【Android自定义控件】圆圈交替，仿progress效果

浏览数：23 / 时间：2015年06月11日

还是我们自定View的那几个步骤：

1、自定义View的属性

2、在View的构造方法中获得我们自定义的属性

3、重写onMesure （不是必须）

4、重写onDraw

自定义View的属性

 <?xml version="1.0" encoding="utf-8"?>
<resources>
<attr name="firstColor" format="color" />
    <attr name="secondColor" format="color" />
    <attr name="circleWidth" format="dimension" />
    <attr name="speed" format="integer" />

    <declare-styleable name="progressStyle">
        <attr name="firstColor"/>
        <attr name="secondColor"/>
        <attr name="circleWidth"/>
        <attr name="speed"/>
    </declare-styleable>
</resources>

自定义View，并且使用自定义的View

public class ProgressView extends View {

    /**
     * 第一圈的颜色
     */
    private int mFirstColor;
    /**
     * 第二圈的颜色
     */
    private int mSecondColor;
    /**
     * 圈的宽度
     */
    private int mCircleWidth;
    /**
     * 画笔
     */
    private Paint mPaint;
    /**
     * 当前进度
     */
    private int mProgress;

    /**
     * 速度
     */
    private int mSpeed;

    /**
     * 是否应该开始下一个
     */
    private boolean isNext = false;
    public ProgressView(Context context) {
        this(context, null);
    }

    public ProgressView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public ProgressView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        TypedArray typedArray = context.getTheme().obtainStyledAttributes(attrs, R.styleable.progressStyle,defStyleAttr,0);

        int n = typedArray.getIndexCount();

        for (int i =0 ;i < n ; i ++){
            int attr =typedArray.getIndex(i);
            switch (attr){//这里的0,1,2，3对应attrs中declare-styleable name="progressStyle"数组元素的顺序，我是为了举例方便，实际开发中不要这样写
                case 0:
                    mFirstColor = typedArray.getColor(attr, Color.BLACK);
                    break;
                case 1:
                    mSecondColor = typedArray.getColor(attr, Color.RED);
                    break;
                case 2:
                    mCircleWidth = typedArray.getDimensionPixelSize(attr,(int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP,
 16,getResources().getDisplayMetrics()));
                    break;
                case 3:
                    mSpeed = typedArray.getInt(attr,20);
                    break;
            }
        }
        typedArray.recycle();
        mPaint = new Paint();
        startMyThread();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        int center = getWidth() / 2; // 获取圆心的x坐标
        int radius = (center - mCircleWidth)/2 ;// 半径

        mPaint.setAntiAlias(true);
        mPaint.setStrokeWidth(mCircleWidth);
        mPaint.setStyle(Paint.Style.STROKE);

        RectF rectf = new RectF(center-radius,center-radius,center+radius,center+radius);
//颜色的切换
        if(!isNext){
            canvas.save();
            mPaint.setColor(mFirstColor);// 设置圆环的颜色
            canvas.drawCircle(center,center,radius,mPaint);//划出圆圈
            mPaint.setColor(mSecondColor);
            canvas.drawArc(rectf,-90,mProgress,false,mPaint);//根据进度画圆弧
            canvas.restore();
        }else {
            canvas.save();
            mPaint.setColor(mSecondColor);// 设置圆环的颜色
            canvas.drawCircle(center,center,radius,mPaint);
            mPaint.setColor(mFirstColor);
            canvas.drawArc(rectf,-90,mProgress,false,mPaint);
            canvas.restore();
        }
    }

    private void startMyThread() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                while (true){
                    mProgress++;//进度
                    if(mProgress == 360){//当360度时候值变为初始状态
                        mProgress = 0;

                        if(!isNext){//设置是否切换颜色开关
                            isNext = true;
                        }else {
                            isNext = false;
                        }

                    }

                    postInvalidate();

                    try {
                        Thread.sleep(mSpeed);
                    }catch (InterruptedException e){
                        e.printStackTrace();
                    }
                }
            }
        }).start();;
    }
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以上代码就是自定义View的全部代码，使用的话没什么多说的直接在Xml中引用这个新建的ProgressView就可以了

重画ondraw 不多解释直接看代码

 @Override
    protected void onDraw(Canvas canvas) {
        int center = getWidth() / 2; // 获取圆心的x坐标
        int radius = (center - mCircleWidth)/2 ;// 半径

        mPaint.setAntiAlias(true);
        mPaint.setStrokeWidth(mCircleWidth);
        mPaint.setStyle(Paint.Style.STROKE);

        RectF rectf = new RectF(center-radius,center-radius,center+radius,center+radius);

        if(!isNext){
            canvas.save();
            mPaint.setColor(mFirstColor);// 设置圆环的颜色
            canvas.drawCircle(center,center,radius,mPaint);//划出圆圈
            mPaint.setColor(mSecondColor);
            canvas.drawArc(rectf,-90,mProgress,false,mPaint);//根据进度画圆弧
            canvas.restore();
        }else {
            canvas.save();
            mPaint.setColor(mSecondColor);// 设置圆环的颜色
            canvas.drawCircle(center,center,radius,mPaint);
            mPaint.setColor(mFirstColor);
            canvas.drawArc(rectf,-90,mProgress,false,mPaint);
            canvas.restore();
        }
    }

效果是不是和progress相似呢，自己试试看吧