Android|Android 把View转为图片
在开发的过程中有时会碰到这样的需求，把一个activity或者一个view变成图片分享出去。从网上收集了一些资料之后经过整理现在分享出来，教大家实现activity，scrollview，listview，recycleview，画中画以及在后台把layout生成图片的方法。如有侵权的地方，请及时告诉我改正，谢谢。
代码在这里 https://github.com/iotxc/ScreenShootDemo
在贴方法之前我要提醒大家注意一点，view中有图片的，如果是本地图片那么网上的代码你拿过来直接用就行了，如果是根据url加载的你要注意了，直接写Glide.with(this).load(url).into(imageview);
你得到的将会是一片空白，要使用simpleTarget的回调加载图片才行
Glide.with(this)
.load(url)
.asBitmap()
.into(new SimpleTarget() {
@Override
public void onResourceReady(Bitmap resource, GlideAnimation glideAnimation) {
imageview.setImageBitmap(resource);
}
});
具体是为什么我还不清楚。
screenshoot.gif
我也不知道视频为什么会这么模糊，凑合看一下吧= =，有知道怎么做的清晰点的请留言告诉我
1. activity截图
/**
* 获取指定Activity的截屏
*/
public static Bitmap activityScreenShot(Activity activity) {
// View是你需要截图的View
View view = activity.getWindow().getDecorView();
view.setDrawingCacheEnabled(true);
view.buildDrawingCache();
Bitmap bitmap = view.getDrawingCache();
// 获取状态栏高度
Rect frame = new Rect();
activity.getWindow().getDecorView().getWindowVisibleDisplayFrame(frame);
int statusBarHeight = frame.top;
// 获取屏幕长和高
int width = activity.getWindowManager().getDefaultDisplay().getWidth();
int height = activity.getWindowManager().getDefaultDisplay().getHeight();
// 去掉标题栏
Bitmap b = Bitmap.createBitmap(bitmap, 0, statusBarHeight, width, height - statusBarHeight);
view.destroyDrawingCache();
return b;
}
2. scrollview截图
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/**
* 获取scrollview的截屏
*/
public static Bitmap scrollViewScreenShot(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;
}
【Android|Android 把View转为图片】3. listview截图
因为listview布局复用的问题并且只能绘制在屏幕上显示的ItemView，所以我们需要把它的item放到一个view的集合里最后通过拼接来完成整图的效果。但是当Item足够多的时候，肯定会发生oom的所以记得在获得bitmap之后对其进行压缩处理。
/**
* 获取listview的截屏
* @param listview
* @return
*/
public static Bitmap shotListView(ListView listview) {
ListAdapter adapter = listview.getAdapter();
int itemscount = adapter.getCount();
int allitemsheight = 0;
List bmps = new ArrayList();
//循环对listview的item进行截图， 最后拼接在一起
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();
//这里可以把listview中单独的item进行保存
//viewSaveToImage(childView.getDrawingCache());
}
int w = listview.getMeasuredWidth();
Bitmap bigbitmap = Bitmap.createBitmap(w, 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;
}
4. recycleview截图
recycleview和listView使用相同的方案
/**
* recycleview截图
* @param view
* @return
*/
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;
}
5. 任意View转bitmap
/**
* view转bitmap
*/
public Bitmap viewConversionBitmap(View v) {
int w = v.getWidth();
int h = v.getHeight();
Bitmap bmp = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(bmp);
c.drawColor(Color.WHITE);
/** 如果不设置canvas画布为白色，则生成透明 */v.layout(0, 0, w, h);
v.draw(c);
return bmp;
}
注意：这里的view只能是已经显示在界面上的，那没显示在界面上的怎么处理？往下看
此方法也是后台生成view的方法：
/**
* 计算view的大小
*/
public void measureSize(Activity activity, String url) {
//将布局转化成view对象
View viewBitmap = LayoutInflater.from(activity).inflate(R.layout.background_layout, null);
WindowManager manager = activity.getWindowManager();
DisplayMetrics outMetrics = new DisplayMetrics();
manager.getDefaultDisplay().getMetrics(outMetrics);
int width = outMetrics.widthPixels;
int height = outMetrics.heightPixels;
//然后View和其内部的子View都具有了实际大小，也就是完成了布局，相当与添加到了界面上。接着就可以创建位图并在上面绘制了：
layoutView(viewBitmap, width, height, url, activity);
}/**
* 填充布局内容
