【移动应用开发技术】Android如何实现自定义View图片按Path运动和旋转效果

【移动应用开发技术】Android如何实现自定义View图片按Path运动和旋转效果

/upload/information/20200623/125/124344.gif/**

*

author

:

stone

*

email

:

aa86799@163.com

*

time

:

16/5/29

15

29

*/

public

class

EarthPathView

extends

View

{

private

Path

mPath;

private

Paint

mPaint;

private

Bitmap

mBitmap;

private

PathMeasure

mPathMeasure;

private

float[]

mPoint;

private

float[]

mTan;

private

float

mDdegrees;

public

EarthPathView(Context

context)

{

this(context,

null);

}

public

EarthPathView(Context

context,

AttributeSet

attrs)

{

this(context,

attrs,

0);

}

public

EarthPathView(Context

context,

AttributeSet

attrs,

int

defStyleAttr)

{

super(context,

attrs,

defStyleAttr);

mPaint

=

new

Paint();

mPaint.setColor(Color.RED);

mPaint.setStyle(Paint.Style.STROKE);

mPaint.setStrokeWidth(10);

InputStream

is

=

getResources().openRawResource(R.drawable.earth);

mBitmap

=

BitmapFactory.decodeStream(is);

}

public

void

setPath(Path

path)

{

mPath

=

path;

mPathMeasure

=

new

PathMeasure(path,

false);

mPoint

=

new

float[2];

mTan

=

new

float[2];

}

@Override

protected

void

onDraw(Canvas

canvas)

{

super.onDraw(canvas);

if

(mPath

==

null)

{

return;

}

canvas.rotate(mDdegrees+=2,

getWidth()/2,

getHeight()/2);

canvas.drawPath(mPath,

mPaint);

float

degress

=

(float)

Math.toDegrees(Math.atan2(mTan[1],

mTan[0]));

Matrix

matrix

=

new

Matrix();

matrix.postRotate(degress,

mBitmap.getWidth()

/

2,

mBitmap.getHeight()

/

2);

matrix.postTranslate(mPoint[0]

-

mBitmap.getWidth()

/

2,

mPoint[1]

-

mBitmap.getHeight()

/

2);

canvas.drawBitmap(mBitmap,

matrix,

null);

}

@TargetApi(Build.VERSION_CODES.HONEYCOMB)

public

void

startAnim()

{

ValueAnimator

animator

=

ValueAnimator.ofFloat(0,

mPathMeasure.getLength());

animator.setDuration(2000);

animator.setInterpolator(new

LinearInterpolator());

//插值器

animator.setRepeatCount(ValueAnimator.INFINITE);

animator.addUpdateListener(new

ValueAnimator.AnimatorUpdateListener()

{

@Override

public

void

onAnimationUpdate(ValueAnimator

animation)

{

float

distance

=

(float)

animation.getAnimatedValue();

mPathMeasure.getPosTan(distance,

mPoint,

mTan);

invalidate();

}

});

animator.start();

}

}Activitypackage

com.stone.canvaspath;

import

android.app.Activity;

import

android.graphics.Path;

import

android.os.Bundle;

import

com.stone.canvaspath.earth.EarthPathView;

/**

*

author

:

stone

*

email

:

aa86799@163.com

*

time

:

16/5/29

15

27

*/

public

class

EarthActivity

extends

Activity

{

private

EarthPathView

mPathView;

private

Path

mPath;

@Override

protected

void

onCreate(Bundle

savedInstanceState)

{

super.onCreate(savedInstanceState);

int

w

=

getResources().getDisplayMetrics().widthPixels;

int

h

=

getResources().getDisplayMetrics().heightPixels;

mPathView

=

new

EarthPathView(this);

setContentView(mPathView);

int

min

=

Math.min(w,

h);

buildPath(w

/

2

+

100,

h

/

2

+

100,

min

/

4);

mPathView.setPath(mPath);

mPathView.s