【移动应用开发技术】Android中怎么实现截屏

【移动应用开发技术】Android中怎么实现截屏

本篇文章为大家展示了Android中怎么实现截屏，内容简明扼要并且容易理解，绝对能使你眼前一亮，通过这篇文章的详细介绍希望你能有所收获。普通截屏的实现获取当前Window的DrawingCache的方式，即decorView的DrawingCache/**

*

shot

the

current

screen

,with

the

status

but

the

status

is

trans

*

*

*

@param

ctx

current

activity

*/

public

static

Bitmap

shotActivity(Activity

ctx)

{

View

view

=

ctx.getWindow().getDecorView();

view.setDrawingCacheEnabled(true);

view.buildDrawingCache();

Bitmap

bp

=

Bitmap.createBitmap(view.getDrawingCache(),

0,

0,

view.getMeasuredWidth(),

view.getMeasuredHeight());

view.setDrawingCacheEnabled(false);

view.destroyDrawingCache();

return

bp;

}获取当前View的DrawingCachepublic

static

Bitmap

getViewBp(View

v)

{

if

(null

==

v)

{

return

null;

}

v.setDrawingCacheEnabled(true);

v.buildDrawingCache();

if

(Build.VERSION.SDK_INT

>=

11)

{

v.measure(MeasureSpec.makeMeasureSpec(v.getWidth(),

MeasureSpec.EXACTLY),

MeasureSpec.makeMeasureSpec(

v.getHeight(),

MeasureSpec.EXACTLY));

v.layout((int)

v.getX(),

(int)

v.getY(),

(int)

v.getX()

+

v.getMeasuredWidth(),

(int)

v.getY()

+

v.getMeasuredHeight());

}

else

{

v.measure(MeasureSpec.makeMeasureSpec(0,

MeasureSpec.UNSPECIFIED),

MeasureSpec.makeMeasureSpec(0,

MeasureSpec.UNSPECIFIED));

v.layout(0,

0,

v.getMeasuredWidth(),

v.getMeasuredHeight());

}

Bitmap

b

=

Bitmap.createBitmap(v.getDrawingCache(),

0,

0,

v.getMeasuredWidth(),

v.getMeasuredHeight());

v.setDrawingCacheEnabled(false);

v.destroyDrawingCache();

return

b;

}开源方案在滚动视图中，如果当前View并没有在视图中全部绘制出来，我们可以利用View的ScrollTo()和ScrollBy()方法来移动画布，同时获取当前View的可视部分的DrawingCache，最后进行拼接得到其Bitmap，参考:PGSSoft/scrollscreenshot@[Github]。Scrollview截屏三个截屏中，ScrollView最简单，因为ScrollView只有一个childView，虽然没有全部显示在界面上，但是已经全部渲染绘制，因此可以直接调用scrollView.draw(canvas)来完成截图public

static

Bitmap

shotScrollView(ScrollView

scrollView)

{

int

h

=

0;

Bitmap

bitmap

=

null;

for

(int

i

=

0;

i

<

scrollView.getChildCount();

i++)

{

h

+=

scrollView.getChildAt(i).getHeight();

scrollView.getChildAt(i).setBackgroundColor(Color.parseColor("#ffffff"));

}

bitmap

=

Bitmap.createBitmap(scrollView.getWidth(),

h,

Bitmap.Config.RGB_565);

final

Canvas

canvas

=

new

Canvas(bitmap);

scrollView.draw(canvas);

return

bitmap;

}Scrollview截屏而ListView就是会回收与重用Item，并且只会绘制在屏幕上显示的ItemView，根据stackoverflow上大神的建议，采用一个List来存储Item的视图，这种方案依然不够好，当Item足够多的时候，可能会发生oom。public

static

Bitmap

shotListView(ListView

listview)

{

ListAdapter

adapter

=

listview.getAdapter();

int

itemscount

=

adapter.getCount();

int

allitemsheight

=

0;

List<Bitmap>

bmps

=

new

ArrayList<Bitmap>();

for

(int

i

=

0;

i

<

itemscount;

i++)

