微信开发：(Android)在线图片无法分享，发送按钮无法点击

最近在做微信分享功能，可是无法分享在线图片，点击分享后，跳转到微信发状态界面，但是“发送按钮”不可点击，并且无预览图。分享本地图片可以正常分享。问题如图：

代码如下：

new Thread() {
                @Override
                public void run() {
                    try{
                        WXImageObject imgObj = new WXImageObject();
                        imgObj.imageUrl = imgUrl;//右侧是预先定义的图片链接

                        WXMediaMessage msg = new WXMediaMessage();
                        msg.mediaObject = imgObj;

                        Bitmap bmp = BitmapFactory.decodeStream(new URL(imgUrl).openStream());
                        Bitmap thumbBmp = Bitmap.createScaledBitmap(bmp, THUMB_SIZE, THUMB_SIZE, true);//THUMB_SIZE = 150;
                        bmp.recycle();//bitmap回收
                        msg.thumbData = Util.bmpToByteArray(thumbBmp, true);//将bitmap转为byte数组后回收bitmap

                        SendMessageToWX.Req req = new SendMessageToWX.Req();
                        req.transaction = buildTransaction("img");//通过"img"生成唯一标志
                        req.message = msg;
                        req.scene = SendMessageToWX.Req.WXSceneTimeline;
                        api.sendReq(req);

                    } catch(Exception e) {
                        e.printStackTrace();
                    }
                };

            }.start();

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