绕圈的兔子

      

       去年在学习了android基础后写了一个练习的小程序，本程序通过按钮来控制兔子的运动方向，兔子的运动方向有顺时针和逆时针兔子的运动的轨迹就是一个圆圈，有一个seekBar控制兔子运动的速度，点击开始按钮兔子开始运动，开始按钮隐藏，点击停止兔子停止运动，点击顺时针兔子按照顺时针方向运动，按钮文字变成逆时针字样！点击退出弹出对话框。

运行效果截图

1.布局文件activity_main.xml

<span style="font-size:14px;"><span style="font-size:14px;"><RelativeLayout 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:background="@drawable/background"    tools:context=".MainActivity" >    <RelativeLayout                                                             <!-- 此处先确定好下面按钮的布局 -->        android:layout_width="match_parent"        android:layout_height="100dp"        android:layout_alignParentBottom="true"        android:id="@+id/rel_below"        android:gravity="center"        >   <Button       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:id="@+id/startBtn"       android:text="@string/start"       ></Button>      <Button       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:id="@+id/stopBtn"       android:layout_toRightOf="@id/startBtn"       android:layout_marginLeft="10dp"       android:text="@string/stop"       ></Button>       <Button       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:id="@+id/anticBtn"       android:layout_toRightOf="@id/stopBtn"       android:layout_marginLeft="10dp"       android:text="@string/anticlockwise"       ></Button>         <Button       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:id="@+id/cloBtn"       android:visibility="gone"       android:layout_toRightOf="@id/anticBtn"       android:layout_marginLeft="10dp"       android:text="@string/clockwise"       ></Button>          <Button       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:layout_toRightOf="@id/cloBtn"       android:layout_marginLeft="10dp"       android:id="@+id/exitBtn"       android:text="@string/exit"       ></Button>     <SeekBar         android:layout_width="150dp"         android:layout_height="wrap_content"         android:layout_alignParentBottom="true"         android:layout_marginLeft="50dp"         android:max="40"         android:id="@+id/seekBar"         />    </RelativeLayout>    <RelativeLayout        android:layout_width="match_parent"        android:layout_height="fill_parent"        android:layout_above="@id/rel_below"        android:id="@+id/rel_above">     </RelativeLayout></RelativeLayout></span></span>

2.实体类Circle

<span style="font-size:14px;"><span style="font-size:14px;">package com.xg13.runRabbit6;import android.graphics.Canvas;import android.graphics.Paint;public class Circle {private float circle_x;              //圆心x轴坐标private float circle_y;              //圆心y轴坐标private float radius;                //半径private Paint paint;public Circle(Paint paint) {super();this.paint = paint;}public void draw(Canvas canvas){canvas.drawCircle(circle_x, circle_y, radius, paint);}public float getCircle_x() {return circle_x;}public void setCircle_x(float circle_x) {this.circle_x = circle_x;}public float getCircle_y() {return circle_y;}public void setCircle_y(float circle_y) {this.circle_y = circle_y;}public float getRadius() {return radius;}public void setRadius(float radius) {this.radius = radius;}public Paint getPaint() {return paint;}public void setPaint(Paint paint) {this.paint = paint;}}</span></span>

3.自定义的view类实现绘图测操作

<span style="font-size:14px;"><span style="font-size:14px;">package com.xg13.runRabbit6;import android.content.Context;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Canvas;import android.graphics.Paint;import android.graphics.Paint.Style;import static java.lang.Math.PI;import android.view.View;public class RunRabbitView extends View implements Runnable{private int canvas_width;           //画布的宽度private int canvas_height;          //画布的高度private Paint paint;                //画笔private Bitmap bitmap;              //位图private float image_width;          //图像的宽度private float image_height;         //图像的高度private Circle circle = null;private float rabbitChange_x;       //X轴方向的改变量private float rabbitChange_y;       //Y轴方向的改变量private float angle;private float angle_change =1;      //这里的角度改变量控制兔子运行的速度private boolean isRunning = false;private boolean isAntic = false;    /**     * @param context     */public RunRabbitView(Context context) {super(context);paint = new Paint();circle = new Circle(paint);bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.rabbit);image_width = bitmap.getWidth();image_height = bitmap.getHeight();}@Overrideprotected void onDraw(Canvas canvas) {// TODO Auto-generated method stubsuper.onDraw(canvas);circle.setCircle_x(canvas_width/2); circle.setCircle_y(canvas_height/2);circle.setRadius(canvas_width*3/10);paint.setStyle(Style.STROKE);paint.setAntiAlias(true);circle.draw(canvas);canvas.drawBitmap(bitmap, rabbitChange_x+circle.getCircle_x()-image_width/2, rabbitChange_y+circle.getCircle_y()-circle.getRadius()-image_height/2, paint);}//简单的三角函数就不用我再解释了吧public void jump(){rabbitChange_x = (float)Math.sin((PI*2*angle)/360)*circle.getRadius();rabbitChange_y = circle.getRadius() - (float)Math.cos((PI*2*angle)/360)*circle.getRadius();if(angle<=360){if(isAntic){angle -= angle_change;}else{angle += angle_change;}}else{angle -= 360;}}/** * 此处就是要获取页面加载后画布区域的实际的宽度和高度 */@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {// TODO Auto-generated method stubsuper.onMeasure(widthMeasureSpec, heightMeasureSpec);canvas_width = getMeasuredWidth();canvas_height = getMeasuredHeight();}@Overridepublic void run() {while(isRunning){           //此处设置了一个控制线程是否运行的标志jump();//向onDarw()发出重绘的请求postInvalidate();try {Thread.sleep(200);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}public void setRunning(boolean isRunning) {this.isRunning = isRunning;}public void setAntic(boolean isAntic) {this.isAntic = isAntic;}public float getAngle_change() {return angle_change;}public void setAngle_change(float angle_change) {this.angle_change = angle_change;}}</span></span>