{

View

childView

=

adapter.getView(i,

null,

listview);

childView.measure(

View.MeasureSpec.makeMeasureSpec(listview.getWidth(),

View.MeasureSpec.EXACTLY),

View.MeasureSpec.makeMeasureSpec(0,

View.MeasureSpec.UNSPECIFIED));

childView.layout(0,

0,

childView.getMeasuredWidth(),

childView.getMeasuredHeight());

childView.setDrawingCacheEnabled(true);

childView.buildDrawingCache();

bmps.add(childView.getDrawingCache());

allitemsheight

+=

childView.getMeasuredHeight();

}

Bitmap

bigbitmap

=

Bitmap.createBitmap(listview.getMeasuredWidth(),

allitemsheight,

Bitmap.Config.ARGB_8888);

Canvas

bigcanvas

=

new

Canvas(bigbitmap);

Paint

paint

=

new

Paint();

int

iHeight

=

0;

for

(int

i

=

0;

i

<

bmps.size();

i++)

{

Bitmap

bmp

=

bmps.get(i);

bigcanvas.drawBitmap(bmp,

0,

iHeight,

paint);

iHeight

+=

bmp.getHeight();

bmp.recycle();

bmp

=

null;

}

return

bigbitmap;

}RecyclerView截屏我们都知道，在新的Android版本中，已经可以用RecyclerView来代替使用ListView的场景，相比较ListView，RecyclerView对ItemView的缓存支持的更好。可以采用和ListView相同的方案，这里也是在stackoverflow上看到的方案。public

static

Bitmap

shotRecyclerView(RecyclerView

view)

{

RecyclerView.Adapter

adapter

=

view.getAdapter();

Bitmap

bigBitmap

=

null;

if

(adapter

!=

null)

{

int

size

=

adapter.getItemCount();

int

height

=

0;

Paint

paint

=

new

Paint();

int

iHeight

=

0;

final

int

maxMemory

=

(int)

(Runtime.getRuntime().maxMemory()

/

1024);

//

Use

1/8th

of

the

available

memory

for

this

memory

cache.

final

int

cacheSize

=

maxMemory

/

8;

LruCache<String,

Bitmap>

bitmaCache

=

new

LruCache<>(cacheSize);

for

(int

i

=

0;

i

<

size;

i++)

{

RecyclerView.ViewHolder

holder

=

adapter.createViewHolder(view,

adapter.getItemViewType(i));

adapter.onBindViewHolder(holder,

i);

holder.itemView.measure(

View.MeasureSpec.makeMeasureSpec(view.getWidth(),

View.MeasureSpec.EXACTLY),

View.MeasureSpec.makeMeasureSpec(0,

View.MeasureSpec.UNSPECIFIED));

holder.itemView.layout(0,

0,

holder.itemView.getMeasuredWidth(),

holder.itemView.getMeasuredHeight());

holder.itemView.setDrawingCacheEnabled(true);

holder.itemView.buildDrawingCache();

Bitmap

drawingCache

=

holder.itemView.getDrawingCache();

if

(drawingCache

!=

null)

{

bitmaCache.put(String.valueOf(i),

drawingCache);

}

height

+=

holder.itemView.getMeasuredHeight();

}

bigBitmap

=

Bitmap.createBitmap(view.getMeasuredWidth(),

height,

Bitmap.Config.ARGB_8888);

Canvas

bigCanvas

=

new

Canvas(bigBitmap);

Drawable

lBackground

=

view.getBackground();

if

(lBackground

instanceof

ColorDrawable)

{

ColorDrawable

lColorDrawable

=

(ColorDrawable)

lBackground;

int

lColor

=

lColorDrawable.getColor();

bigCanvas.drawColor(lColor);

}

for

(int

i

=

0;

i

<

size;

i++)

{

Bitmap

bitmap

=

bitmaCache.get(String.valueOf(i));

bigCanvas.drawBitmap(bitmap,

0f,

iHeight,

paint);

iHeight

+=

bitmap.getHeight();

bitmap.recycle();

}

}

return

bigBitmap;

}上面的方法在截取存在异步加载图片的RecyclerView时候会出现加载不出图片的情况,这里再补充一种滚动式截屏的方法public

static

void

screenShotRecycleView(final

RecyclerView

mRecyclerView,

final

RecycleViewRecCallback

callBack)

{

if

(mRecyclerView

==

null)

