Android WebView实现截长图功能

<WebView 
 android:id="@+id/web_view" 
 android:layout_width="match_parent" 
 android:layout_height="match_parent"/> 

//1:打开缓存开关 
view.setDrawingCacheEnabled(true); 
//2:获取缓存 
Bitmap drawingCache = view.getDrawingCache(); 
//3:拷贝图片(这里就是我们需要的截图内容啦) 
Bitmap newBitmap = Bitmap.createBitmap(drawingCache); 
//4:关闭缓存开关 
view.setDrawingCacheEnabled(false); 

//这些都是View的方法 
webView.setScrollY(); 
webView.scrollTo(); 
webView.scrollBy(); 

//1:发起测量 
mWebView.measure(0, 0); 
//2:获取测量后高度 == Webview的高度 
int contentHeight = mWebView.getMeasuredHeight(); 
//3:获取Webview控件的高度 
int height = mWebView.getHeight(); 
//4:计算滚动次数 
int totalScrollCount = contentHeight / height; 
//5: 剩余高度 
int surplusScrollHeight = contentHeight - (totalScrollCount * height); 
 
//存储图片容器 
List<Bitmap> cacheBitmaps = new ArrayList<>(); 
for (int i = 0; i < totalScrollCount; i++) { 
 if (i > 0) { 
  //滚动WebView 
  mWebView.setScrollY(i * height); 
 } 
 //获取截图,通过步骤1获取,这里不贴代码了 
 Bitmap bitmap = getScreenshot(mWebView); 
 cacheBitmaps.add(bitmap); 
} 
 
//如果不能整除,需要额外滚动1次 
if (surplusScrollHeight > 0) { 
 mWebView.setScrollY(contentHeight); 
 Bitmap bitmap = getScreenshot(mWebView); 
 cacheBitmaps.add(bitmap); 
} 

public Bitmap mergeBitmap(List<Bitmap> datas) { 
 //图纸宽度(因为是截图,图片宽度大小都是一样的) 
 int bitmapWidth = datas.get(0).getWidth(); 
 //图纸高度 = WebView内容的高度 
 int bitmapHeight = contentHeight; 
 //1:创建图纸 
 Bitmap bimap = Bitmap.createBitmap(bitmapWidth, bitmapHeight, Bitmap.Config.RGB_565); 
 //2:创建画布,并绑定图纸 
 Canvas canvas = new Canvas(bimap); 
 //3:创建画笔 
 Paint paint = new Paint(); 
 for (int count = datas.size(), i = 0; i < count; i++) { 
  Bitmap data = datas.get(i); 
  float left = 0; 
  float top = i * data.getHeight(); 
  Rect src = null; 
  RectF des = null; 
  /** 
  * Rect src = new Rect(); 代表图片矩形范围 
  * RectF des = new RectF(); 代表Canvas的矩形范围(显示位置) 
  */ 
  if (i == count - 1 && surplusScrollHeight > 0) { 
  int srcRectTop = data.getHeight() - surplusScrollHeight; 
  src = new Rect(0, srcRectTop, data.getWidth(), data.getHeight()); 
  des = new RectF(left, top, data.getWidth(), top + surplusScrollHeight); 
  } else { 
  src = new Rect(0, 0, data.getWidth(), data.getHeight()); 
  des = new RectF(left, top, data.getWidth(), top + data.getHeight()); 
  } 
  //绘制图片 
  canvas.drawBitmap(data, src, des, paint); 
 } 
 return bimap; 
}