1.XML文件：

（1）.文字渐变核心类

public class ColorTrackView extends View {private int mTextStartX;private int mTextStartY;public enum Direction {LEFT, RIGHT, TOP, BOTTOM;}private int mDirection = DIRECTION_LEFT;private static final int DIRECTION_LEFT = 0;private static final int DIRECTION_RIGHT = 1;private static final int DIRECTION_TOP = 2;private static final int DIRECTION_BOTTOM = 3;public void setDirection(int direction) {mDirection = direction;}private String mText = "";private Paint mPaint;private int mTextSize = sp2px(30);private int mTextOriginColor = 0xff000000;private int mTextChangeColor = 0xffff0000;private Rect mTextBound = new Rect();private int mTextWidth;private int mTextHeight;private float mProgress;public ColorTrackView(Context context) {super(context, null);}public ColorTrackView(Context context, AttributeSet attrs) {super(context, attrs);mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);TypedArray ta = context.obtainStyledAttributes(attrs,R.styleable.ColorTrackView);mText = ta.getString(R.styleable.ColorTrackView_text);mTextSize = ta.getDimensionPixelSize(R.styleable.ColorTrackView_text_size, mTextSize);mTextOriginColor = ta.getColor(R.styleable.ColorTrackView_text_origin_color, mTextOriginColor);mTextChangeColor = ta.getColor(R.styleable.ColorTrackView_text_change_color, mTextChangeColor);mProgress = ta.getFloat(R.styleable.ColorTrackView_progress, 0);mDirection = ta.getInt(R.styleable.ColorTrackView_direction, mDirection);ta.recycle();mPaint.setTextSize(mTextSize);}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {measureText();int width = measureWidth(widthMeasureSpec);int height = measureHeight(heightMeasureSpec);setMeasuredDimension(width, height);mTextStartX = getMeasuredWidth() / 2 - mTextWidth / 2;mTextStartY = getMeasuredHeight() / 2 - mTextHeight / 2;}private int measureHeight(int measureSpec) {int mode = MeasureSpec.getMode(measureSpec);int val = MeasureSpec.getSize(measureSpec);int result = 0;switch (mode) {case MeasureSpec.EXACTLY:result = val;break;case MeasureSpec.AT_MOST:case MeasureSpec.UNSPECIFIED:result = mTextBound.height();result += getPaddingTop() + getPaddingBottom();break;}result = mode == MeasureSpec.AT_MOST ? Math.min(result, val) : result;return result;}private int measureWidth(int measureSpec) {int mode = MeasureSpec.getMode(measureSpec);int val = MeasureSpec.getSize(measureSpec);int result = 0;switch (mode) {case MeasureSpec.EXACTLY:result = val;break;case MeasureSpec.AT_MOST:case MeasureSpec.UNSPECIFIED:// result = mTextBound.width();result = mTextWidth;result += getPaddingLeft() + getPaddingRight();break;}result = mode == MeasureSpec.AT_MOST ? Math.min(result, val) : result;return result;}private void measureText() {mTextWidth = (int) mPaint.measureText(mText);FontMetrics fm = mPaint.getFontMetrics();mTextHeight = (int) Math.ceil(fm.descent - fm.top);mPaint.getTextBounds(mText, 0, mText.length(), mTextBound);mTextHeight = mTextBound.height();}public void reverseColor() {int tmp = mTextOriginColor;mTextOriginColor = mTextChangeColor;mTextChangeColor = tmp;}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);int r = (int) (mProgress * mTextWidth + mTextStartX);int t = (int) (mProgress * mTextHeight + mTextStartY);if (mDirection == DIRECTION_LEFT) {drawChangeLeft(canvas, r);drawOriginLeft(canvas, r);} else if (mDirection == DIRECTION_RIGHT) {drawOriginRight(canvas, r);drawChangeRight(canvas, r);} else if (mDirection == DIRECTION_TOP) {drawOriginTop(canvas, t);drawChangeTop(canvas, t);} else {drawOriginBottom(canvas, t);drawChangeBottom(canvas, t);}}private boolean debug = false;private void drawText_h(Canvas canvas, int color, int startX, int endX) {mPaint.setColor(color);if (debug) {mPaint.setStyle(Style.STROKE);canvas.drawRect(startX, 0, endX, getMeasuredHeight(), mPaint);}canvas.save(Canvas.CLIP_SAVE_FLAG);canvas.clipRect(startX, 0, endX, getMeasuredHeight());// left, top,// right, bottomcanvas.drawText(mText, mTextStartX,getMeasuredHeight() / 2- ((mPaint.descent() + mPaint.ascent()) / 2), mPaint);canvas.restore();}private void drawText_v(Canvas canvas, int color, int startY, int endY) {mPaint.setColor(color);if (debug) {mPaint.setStyle(Style.STROKE);canvas.drawRect(0, startY, getMeasuredWidth(), endY, mPaint);}canvas.save(Canvas.CLIP_SAVE_FLAG);canvas.clipRect(0, startY, getMeasuredWidth(), endY);// left, top,canvas.drawText(mText, mTextStartX,getMeasuredHeight() / 2- ((mPaint.descent() + mPaint.ascent()) / 2), mPaint);canvas.restore();}private void drawChangeLeft(Canvas canvas, int r) {drawText_h(canvas, mTextChangeColor, mTextStartX,(int) (mTextStartX + mProgress * mTextWidth));}private void drawOriginLeft(Canvas canvas, int r) {drawText_h(canvas, mTextOriginColor, (int) (mTextStartX + mProgress* mTextWidth), mTextStartX + mTextWidth);}private void drawChangeRight(Canvas canvas, int r) {drawText_h(canvas, mTextChangeColor,(int) (mTextStartX + (1 - mProgress) * mTextWidth), mTextStartX+ mTextWidth);}private void drawOriginRight(Canvas canvas, int r) {drawText_h(canvas, mTextOriginColor, mTextStartX,(int) (mTextStartX + (1 - mProgress) * mTextWidth));}private void drawChangeTop(Canvas canvas, int r) {drawText_v(canvas, mTextChangeColor, mTextStartY,(int) (mTextStartY + mProgress * mTextHeight));}private void drawOriginTop(Canvas canvas, int r) {drawText_v(canvas, mTextOriginColor, (int) (mTextStartY + mProgress* mTextHeight), mTextStartY + mTextHeight);}private void drawChangeBottom(Canvas canvas, int t) {drawText_v(canvas, mTextChangeColor,(int) (mTextStartY + (1 - mProgress) * mTextHeight),mTextStartY + mTextHeight);}private void drawOriginBottom(Canvas canvas, int t) {drawText_v(canvas, mTextOriginColor, mTextStartY,(int) (mTextStartY + (1 - mProgress) * mTextHeight));}public float getProgress() {return mProgress;}public void setProgress(float progress) {this.mProgress = progress;invalidate();}public int getTextSize() {return mTextSize;}public void setTextSize(int mTextSize) {this.mTextSize = mTextSize;mPaint.setTextSize(mTextSize);requestLayout();invalidate();}public void setText(String text) {this.mText = text;requestLayout();invalidate();}public int getTextOriginColor() {return mTextOriginColor;}public void setTextOriginColor(int mTextOriginColor) {this.mTextOriginColor = mTextOriginColor;invalidate();}public int getTextChangeColor() {return mTextChangeColor;}public void setTextChangeColor(int mTextChangeColor) {this.mTextChangeColor = mTextChangeColor;invalidate();}private int dp2px(float dpVal) {return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,dpVal, getResources().getDisplayMetrics());}private int sp2px(float dpVal) {return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP,dpVal, getResources().getDisplayMetrics());}private static final String KEY_STATE_PROGRESS = "key_progress";private static final String KEY_DEFAULT_STATE = "key_default_state";@Overrideprotected Parcelable onSaveInstanceState() {Bundle bundle = new Bundle();bundle.putFloat(KEY_STATE_PROGRESS, mProgress);bundle.putParcelable(KEY_DEFAULT_STATE, super.onSaveInstanceState());return bundle;}@Overrideprotected void onRestoreInstanceState(Parcelable state) {if (state instanceof Bundle) {Bundle bundle = (Bundle) state;mProgress = bundle.getFloat(KEY_STATE_PROGRESS);super.onRestoreInstanceState(bundle.getParcelable(KEY_DEFAULT_STATE));return;}super.onRestoreInstanceState(state);}}

