相关疑难解决方法(0)

我想解析"3.5"一个双字符串的字符串.然而,

double.Parse("3.5") 

收益35和

double.Parse("3.5", System.Globalization.NumberStyles.AllowDecimalPoint) 

抛出一个FormatException.

现在我的计算机的语言环境设置为德语,其中逗号用作小数分隔符.它可能需要做些什么并double.Parse()期待"3,5"作为输入,但我不确定.

如何解析包含十进制数的字符串,该十进制数可能是也可能不是我当前语言环境中指定的格式？

我看到这个代码使用LINQ to SQL,但是当我使用Entity Framework时,它会抛出此错误:

LINQ to Entities无法识别方法'System.Linq.IQueryable'1 [MyProject.Models.CommunityFeatures] GetCommunityFeatures()'方法,并且此方法无法转换为商店表达式.

存储库代码是这样的:

public IQueryable<Models.Estate> GetEstates()
{
    return from e in entity.Estates
           let AllCommFeat = GetCommunityFeatures()
           let AllHomeFeat = GetHomeFeatures()
           select new Models.Estate
                      {
                                EstateId = e.EstateId,
                                AllHomeFeatures = new LazyList<HomeFeatures>(AllHomeFeat),
                                AllCommunityFeatures = new LazyList<CommunityFeatures>(AllCommFeat)
                      };
}

public IQueryable<Models.CommunityFeatures> GetCommunityFeatures()
{
    return from f in entity.CommunityFeatures
           select new CommunityFeatures
                      {
                          Name = f.CommunityFeature1,
                          CommunityFeatureId = f.CommunityFeatureId
                      };
}

public IQueryable<Models.HomeFeatures> GetHomeFeatures()
{
    return from f in entity.HomeFeatures
           select new HomeFeatures()
           {
               Name = …

我有以下linq表达式.我想在Nvarchar字段中计算数值的总和.我使用以下代码来执行此操作.但是当我尝试运行它时,我收到一个错误.

var m = new MaterialModelContainer();

var list = 
    (from x in
        (
            from inv in m.INVs
            join l in m.LIBs on inv.MESC equals l.MESC
            join o in m.OUTs on inv.MESC equals o.MESC
            join t in m.TRANs on inv.MESC equals t.MESC
            where t.TYPE == "60"
            select new
            {
                l.MESC,
                l.LINE_NO,
                l.UNIT_LINE,
                Description = l.DES + " " + l.PART_NO,
                inv.NEW_QTY,
                o.PJ,
                o.DATE,
                o.QTY,
                o.QTY_REC,
                TranQty = t.QTY,
                tranDate = t.DATE
            }
        )
        group x by
            new
            {
                x.MESC,
                x.LINE_NO,
                x.UNIT_LINE, …