https://developers.weixin.qq.com/doc/oplatform/Mobile_App/Access_Guide/Android.html

String path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/test.png";
File file = new File(path);

WXImageObject imgObj = new WXImageObject();
imgObj.setImagePath(path);

WXMediaMessage msg = new WXMediaMessage();
msg.mediaObject = imgObj;
msg.title="abc-title";
msg.description="dhsajkdhkashdkahskda";
Bitmap bmp = BitmapFactory.decodeFile(path);
Bitmap thumbBmp = Bitmap.createScaledBitmap(bmp, 200, 200, true);
bmp.recycle();
msg.thumbData = bmpToByteArray(thumbBmp, true);

SendMessageToWX.Req req = new SendMessageToWX.Req();
req.transaction = "img"+System.currentTimeMillis();
req.message = msg;
req.scene = SendMessageToWX.Req.WXSceneTimeline ;
IWXAPI api = WXAPIFactory.createWXAPI(WebViewActivity.this, "app-key");

api.sendReq(req);

设置了标题和描述，但实际没有效果，默认文字一直为空