mTabs.add(microcontest_first);mTabs.add(microcontest_second);

        microcontest_first = (ColorTrackView) findViewById(R.id.microcontest_first);        microcontest_second = (ColorTrackView) findViewById(R.id.microcontest_second);

        mTabs.add(microcontest_second);

 /**     * 设置滑动条的宽度为屏幕的1/2(根据Tab的个数而定)     */    private void initTabLineWidth() {        DisplayMetrics dpMetrics = new DisplayMetrics();        getWindow().getWindowManager().getDefaultDisplay()                .getMetrics(dpMetrics);        screenWidth = dpMetrics.widthPixels;        LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) microcontest_tab_img                .getLayoutParams();        lp.width = screenWidth / 2;        microcontest_tab_img.setLayoutParams(lp);    }

 /**     * 初始化页卡内容区     */    private void initViewPager() {        microcontest_vp.setAdapter(new MicroContestVPAdapter(getSupportFragmentManager(), fragmentArrayList));        //让ViewPager缓存2个页面        microcontest_vp.setOffscreenPageLimit(2);        //设置默认打开第一页        microcontest_vp.setCurrentItem(0);        //设置viewpager页面滑动监听事件        microcontest_vp.setOnPageChangeListener(new MyOnPageChangeListener());    }

 /**     * 页卡切换监听     *     * @author weizhi     * @version 1.0     */    public class MyOnPageChangeListener implements ViewPager.OnPageChangeListener {        @Override        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {            LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) microcontest_tab_img                    .getLayoutParams();            if (currIndex == 0 && position == 0)// 0->1            {                lp.leftMargin = (int) (positionOffset * (screenWidth * 1.0 / 2) + currIndex                        * (screenWidth / 2));            } else if (currIndex == 1 && position == 0) // 1->0            {                lp.leftMargin = (int) (-(1 - positionOffset)                        * (screenWidth * 1.0 / 2) + currIndex                        * (screenWidth / 2));            }            microcontest_tab_img.setLayoutParams(lp);            if (positionOffset > 0) {                ColorTrackView left = mTabs.get(position);                ColorTrackView right = mTabs.get(position + 1);                left.setDirection(1);                right.setDirection(0);                Log.e("TAG", positionOffset + "");                left.setProgress(1 - positionOffset);                right.setProgress(positionOffset);            }        }        @Override        public void onPageSelected(int position) {        }        @Override        public void onPageScrollStateChanged(int state) {        }    }