*/
public void layoutView(final View viewBitmap, int width, int height, String url, Activity activity) {
// 整个View的大小 参数是左上角 和右下角的坐标
viewBitmap.layout(0, 0, width, height);
int measuredWidth = View.MeasureSpec.makeMeasureSpec(width, View.MeasureSpec.EXACTLY);
int measuredHeight = View.MeasureSpec.makeMeasureSpec(height, View.MeasureSpec.AT_MOST);
viewBitmap.measure(measuredWidth, measuredHeight);
viewBitmap.layout(0, 0, viewBitmap.getMeasuredWidth(), viewBitmap.getMeasuredHeight());
TextView tv = viewBitmap.findViewById(R.id.tv_background);
tv.setText("这是后台生成图片的标题");
final ImageView imageView = viewBitmap.findViewById(R.id.iv_background);
//注意加载网络图片时一定要用SimpleTarget回调
Glide.with(activity).load(url).asBitmap().into(new SimpleTarget() {
@Override
public void onResourceReady(Bitmap resource, GlideAnimation glideAnimation) {
imageView.setImageBitmap(resource);
viewSaveToImage(viewBitmap);
}
});
}/**
* 把view转成图片
* @param view
*/
private void viewSaveToImage(View view) {
view.setDrawingCacheEnabled(true);
view.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_HIGH);
view.setDrawingCacheBackgroundColor(Color.WHITE);
// 把一个View转换成图片
Bitmap cachebmp = viewConversionBitmap(view);
if (mBitmapDoneListener != null){
mBitmapDoneListener.bitmapDone(cachebmp);
}view.destroyDrawingCache();
}
6. 圆角画中画
/**
* view转bitmap
*/
public Bitmap viewConversionBitmap(View v) {
int w = v.getWidth();
int h = v.getHeight();
Bitmap bmp = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(bmp);
c.drawColor(Color.WHITE);
/** 如果不设置canvas画布为白色，则生成透明 */v.layout(0, 0, w, h);
v.draw(c);
return bmp;
}/**
* 把上面获得的bitmap传进来就可以得到圆角的bitmap了
*/
public void bitmapInBitmap(Bitmap bitmap, ImageView imageView) {
Bitmap tempBitmap = bitmap.copy(Bitmap.Config.ARGB_8888, true);
Canvas canvas = new Canvas(tempBitmap);
//图像上画矩形
Paint paint = new Paint();
paint.setColor(Color.TRANSPARENT);
paint.setStyle(Paint.Style.STROKE);
//不填充
paint.setStrokeWidth(10);
//线的宽度
canvas.drawRect(10, 20, 100, 100, paint);
imageView.setImageBitmap(tempBitmap);
//画中画
Paint photoPaint = new Paint();
// 建立画笔
photoPaint.setDither(true);
// 获取跟清晰的图像采样
photoPaint.setFilterBitmap(true);
// 过滤一些Rect src = https://www.it610.com/article/new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
// 创建一个指定的新矩形的坐标
Rect dst = new Rect(0, 0, 300, 350);
// 创建一个指定的新矩形的坐标
canvas.drawBitmap(tempBitmap, src, dst, photoPaint);
// 将photo 缩放或则扩大到
imageView.setImageBitmap(getRoundedCornerBitmap(tempBitmap));
}/**
*生成圆角图片
*/
public Bitmap getRoundedCornerBitmap(Bitmap bitmap) {
try {
Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
bitmap.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, bitmap.getWidth(),
bitmap.getHeight());
final RectF rectF = new RectF(new Rect(0, 0, bitmap.getWidth(),
bitmap.getHeight()));
//设置圆角大小
final float roundPx = 30;
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(Color.BLACK);
canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
final Rect src = new Rect(0, 0, bitmap.getWidth(),
bitmap.getHeight());
canvas.drawBitmap(bitmap, src, rect, paint);
return output;
} catch (Exception e) {
return bitmap;
}
}
以上就是所有的view转bitmap操作，得到bitmap之后你们就可以为所欲为了- -
再次提醒一下：加载网络图片要使用simpleTarget回调，直接加载得到的是一片空白，切记！！！
目前博主只试过glide一种图片框架，其他框架请自行试验，有需要demo的私聊我
第一次写博客，写的不好的地方望指正。
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