Android截屏

Android截屏的原理：获取具体需要截屏的区域的Bitmap，然后绘制在画布上，保存为图片后进行分享或者其它用途

一、Activity截屏

1、截Activity界面(包含空白的状态栏)

/**

* 根据指定的Activity截图(带空白的状态栏)

*

* @param context 要截图的Activity

* @return Bitmap

*/

public static Bitmap shotActivity(Activity context) {

View view = context.getWindow().getDecorView();

view.setDrawingCacheEnabled(true);

view.buildDrawingCache();

Bitmap bitmap = Bitmap.createBitmap(view.getDrawingCache(), 0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());

view.setDrawingCacheEnabled(false);

view.destroyDrawingCache();

return bitmap;

}

2、截Activity界面(去除状态栏)

/**

* 根据指定的Activity截图(去除状态栏)

*

* @param activity 要截图的Activity

* @return Bitmap

*/

public Bitmap shotActivityNoStatusBar(Activity activity) {

// 获取windows中最顶层的view

View view = activity.getWindow().getDecorView();

view.buildDrawingCache();

// 获取状态栏高度

Rect rect = new Rect();

view.getWindowVisibleDisplayFrame(rect);

int statusBarHeights = rect.top;

Display display = activity.getWindowManager().getDefaultDisplay();

// 获取屏幕宽和高

int widths = display.getWidth();

int heights = display.getHeight();

// 允许当前窗口保存缓存信息

view.setDrawingCacheEnabled(true);

// 去掉状态栏

Bitmap bmp = Bitmap.createBitmap(view.getDrawingCache(), 0,

statusBarHeights, widths, heights - statusBarHeights);

// 销毁缓存信息

view.destroyDrawingCache();

return bmp;

}

二、View截屏

/**

* 根据指定的view截图

*

* @param v 要截图的view

* @return Bitmap

*/

public static Bitmap getViewBitmap(View v) {

if (null == v) {

return null;

}

v.setDrawingCacheEnabled(true);

v.buildDrawingCache();

if (Build.VERSION.SDK_INT >= 11) {

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

View.MeasureSpec.makeMeasureSpec(v.getHeight(), View.MeasureSpec.EXACTLY));

v.layout((int) v.getX(), (int) v.getY(), (int) v.getX() + v.getMeasuredWidth(), (int) v.getY() + v.getMeasuredHeight());

} else {

v.measure(View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED),

View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));

v.layout(0, 0, v.getMeasuredWidth(), v.getMeasuredHeight());

}

Bitmap bitmap = Bitmap.createBitmap(v.getDrawingCache(), 0, 0, v.getMeasuredWidth(), v.getMeasuredHeight());

v.setDrawingCacheEnabled(false);

v.destroyDrawingCache();

return bitmap;

}

三、ScrollView截屏：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

/**

* Scrollview截屏

*

* @param scrollView 要截图的ScrollView

* @return Bitmap

*/

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;

}

四、ListView截屏：ListView是会回收与重用Item，并且只会绘制在屏幕上显示的ItemView，下面的方法采用一个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。

/**

* ListView截图

*

* @param listView 要截图的ListView

* @return Bitmap

*/

public static Bitmap shotListView(ListView listView) {

ListAdapter adapter = listView.getAdapter();

int itemsCount = adapter.getCount();

int allItemsHeight = 0;

ArrayList bmps = new ArrayList<>();

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;

}

五、RecycleView截屏

/**

* RecyclerView截屏

*

* @param view 要截图的RecyclerView

* @return Bitmap

*/

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 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;

}

六、WebView截屏

1、截取webView可视区域的截图

/**

* 截取webView可视区域的截图

* @param webView 前提：WebView要设置webView.setDrawingCacheEnabled(true);

* @return

*/

private Bitmap captureWebViewVisibleSize(WebView webView){

Bitmap bmp = webView.getDrawingCache();

return bmp;

}

2、截取webView的整个页面

/**

* 截取webView快照(webView加载的整个内容的大小)

* @param webView

* @return

*/

private Bitmap captureWebView(WebView webView){

Picture snapShot = webView.capturePicture();

Bitmap bmp = Bitmap.createBitmap(snapShot.getWidth(),snapShot.getHeight(), Bitmap.Config.ARGB_8888);

Canvas canvas = new Canvas(bmp);

snapShot.draw(canvas);

return bmp;

}

3、截取手机屏幕，获取界面展示的webview

/**

* 截屏

*

* @param context

* @return

*/

private Bitmap captureScreen(Activity context) {

View cv = context.getWindow().getDecorView();

Bitmap bmp = Bitmap.createBitmap(cv.getWidth(), cv.getHeight(), Bitmap.Config.ARGB_8888);

Canvas canvas = new Canvas(bmp);

cv.draw(canvas);

return bmp;

}

感谢阅读，希望能帮助到大家，谢谢大家对本站的支持！