlias(true);
		paint.setStyle(Paint.Style.STROKE);
		paint.setStrokeWidth(8);
		paint.setColor(Color.RED);
		canvas.drawCircle(cx,cy,radius, paint);	
	}
   

	@Override
	protected void onDestroy() {
		// TODO Auto-generated method stub
		super.onDestroy();
		if(timer!=null){
			timer.cancel();
		}
	}
}

</pre><pre name="code" class="java"><pre name="code" class="html"><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"
    >

    <SurfaceView
        android:id="@+id/sView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>