C# 字典<>；。ContainesKey给出RuntimeBinderException

在.cshtml中，我想检查

目录

中是否存在一个键，但我总是得到一个错误，并且找不到原因

这是我的代码：

@foreach (KeyValuePair<int, int> weekAndYear in @ViewBag.WeekAndYears)
{
    int key = int.Parse(weekAndYear.Value + "" + weekAndYear.Key);

    bool exist = ViewBag.Menus.ContainsKey(key);
}

@foreach（KeyValuePair weekAndYear in@ViewBag.WeekAndYears）
{
int key=int.Parse（weekAndYear.Value+“”+weekAndYear.key）；
bool exist=ViewBag.Menus.ContainsKey（键）；
}

我得到的错误是：

The best overloaded method match for System.Collections.Generic.Dictionary<int,Object>.this[int] has some invalid arguments

System.Collections.Generic.Dictionary的最佳重载方法匹配。此[int]具有一些无效参数

当我只使用.Key或.Value时，它仍然有效

编辑-解决方案

---

问题是什么，我不知道，但我已经用以下代码解决了问题：

foreach (KeyValuePair<int, int> weekAndYear in @ViewBag.WeekAndYears)
    {
        int key = int.Parse(weekAndYear.Value + "" + weekAndYear.Key);

        bool exist = ((Dictionary<int, Object>)ViewBag.Menus).ContainsKey(key);
}

foreach (KeyValuePair<int, int> weekAndYear in @ViewBag.WeekAndYears)
    {
        int key = int.Parse(weekAndYear.Value + "" + weekAndYear.Key);

        bool exist = ((Dictionary<int, Object>)ViewBag.Menus).ContainsKey(key);
}

foreach（KeyValuePair weekAndYear in@ViewBag.WeekAndYears）
{
int key=int.Parse（weekAndYear.Value+“”+weekAndYear.key）；
boolexist=（（字典）ViewBag.Menus）.ContainsKey（键）；
}

您是否可以尝试使用TryGetValue而不是ContainsKey，看看它是否有效：

@foreach (KeyValuePair<int, int> weekAndYear in @ViewBag.WeekAndYears)
{
    int key = int.Parse(weekAndYear.Value + "" + weekAndYear.Key); 
    Object outValue;
    bool exist = Menus.TryGetValue(key, out outValue);
}

@foreach（KeyValuePair weekAndYear in@ViewBag.WeekAndYears）
{
int key=int.Parse（weekAndYear.Value+“”+weekAndYear.key）；
客体价值；
bool exist=Menus.TryGetValue（键，输出值）；
}

问题是什么，我不知道，但我已经用以下代码解决了问题：

foreach (KeyValuePair<int, int> weekAndYear in @ViewBag.WeekAndYears)
    {
        int key = int.Parse(weekAndYear.Value + "" + weekAndYear.Key);

        bool exist = ((Dictionary<int, Object>)ViewBag.Menus).ContainsKey(key);
}

foreach (KeyValuePair<int, int> weekAndYear in @ViewBag.WeekAndYears)
    {
        int key = int.Parse(weekAndYear.Value + "" + weekAndYear.Key);

        bool exist = ((Dictionary<int, Object>)ViewBag.Menus).ContainsKey(key);
}

foreach（KeyValuePair weekAndYear in@ViewBag.WeekAndYears）
{
int key=int.Parse（weekAndYear.Value+“”+weekAndYear.key）；
boolexist=（（字典）ViewBag.Menus）.ContainsKey（键）；
}

您从何处获得此错误以及

@ViewBag.week和years

？在@foreach循环中，您的KeyValuePair应该是KeyValuePair而不是KeyValuePair。这可能就是问题所在。

@ViewBag.week和years

是

字典

。我在

ContainsKey（键）

上得到错误

@ViewBag.menu

是

字典

当查找失败时，键的值是多少？@InContext即使失败，

键的值也是
int
@ViewBag.WeekAndYears
包含
{31:2014，32:2014，33:2014}
不错，这也行！我使用了另一个解决方案，并将其放置在问题区域，因为我无法回答自己的问题。