//创建一个空的PathMeasure
public PathMeasure()
//创建 PathMeasure 并关联一个指定的Path(Path需要已经创建完成)。
public PathMeasure(Path path, boolean forceClosed)
public void setPath(Path path, boolean forceClosed)
public boolean isClosed()
public float getLength()
public boolean nextContour()
public boolean getSegment(float startD, float stopD, Path dst, boolean startWithMoveTo)
public boolean getPosTan(float distance, float pos[], float tan[])
public boolean getMatrix(float distance, Matrix matrix, int flags)