{

return;

}

BaseListFragment.MyAdapter

adapter

=

(BaseListFragment.MyAdapter)

mRecyclerView.getAdapter();

final

Paint

paint

=

new

Paint();

final

int

maxMemory

=

(int)

(Runtime.getRuntime().maxMemory()

/

1024);

//

Use

1/8th

of

the

available

memory

for

this

memory

cache.

final

int

cacheSize

=

maxMemory

/

8;

LruCache<String,

Bitmap>

bitmaCache

=

new

LruCache<>(cacheSize);

final

int

oneScreenHeight

=

mRecyclerView.getMeasuredHeight();

int

shotHeight

=

0;

if

(adapter

!=

null

&&

adapter.getData().size()

>

0)

{

int

headerSize

=

adapter.getHeaderLayoutCount();

int

dataSize

=

adapter.getData().size();

for

(int

i

=

0;

i

<

headerSize

+

dataSize;

i++)

{

BaseViewHolder

holder

=

(BaseViewHolder)

adapter.createViewHolder(mRecyclerView,

adapter.getItemViewType(i));

if

(i

>=

headerSize)

adapter.startConvert(holder,

adapter.getData().get(i

-

headerSize));

holder.itemView.measure(

View.MeasureSpec.makeMeasureSpec(mRecyclerView.getWidth(),

View.MeasureSpec.EXACTLY),

View.MeasureSpec.makeMeasureSpec(0,

View.MeasureSpec.UNSPECIFIED));

holder.itemView.layout(0,

0,

holder.itemView.getMeasuredWidth(),

holder.itemView.getMeasuredHeight());

holder.itemView.setDrawingCacheEnabled(true);

holder.itemView.buildDrawingCache();

Bitmap

drawingCache

=

holder.itemView.getDrawingCache();

//holder.itemView.destroyDrawingCache();//释放缓存占用的资源

if

(drawingCache

!=

null)

{

bitmaCache.put(String.valueOf(i),

drawingCache);

}

shotHeight

+=

holder.itemView.getHeight();

if

(shotHeight

>

12000)

{

//设置截图最大值

if

(callBack

!=

null)

callBack.onRecFinished(null);

return;

}

}

//添加底部高度(加载更多或loading布局高度,此处为固定值:)

final

int

footHight

=

Util.dip2px(mRecyclerView.getContext(),

42);

shotHeight

+=

footHight;

//返回到顶部

while

(mRecyclerView.canScrollVertically(-1))

{

mRecyclerView.scrollBy(0,

-oneScreenHeight);

}

//绘制截图的背景

final

Bitmap

bigBitmap

=

Bitmap.createBitmap(mRecyclerView.getMeasuredWidth(),

shotHeight,

Bitmap.Config.ARGB_8888);

final

Canvas

bigCanvas

=

new

Canvas(bigBitmap);

Drawable

lBackground

=

mRecyclerView.getBackground();

if

(lBackground

instanceof

ColorDrawable)

{

ColorDrawable

lColorDrawable

=

(ColorDrawable)

lBackground;

int

lColor

=

lColorDrawable.getColor();

bigCanvas.drawColor(lColor);

}

final

int[]

drawOffset

=

{0};

final

Canvas

canvas

=

new

Canvas();

if

(shotHeight

<=

oneScreenHeight)

{

//仅有一页

Bitmap

bitmap

=

Bitmap.createBitmap(mRecyclerView.getWidth(),

mRecyclerView.getHeight(),

Bitmap.Config.ARGB_8888);

canvas.setBitmap(bitmap);

mRecyclerView.draw(canvas);

if

(callBack

!=

null)

callBack.onRecFinished(bitmap);

}

else

{

//超过一页

final

int

finalShotHeight

=

shotHeight;

mRecyclerView.postDelayed(new

Runnable()

{

@Override

public

void

run()

{

if

((drawOffset[0]

+

oneScreenHeight

<

finalShotHeight))

{

//超过一屏

Bitmap

bitmap

=

Bitmap.createBitmap(mRecyclerView.getWidth(),

mRecyclerView.getHeight(),

Bitmap.Config.ARGB_8888);

canvas.setBitmap(bitmap);

mRecyclerView.draw(canvas);

bigCanvas.drawBitmap(bitmap,

0,

drawOffset[0],

paint);

drawOffset[0]

