场景：

logger.Info("f: " + wx.From);

logger.Info("c: " + wx.Code);

logger.Info("s: " + wx.State);

Response.Redirect("https://open.weixin.qq.com/connect/oauth2/authorize?appid=8RAN90uJ1967wpt1Y5&redirect_uri=www.xxxx.com%3a8001%2fWxAuthPage.aspx?from=notreserve&response_type=code&scope=snsapi_base&state=1#wechat_redirect");

出现：

除了code不一致，其它一致。

这样导致如下两次插入：

var mealtake = new MealTake

{

Id = Guid.NewGuid(),

IsTaked = true,

TakeDate = DateTime.Now,

MealType = mt.MealType,

PersonOrder = personOrder

};

context.Set<MealTake>().Add(mealtake);

context.SaveChanges();

 

想到的解决方法：

Response.Redirect("https://open.weixin.qq.com/connect/oauth2/authorize?appid=8RAN90uJ1967wpt1Y5&redirect_uri=www.xxxx.com%3a8001%2fWxAuthPage.aspx?from=notreserve&response_type=code&scope=snsapi_base&state=1#wechat_redirect");

改成

Response.Redirect("https://open.weixin.qq.com/connect/oauth2/authorize?appid=8RAN90uJ1967wpt1Y5&redirect_uri=www.xxxx.com%3a8001%2fWxAuthPage.aspx?from=notreserve&response_type=code&scope=snsapi_base&state="+Guid.NewGuid().ToString()+"#wechat_redirect");

 

再把插入代码改成

if (!context.Set<PersonOrder>().Any(n => n.Comment == wx.State))

{

　　var person = context.Set<MealPerson>().Include("PersonType").FirstOrDefault(n => n.Id == wxUserInfo.User.Id);

　　var personOrder = MealOrderService.CreatePersonOrder(person, mt.MealType, mealdate, false);

　　personOrder.Comment = wx.State;

　　var mealtake = new MealTake

　　{

　　　　Id = Guid.NewGuid(),

　　　　IsTaked = true,

　　　　TakeDate = DateTime.Now,

　　　　MealType = mt.MealType,

　　　　PersonOrder = personOrder

　　};

　　context.Set<MealTake>().Add(mealtake);

　　context.SaveChanges();

}

=============================================================

具体原因，原来是redirect_uri导致的，漏了对redirect_uri进行完整的UrlEncode：

redirect_uri=www.xxxx.com%3a8001%2fWxAuthPage.aspx?from=notreserve

改成

redirect_uri=www.xxxx.com%3a8001%2fWxAuthPage.aspx%3ffrom%3dnotreserve

就不会发生两次回调了