转载

Android自定义控件系列之应用篇——圆形进度条

一、概述

在上一篇博文中，我们给大家介绍了Android自定义控件系列的基础篇。链接： http://www.cnblogs.com/jerehedu/p/4360066.html

这一篇博文中，我们将在基础篇的基础上，再通过重写ondraw（）方法和自定义属性实现圆形进度条，效果如图所示：

二、实现步骤

1、编写自定义组件MyCircleProgress扩展View

public class MyCircleProgress extends View { …     }

2、在MyCircleProgress类中，定制属性

public int progress  = 0;//进度实际值,当前进度   /**    * 自定义控件属性，可灵活的设置圆形进度条的大小、颜色、类型等    */   private int mR;//圆半径，决定圆大小   private int bgColor;//圆或弧的背景颜色   private int fgColor;//圆或弧的前景颜色，即绘制时的颜色   private int drawStyle; //绘制类型 FILL画圆形进度条，STROKE绘制弧形进度条     private int strokeWidth;//STROKE绘制弧形的弧线的宽度   private int max;//最大值，设置进度的最大值 /**     * 设置进度，此为线程安全控件，由于考虑多线的问题，需要同步     */     public synchronized void setProgress(int progress) {    if(progress<0){     progress=0;    }else if(progress>max){     progress=max;    }else{     this.progress = progress;    }     }   public int getMax() {    return max; }

3、为定制的属性编写attrs.xml资源，该资源文件放在res/values目录下，内容如下：

<?xml version="1.0" encoding="utf-8"?> <resources>  <declare-styleable name="CircleProgressBar">   <attr name="bgColor" format="color"/>   <attr name="fgColor" format="color"/>   <attr name="r" format="integer"/>   <attr name="strokeWidth" format="integer"/>   <attr name="drawStyle">    <enum name="STROKE" value="0"></enum>    <enum name="FILL" value="1"></enum>   </attr>   <attr name="max" format="integer"/>  </declare-styleable> </resources>

4、在MyCircleProgress类中定义构造函数，初始化属性

private void initProperty(AttributeSet attrs){  TypedArray tArray = context.obtainStyledAttributes(attrs, R.styleable.CircleProgressBar);   mR=tArray.getInteger(R.styleable.CircleProgressBar_r,10);   bgColor=tArray.getColor(R.styleable.CircleProgressBar_bgColor, Color.GRAY);   fgColor=tArray.getColor(R.styleable.CircleProgressBar_fgColor, Color.RED);   drawStyle=tArray.getInt(R.styleable.CircleProgressBar_drawStyle, 0);   strokeWidth=tArray.getInteger(R.styleable.CircleProgressBar_strokeWidth, 10);   max=tArray.getInteger(R.styleable.CircleProgressBar_max, 100);  }  public MyCircleProgress(Context context, AttributeSet attrs) {   super(context, attrs);   this.context = context;   this.paint = new Paint();   this.paint.setAntiAlias(true); // 消除锯齿   this.paint.setStyle(Style.STROKE); // 绘制空心圆或 空心矩形   initProperty(attrs);   }

5、在MainActivity中布局文件中添加MyCircleProgress组件，如下所示

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" xmlns:app="http://schemas.android.com/apk/res/com.jereh.mydrawcircleprogress"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:paddingBottom="@dimen/activity_vertical_margin"     android:paddingLeft="@dimen/activity_horizontal_margin"     android:paddingRight="@dimen/activity_horizontal_margin"     android:paddingTop="@dimen/activity_vertical_margin"     tools:context=".MainActivity"      >     <com.jereh.views.MyCircleProgress   android:id="@+id/MyCircleProgress"   android:layout_width="wrap_content"   android:layout_height="wrap_content"    app:r="45"   app:strokeWidth="10"   app:bgColor="#cccccc"   app:fgColor="#ff0000"   app:drawStyle="FILL"   app:max="50"   /> </RelativeLayout>

6、自定义组件MyCircleProgress中重写onDraw方法：

protected  void onDraw(Canvas canvas) {  super.onDraw(canvas);  int center = getWidth() / 2; // 圆心位置  this.paint.setColor(bgColor);  this.paint.setStrokeWidth(strokeWidth);  canvas.drawCircle(center, center, mR, this.paint);  // 绘制圆环  this.paint.setColor(fgColor);  if(drawStyle==0){   this.paint.setStyle(Style.STROKE);   opt=false;  }else{   this.paint.setStyle(Style.FILL);   opt=true;  }  int top = (center - mR);  int bottom = (center + mR);  RectF oval = new RectF(top, top, bottom, bottom);  canvas.drawArc(oval, 270, 360*progress/max, opt, paint); }

7、编写MainActivity

public class MainActivity extends Activity {  private MyCircleProgress progressView;  @Override  protected void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   setContentView(R.layout.activity_main);   progressView = (MyCircleProgress) findViewById(R.id.MyCircleProgress);   new ProgressAnimation().execute();  }  class ProgressAnimation extends AsyncTask<Void, Integer, Void> {   @Override   protected Void doInBackground(Void... params) {    //进度值不断的变化    for (int i = 0; i < progressView.getMax(); i++) {     try {      publishProgress(i);      Thread.sleep(100);     } catch (InterruptedException e) {      e.printStackTrace();     }    }    return null;   }   @Override   protected void onProgressUpdate(Integer... values) {    //更新进度值    progressView.setProgress(values[0]);    progressView.invalidate();    super.onProgressUpdate(values);   }  } }