+=

oneScreenHeight;

mRecyclerView.scrollBy(0,

oneScreenHeight);

try

{

bitmap.recycle();

}

catch

(Exception

ex)

{

ex.printStackTrace();

}

mRecyclerView.postDelayed(this,

10);

}

else

{

//不足一屏时的处理

int

leftHeight

=

finalShotHeight

-

drawOffset[0]

-

footHight;

mRecyclerView.scrollBy(0,

leftHeight);

int

top

=

oneScreenHeight

-

(finalShotHeight

-

drawOffset[0]);

if

(top

>

0

&&

leftHeight

>

0)

{

Bitmap

bitmap

=

Bitmap.createBitmap(mRecyclerView.getWidth(),

mRecyclerView.getHeight(),

Bitmap.Config.ARGB_8888);

canvas.setBitmap(bitmap);

mRecyclerView.draw(canvas);

//截图,只要补足的那块图

bitmap

=

Bitmap.createBitmap(bitmap,

0,

top,

bitmap.getWidth(),

leftHeight,

null,

false);

bigCanvas.drawBitmap(bitmap,

0,

drawOffset[0],

paint);

try

{

bitmap.recycle();

}

catch

(Exception

ex)

{

ex.printStackTrace();

}

}

if

(callBack

!=

null)

callBack.onRecFinished(bigBitmap);

}

}

},

10);

}

}

}

public

interface

RecycleViewRecCallback

{

void

onRecFinished(Bitmap

bitmap);

}相信有不少小伙伴用BRVH第三方库来做recycleview的适配器的。使用这个库的话再用上面的方法会报角标越界的错误，看了BRVH的源码public

void

onBindViewHolder(ViewHolder

holder,

int

positions)

{

int

viewType

=

holder.getItemViewType();

switch(viewType)

{

case

0:

this.convert((BaseViewHolder)holder,

this.mData.get(holder.getLayoutPosition()

-

this.getHeaderLayoutCount()));

case

273:

case

819:

case

1365:

break;

case

546:

this.addLoadMore(holder);

break;

default:

this.convert((BaseViewHolder)holder,

this.mData.get(holder.getLayoutPosition()

-

this.getHeaderLayoutCount()));

this.onBindDefViewHolder((BaseViewHolder)holder,

this.mData.get(holder.getLayoutPosition()

-

this.getHeaderLayoutCount()));

}

}在调用adapter.onBindViewHolder时，因为里面的position参数未使用，里面用的计算holder.getLayoutPosition()-this.getHeaderLayoutCount()的值一直是-1导致角标越界报错。本人理解，RecyclerView的截屏原理是，首先构造每个item的ViewHolder，然后调用具体设置数据到每个item的方法，此时cache中就存有item的内容，此时绘制就能获取到完整的内容。采用v7包中的onBindViewHolder方法即可，或者是BRVH的convert方法，可以看到BRVH中没有暴露出这个方法，而且唯一暴露出的onBindViewHolder还会报角标越界错误，此时我们就需要在BRVH的基础上暴露出convert即可，代码如下public

class

MyAdapter

extends

BaseQuickAdapter<T>

{

public

MyAdapter()

{

super(getItemLayoutResId(),

datas);

}

/**

*

用于对外暴露convert方法,构造缓存视图(截屏用)

*

@param

viewHolder

*

@param

t

*/

public

void

startConvert(BaseViewHolder

viewHolder,

T

t){

convert(viewHolder,t);

}

@Override

protected

void

convert(BaseViewHolder

viewHolder,

T

t)

{

bindView(viewHolder,

t);

}

}然后将上面所述的获取Bitmap方法修改一下/**

*

截取recycler

view

*/

public

static

Bitmap

getRecyclerViewScreenshot(RecyclerView

view)

{

BaseListFragment.MyAdapter

adapter

=

(BaseListFragment.MyAdapter)

view.getAdapter();

Bitmap

bigBitmap

=

null;

if

(adapter

!=

null)

{

int

size

=

adapter.getData().size();

int

height

=

0;

Paint

paint

=

new

Paint();

int

iHeight

=

0;

final

int

maxMemory

=

(int)

