Android自定義View實(shí)現(xiàn)可拖拽的進(jìn)度條

    @Override    protected void onSizeChanged(int w, int h, int oldw, int oldh) {        super.onSizeChanged(w, h, oldw, oldh);        //進(jìn)度條繪制在控件中央,寬度為控件寬度(mProgressHeight/2是為了顯示出左右兩邊的圓角)        mPathProgressBg.moveTo(mProgressHeight / 2,h / 2f);        mPathProgressBg.lineTo(w - mProgressHeight / 2,h / 2f);        //將進(jìn)度條路徑設(shè)置給PathMeasure        mPathMeasure.setPath(mPathProgressBg,false);        invalidate();    }

private void drawProgress(Canvas canvas) {        mPathProgressFg.reset();        mPaintProgress.setColor(mColorProgressBg);        //繪制進(jìn)度背景        canvas.drawPath(mPathProgressBg, mPaintProgress);        //計(jì)算進(jìn)度條的進(jìn)度        float stop = mPathMeasure.getLength() * mProgress;        //得到與進(jìn)度對(duì)應(yīng)的路徑        mPathMeasure.getSegment(0,stop,mPathProgressFg,true);        mPaintProgress.setColor(mColorProgressFg);        //繪制進(jìn)度        canvas.drawPath(mPathProgressFg, mPaintProgress);    }

private void drawShowProgressRoundRect(Canvas canvas) {        float stop = mPathMeasure.getLength() * mProgress;//計(jì)算進(jìn)度條的進(jìn)度        //根據(jù)要繪制的文字的最大長(zhǎng)寬來(lái)計(jì)算要繪制的圓角矩形的長(zhǎng)寬        Rect rect = new Rect();        mPaintProgressText.getTextBounds(mProgressMaxText,0, mProgressMaxText.length(),rect);        //要繪制矩形的寬、高        float rectWidth = rect.width() + (mProgressStrMarginH * 2);        float rectHeight = rect.height() + (mProgressStrMarginV * 2);        //計(jì)算邊界值（為了不讓矩形在左右兩邊超出邊界）        if(stop < rectWidth / 2f){            stop = rectWidth / 2f;        }else if(stop > (getWidth() - rectWidth / 2f)){            stop = getWidth() - rectWidth / 2f;        }        //定義繪制的矩形        float left = stop - rectWidth / 2f;        float right = stop + rectWidth / 2f;        float top = getHeight() / 2f - rectHeight / 2f;        float bottom = getHeight() / 2f + rectHeight / 2f;        mProgressRoundRectF = new RectF(left,top,right,bottom);        //繪制為圓角矩形        canvas.drawRoundRect(mProgressRoundRectF, mRoundRectRadius, mRoundRectRadius,mPaintRoundRect);    }

private void drawProgressText(Canvas canvas) {        String progressText = (int)Math.floor(100 * mProgress) + "%";        //讓文字垂直居中的偏移        int offsetY = (mFontMetricsInt.bottom - mFontMetricsInt.ascent) / 2 - mFontMetricsInt.bottom;        //將文字繪制在矩形的中央        canvas.drawText(progressText,mProgressRoundRectF.centerX(),mProgressRoundRectF.centerY() + offsetY,mPaintProgressText);    }

    @Override    public boolean onTouchEvent(MotionEvent event) {        switch (event.getAction()){            case MotionEvent.ACTION_DOWN:                //判斷手指是否觸摸了顯示進(jìn)度的圓角矩形塊，這樣才可以拖拽                if(mProgressRoundRectF != null && mProgressRoundRectF.contains(event.getX(),event.getY())){                    //記錄手指剛接觸屏幕的X軸坐標(biāo)（因?yàn)橹恍枰赬軸上平移）                    mStartTouchX = event.getX();                    mIsTouchSeek = true;                }                break;            case MotionEvent.ACTION_MOVE:                if(mIsTouchSeek){                    //計(jì)算橫向移動(dòng)的距離                    float moveX = event.getX() - mStartTouchX;                    //計(jì)算出當(dāng)前進(jìn)度的X軸所顯示的進(jìn)度長(zhǎng)度                    float currentProgressWidth = mPathMeasure.getLength() * mProgress;//計(jì)算進(jìn)度條的進(jìn)度                    //計(jì)算滑動(dòng)后的X軸的坐標(biāo)                    float showProgressWidth = currentProgressWidth + moveX;                    //計(jì)算邊界值                    if(showProgressWidth < 0){                        showProgressWidth = 0;                    }else if(showProgressWidth > mPathMeasure.getLength()){                        showProgressWidth = mPathMeasure.getLength();                    }                    //計(jì)算滑動(dòng)后的進(jìn)度                    mProgress = showProgressWidth / mPathMeasure.getLength();                    //重繪                    invalidate();                    //刷新用于計(jì)算移動(dòng)的X軸坐標(biāo)                    mStartTouchX = event.getX();                }                break;            case MotionEvent.ACTION_UP:                mIsTouchSeek = false;                break;        }        return mIsTouchSeek;    }

 @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        setMeasuredDimension(measureSizeWidth(widthMeasureSpec), measureSizeHeight(heightMeasureSpec));    }
    //計(jì)算寬度    private int measureSizeWidth(int size) {        int mode = MeasureSpec.getMode(size);        int s = MeasureSpec.getSize(size);        if (mode == MeasureSpec.EXACTLY) {            return s;        } else{            return Math.min(s, 200);        }    }    //計(jì)算高度    private int measureSizeHeight(int size) {        int mode = MeasureSpec.getMode(size);        int s = MeasureSpec.getSize(size);        if (mode == MeasureSpec.EXACTLY) {            return s;        }else {            //自適應(yīng)模式，返回所需的最小高度            return (int) (mTextSize + mProgressStrMarginV * 2);        }    }