Android自定义控件系列之应用篇——圆形进度条

　　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：

 　　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);
        }
    }
}