WebView截图

初始化webview之前，不然截图只有当前显示的部分，其余为空白

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
    android.webkit.WebView.enableSlowWholeDocumentDraw();
}

截图调用

private Bitmap captureWebViewLollipop() {
        float scale = mWebView.getScale();
        int width = mWebView.getWidth();
        int height = (int) (mWebView.getContentHeight() * scale + 0.5);
        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);
        Canvas canvas = new Canvas(bitmap);
        mWebView.draw(canvas);
        return bitmap;
    }