(Runtime.getRuntime().maxMemory()

/

1024);

//

Use

1/8th

of

the

available

memory

for

this

memory

cache.

final

int

cacheSize

=

maxMemory

/

8;

LruCache<String,

Bitmap>

bitmaCache

=

new

LruCache<>(cacheSize);

for

(int

i

=

0;

i

<

size;

i++)

{

BaseViewHolder

holder

=

(BaseViewHolder)

adapter.createViewHolder(view,

adapter.getItemViewType(i));

//此处需要调用convert方法，否则绘制出来的都是空的item

adapter.startConvert(holder,

adapter.getData().get(i));

holder.itemView.measure(

View.MeasureSpec.makeMeasureSpec(view.getWidth(),

View.MeasureSpec.EXACTLY),

View.MeasureSpec.makeMeasureSpec(0,

View.MeasureSpec.UNSPECIFIED));

holder.itemView.layout(0,

0,

holder.itemView.getMeasuredWidth(),

holder.itemView.getMeasuredHeight());

holder.itemView.setDrawingCacheEnabled(true);

holder.itemView.buildDrawingCache();

Bitmap

drawingCache

=

holder.itemView.getDrawingCache();

if

(drawingCache

!=

null)

{

bitmaCache.put(String.valueOf(i),

drawingCache);

}

height

+=

holder.itemView.getMeasuredHeight();

}

bigBitmap

=

Bitmap.createBitmap(view.getMeasuredWidth(),

height,

Bitmap.Config.ARGB_8888);

Canvas

bigCanvas

=

new

Canvas(bigBitmap);

Drawable

lBackground

=

view.getBackground();

if

(lBackground

instanceof

ColorDrawable)

{

ColorDrawable

lColorDrawable

=

(ColorDrawable)

lBackground;

int

lColor

=

lColorDrawable.getColor();

bigCanvas.drawColor(lColor);

}

for

(int

i

=

0;

i

<

size;

i++)

{

Bitmap

bitmap

=

bitmaCache.get(String.valueOf(i));

bigCanvas.drawBitmap(bitmap,

0f,

iHeight,

paint);

iHeight

+=

bitmap.getHeight();

bitmap.recycle();

}

}

return

bigBitmap;

}合成Bitmap比如四张合成一张/**

*

将四张图拼成一张

*

*

@param

pic1

图一

*

@param

pic2

图二

*

@param

pic3

图三

*

@param

pic4

图四

*

@return

only_bitmap

*

详情见说明：{@link

com.bertadata.qxb.util.ScreenShotUtils}

*/

public

static

Bitmap

combineBitmapsIntoOnlyOne(Bitmap

pic1,

Bitmap

pic2,

Bitmap

pic3,

Bitmap

pic4,

Activity

context)

{

int

w_total

=

pic2.getWidth();

int

h_total

=

pic1.getHeight()

+

pic2.getHeight()

+

pic3.getHeight()

+

pic4.getHeight();

int

h_pic1

=

pic1.getHeight();

int

h_pic4

=

pic4.getHeight();

int

h_pic12

=

pic1.getHeight()

+

pic2.getHeight();

//此处为防止OOM需要对高度做限制

if

(h_total

>

HEIGHTLIMIT)

{

return

null;

}

Bitmap

only_bitmap

=

Bitmap.createBitmap(w_total,

h_total,

Bitmap.Config.ARGB_4444);

Canvas

canvas

=

new

Canvas(only_bitmap);

canvas.drawColor(ContextCompat.getColor(context,

R.color.color_content_bg));

canvas.drawBitmap(pic1,

0,

0,

null);

canvas.drawBitmap(pic2,

0,

h_pic1,

null);

canvas.drawBitmap(pic3,

0,

h_pic12,

null);

canvas.drawBitmap(pic4,

0,

h_total

-

h_pic4,

null);

return

only_bitmap;

}图片后期处理/**

*

将传入的Bitmap合理压缩后输出到系统截屏目录下

*

命名格式为：Screenshot+时间戳+启信宝报名.jpg

*

同时通知系统重新扫描系统文件

*

*

@param

pic1

图一

标题栏截图

*

@param

pic2

图二

scrollview截图

*

@param

context

用于通知重新扫描文件系统，为提升性能可去掉

*

详情见说明：{@link

com.bertadata.qxb.util.ScreenShotUtils}

*/

public

static

void

savingBitmapIntoFile(final

Bitmap

pic1,

final

Bitmap

pic2,

final

Activity

context,

final

BitmapAndFileCallBack

callBack)