4.主控制界面MainActivity类

<span style="font-size:14px;"><span style="font-size:14px;">import android.app.Activity;import android.app.AlertDialog;import android.content.DialogInterface;import android.os.Bundle;import android.view.View;import android.view.Window;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.RelativeLayout;import android.widget.SeekBar;import android.widget.SeekBar.OnSeekBarChangeListener;import android.widget.Toast;/** * @author 弓照鹏 * @since  2014-5-7 * @unit   xg12 */public class MainActivity extends Activity {private Button startBtn;         //开始按钮private Button stopBtn;          //停止按钮private Button anticBtn;         //逆时针按钮private Button cloBtn;           //顺时针按钮private Button exitBtn;          //退出按钮private SeekBar seekBar;private RunRabbitView runRabbit;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);requestWindowFeature(Window.FEATURE_NO_TITLE);setContentView(R.layout.activity_main);startBtn = (Button)findViewById(R.id.startBtn);stopBtn = (Button)findViewById(R.id.stopBtn);anticBtn = (Button)findViewById(R.id.anticBtn);cloBtn = (Button)findViewById(R.id.cloBtn);exitBtn = (Button)findViewById(R.id.exitBtn);seekBar = (SeekBar)findViewById(R.id.seekBar);seekBar.setOnSeekBarChangeListener(new SeekBarHandler());OnClickListener BtnHandler = new BtnHandler();startBtn.setOnClickListener(BtnHandler);stopBtn.setOnClickListener(BtnHandler);anticBtn.setOnClickListener(BtnHandler);cloBtn.setOnClickListener(BtnHandler);exitBtn.setOnClickListener(new ExitBtnHandler());runRabbit = new RunRabbitView(this);((RelativeLayout)this.findViewById(R.id.rel_above)).addView(runRabbit);}private class SeekBarHandler implements OnSeekBarChangeListener{@Overridepublic void onProgressChanged(SeekBar seekBar, int progress,boolean fromUser) {//此处设置角度的改变量runRabbit.setAngle_change(progress);}@Overridepublic void onStartTrackingTouch(SeekBar seekBar) {// TODO Auto-generated method stub}@Overridepublic void onStopTrackingTouch(SeekBar seekBar) {// TODO Auto-generated method stub}}private class BtnHandler implements OnClickListener{@Overridepublic void onClick(View v) {Thread tRabbit = new Thread(runRabbit,"绕圈兔子线程……");switch(v.getId()){case R.id.startBtn:startBtn.setVisibility(View.GONE);runRabbit.setRunning(true);tRabbit.start();break;case R.id.stopBtn:startBtn.setVisibility(View.VISIBLE);runRabbit.setRunning(false);break;case R.id.anticBtn:cloBtn.setVisibility(View.VISIBLE);anticBtn.setVisibility(View.GONE);runRabbit.setAntic(true);break;case R.id.cloBtn:anticBtn.setVisibility(View.VISIBLE);cloBtn.setVisibility(View.GONE);runRabbit.setAntic(false);break;}}}/* * 退出按钮的点击事件监听器 */private class ExitBtnHandler implements OnClickListener{@Overridepublic void onClick(View v) {DialogInterface.OnClickListener diaBtnHadler = new DiaBtnHadler();new AlertDialog.Builder(MainActivity.this)               .setIcon(R.drawable.question)               .setTitle("是否退出应用程序")           .setPositiveButton("确定", diaBtnHadler)           .setNegativeButton("取消", diaBtnHadler)           .setNeutralButton("忽略", diaBtnHadler)           .show();}}/* * 对话框按钮的点击事件监听器 */private class DiaBtnHadler implements android.content.DialogInterface.OnClickListener{@Overridepublic void onClick(DialogInterface dialog, int which) {switch(which){case DialogInterface.BUTTON_POSITIVE:MainActivity.this.finish();break;case DialogInterface.BUTTON_NEGATIVE:new AlertDialog.Builder(MainActivity.this).setMessage("我被调用了").show();break;case DialogInterface.BUTTON_NEUTRAL:Toast.makeText(MainActivity.this, "点击忽略了", Toast.LENGTH_LONG).show();break;default:break;}}}}</span></span>

       在代码里加入了比较详细的注释，大家可以自己看看，如果能独立的做出这个例子那么说明你对自定义view有了一个全新的认识，程序里面特别主要兔子绕圈时数学坐标的计算问题，和画布宽度和高度的值的获取！