【移动应用开发技术】Android SurfaceView预览变形怎么办

【移动应用开发技术】AndroidSurfaceView预览变形怎么办

这篇文章主要介绍了AndroidSurfaceView预览变形怎么办，具有一定借鉴价值，感兴趣的朋友可以参考下，希望大家阅读完这篇文章之后大有收获，下面让在下带着大家一起了解一下。这个问题百度上一搜一大把，基本上都是说找到和SurfaceView的比例相近的camera预览尺寸，但是发现预览时候还是差了点意思，具体看下面这个回调就知道是为什么了。

@Override

public

void

surfaceChanged(SurfaceHolder

holder,

int

format,

int

width,

int

height)

{

Log.i(TAG,

"surfaceChanged:

"

+

width

+

"

"

+

height);

}从上面的回调打印的数据知道其实取相近的比例解决不了根本问题。所以，对于此类的解决方法我只想说仅仅相近有神马用。那么既然知道surfaceChanged的宽高就是SurfaceView的渲染宽高，那么想办法把surfaceChanged里的宽高比弄成和camera比例一样不就行了嘛，所以看SurfaceView的源码：protected

void

updateWindow(boolean

force,

boolean

redrawNeeded)

{

...代码省略

int

myWidth

=

mRequestedWidth;

if

(myWidth

<=

0)

myWidth

=

getWidth();

int

myHeight

=

mRequestedHeight;

if

(myHeight

<=

0)

myHeight

=

getHeight();

...代码省略

if

(creating

||

formatChanged

||

sizeChanged

||

visibleChanged

||

realSizeChanged)

{

if

(DEBUG)

Log.i(TAG,

System.identityHashCode(this)

+

"

"

+

"surfaceChanged

--

format="

+

mFormat

+

"

w="

+

myWidth

+

"

h="

+

myHeight);

if

(callbacks

==

null)

{

callbacks

=

getSurfaceCallbacks();

}

for

(SurfaceHolder.Callback

c

:

callbacks)

{

c.surfaceChanged(mSurfaceHolder,

mFormat,

myWidth,

myHeight);

}

}

...代码省略

}可以看到宽高其实就是调用的View的getHeight和getWidth或者是mRequestedWidth和mRequestedHeight。熟悉了View的自定义就知道getHeight和getWidth都是和View的onMeasure息息相关，所以想到重写onMeasure方法。再从源码看到关于mRequestedWidth和mRequestedHeight的赋值@Override

public

void

setFixedSize(int

width,

int

height)

{

if

(mRequestedWidth

!=

width

||

mRequestedHeight

!=

height)

{

mRequestedWidth

=

width;

mRequestedHeight

=

height;

requestLayout();

}

}以下是完整类代码：public

class

ResizeAbleSurfaceView

extends

SurfaceView

{

private

int

mWidth

=

-1;

private

int

mHeight

=

-1;

public

ResizeAbleSurfaceView(Context

context)

{

super(context);

}

public

ResizeAbleSurfaceView(Context

context,

AttributeSet

attrs)

{

super(context,

attrs);

}

public

ResizeAbleSurfaceView(Context

context,

AttributeSet

attrs,

int

defStyleAttr)

{

super(context,

attrs,

defStyleAttr);

}

@Override

protected

void

onMeasure(int

widthMeasureSpec,

int

heightMeasureSpec)

{

if

(-1

==

mWidth

||

-1

==

mHeight)

{

super.onMeasure(widthMeasureSpec,

heightMeasureSpec);

}

else

{

setMeasuredDimension(mWidth,

mHeight);

}

}

public

void

resize(int

width,

int

height)

{

mWidth

=

width;

mHeight

=

height;

getHolder()