public class HightLightTextView extends TextView {// 存储view的宽度  private int mTextViewWidth = 0;// 画笔  private Paint mPaint;// 线性渲染  private LinearGradient mLinearGradient;// 存储变换的matrix  private Matrix matrix;// 移动距离  private int mTranslateX = 0;// 构造方法  public HightLightTextView(Context context) {this(context, null);}public HightLightTextView(Context context, AttributeSet attrs) {this(context, attrs, 0);}public HightLightTextView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);}/*** view的调用过程:构造方法->onFinishInflate->onSizeChanged->onDraw*/@Overrideprotected void onSizeChanged(int w, int h, int oldw, int oldh) {super.onSizeChanged(w, h, oldw, oldh);// 获取view的宽度，初始化画笔等初始属性  if (mTextViewWidth == 0) {mTextViewWidth = getMeasuredWidth();// 如果宽度大于0的话，则初始化  if (mTextViewWidth > 0) {// 初始化画笔  mPaint = getPaint();// 线性渲染  mLinearGradient = new LinearGradient(0, getMeasuredHeight(), mTextViewWidth, 0,new int[]{0X55FFFFFF, 0XFFFFFFFF, 0X55FFFFFF},new float[]{0, 0.5f, 1}, Shader.TileMode.CLAMP);mPaint.setShader(mLinearGradient);matrix = new Matrix();}}}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);if (matrix != null) {mTranslateX += mTextViewWidth / 10;// 如果移动的距离大于两倍的宽度，则重新开始移动  if (mTranslateX > 2 * mTextViewWidth) {mTranslateX = -mTextViewWidth;}// 平移matrix  matrix.setTranslate(mTranslateX, 0);// 设置线性变化的matrix
            mLinearGradient.setLocalMatrix(matrix);// 延迟50ms重绘  (重绘时会重新调用onDraw)postInvalidateDelayed(50);}}}