{

if

(context

==

null

||

context.isFinishing())

{

return;

}

Thread

thread

=

new

Thread(new

Runnable()

{

@Override

public

void

run()

{

String

fileReturnPath

=

"";

int

w

=

pic1.getWidth();

Bitmap

bottom

=

BitmapFactory.decodeResource(context.getResources(),

R.drawable.ic_picture_combine_bottom);

Bitmap

top_banner

=

BitmapFactory.decodeResource(context.getResources(),

R.drawable.ic_picture_combine_top);

Bitmap

bitmap_bottom

=

anyRatioCompressing(bottom,

(float)

w

/

bottom.getWidth(),

(float)

w

/

bottom.getWidth());

Bitmap

bitmap_top

=

anyRatioCompressing(top_banner,

(float)

w

/

bottom.getWidth(),

(float)

w

/

bottom.getWidth());

final

Bitmap

only_bitmap

=

combineBitmapsIntoOnlyOne(bitmap_top,

pic1,

pic2,

bitmap_bottom,

context);

//

获取当前时间

SimpleDateFormat

sdf

=

new

SimpleDateFormat("yyyy-MM-dd-HH-mm-ss-ms",

Locale.getDefault());

String

data

=

sdf.format(new

Date());

//

获取内存路径

//

设置图片路径+命名规范

//

声明输出文件

String

storagePath

=

Environment.getExternalStorageDirectory().getAbsolutePath();

String

fileTitle

=

"Screenshot_"

+

data

+

"__info.jpg";

String

filePath

=

storagePath

+

"/DCIM/";

final

String

fileAbsolutePath

=

filePath

+

fileTitle;

File

file

=

new

File(fileAbsolutePath);

/**

*

质压与比压结合

*

分级压缩

*

输出文件

*/

if

(only_bitmap

!=

null)

{

try

{

//

首先，对原图进行一步质量压缩,形成初步文件

FileOutputStream

fos

=

new

FileOutputStream(file);

only_press(Bitmap.CompressFormat.JPEG,

50,

fos);

//

另建一个文件other_file预备输出

String

other_fileTitle

=

"Screenshot_"

+

data

+

"_com.bertadata.qxb.jpg";

String

other_fileAbsolutePath

=

filePath

+

other_fileTitle;

File

other_file

=

new

File(other_fileAbsolutePath);

FileOutputStream

other_fos

=

new

FileOutputStream(other_file);

//

其次，要判断质压之后的文件大小，按文件大小分级进行处理

long

file_size

=

file.length()

/

1024;

//

size

of

file(KB)

if

(file_size

<

0

||

!(file.exists()))

{

//

零级：

文件判空

throw

new

NullPointerException();

}

else

if

(file_size

>

0

&&

file_size

<=

256)

{

//

一级：

直接输出

deleteFile(other_file);

//

通知刷新文件系统，显示最新截取的图文件

fileReturnPath

=

fileAbsolutePath;

context.sendBroadcast(new

Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE,

Uri.parse("file://"

+

fileAbsolutePath)));

}

else

if

(file_size

>

256

&&

file_size

<=

768)

{

//

二级：

简单压缩:压缩为原比例的3/4，质压为50%

anyRatioCompressing(only_bitmap,

(float)

3

/

4,

(float)

3

/

4).compress(Bitmap.CompressFormat.JPEG,

40,

other_fos);

deleteFile(file);

//

通知刷新文件系统，显示最新截取的图文件

fileReturnPath

=

other_fileAbsolutePath;

context.sendBroadcast(new

Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE,

Uri.parse("file://"

+

other_fileAbsolutePath)));

}

else

if

(file_size

>

768

&&

file_size

<=

1280)

{

//

三级：

中度压缩：压缩为原比例的1/2，质压为40%

anyRatioCompressing(only_bitmap,

(float)

1

/

2,

(float)

1

/

2).compress(Bitmap.CompressFormat.