The old project in the past can’t run today. Wechat payment reported this error. I went to wechat development platform to check it:
the modification is as follows:

exception: register app failed for wechat app signature check failed

At the time of payment:

IWXAPI wxapi = WXAPIFactory.createWXAPI (this,WXAPPID,true);
replace with

IWXAPI wxapi = WXAPIFactory.createWXAPI (mContext,null);