英文:
C# - Error where cannot deserialize the current JSON array
问题
我想显示州和城市的列表。
以下是我做的州和城市列表：
```json
[
{ "State": "California",
"City":
["Los Angeles",
"San Diego",
"San Francisco"
]
},
{ "State": "Texas",
"City":
["Houston",
"San Antonio",
"Dallas"
]
}
]
这是我的代码：
List<string> stateCities = new List<string>();
var dictionary = stateCities.Select(x => JsonConvert.DeserializeObject<Dictionary<string, object>>(x))
.ToDictionary(x => x["State"].ToString(), x => ((JArray)x["City"]).ToObject<List<string>>());
lookUpEditState.Properties.DataSource = dictionary;
lookUpEditState.Properties.ValueMember = "State";
lookUpEditCity.Properties.DataSource = dictionary;
lookUpEditCity.Properties.ValueMember = "City";
lookUpEditCity.CascadingOwner = lookUpEditState;
我得到了这个错误：
设置失败：无法将当前的 JSON 数组（例如 [1,2,3]）反序列化为类型 'System.Collections.Generic.Dictionary`2[System.String,System.Object]'，因为该类型需要一个 JSON 对象（例如 {"name":"value"}）才能正确反序列化。
要解决此错误，要么将 JSON 更改为 JSON 对象（例如 {"name":"value"}），要么将反序列化类型更改为数组或实现集合接口的类型（例如 ICollection、IList），如可从 JSON 数组反序列化的 List。
也可以向类型添加 JsonArrayAttribute，强制它从 JSON 数组反序列化。路径 '', 第1行，第1个位置。
有什么办法可以解决这个问题吗？谢谢
<details>
<summary>英文:</summary>
I want to display the list of state and city.
The following is the list for state and city that I've done:
```json
[
{ "State": "California",
"City":
["Los Angeles",
"San Diego",
"San Francisco"
]
},
{ "State": "Texas",
"City":
["Houston",
"San Antonio",
"Dallas"
]
}
]
Here is my code
List<string> stateCities = new List<string>();
var dictionary = stateCities.Select(x => JsonConvert.DeserializeObject<Dictionary<string, object>>(x))
.ToDictionary(x => x["State"].ToString(), x => ((JArray)x["City"]).ToObject<List<string>>());
lookUpEditState.Properties.DataSource = dictionary;
lookUpEditState.Properties.ValueMember = "State";
lookUpEditCity.Properties.DataSource = dictionary;
lookUpEditCity.Properties.ValueMember = "City";
lookUpEditCity.CascadingOwner = lookUpEditState;
}
i got this error:
> Fail to setup: Cannot deserialize the current JSON array (e.g. [1,2,3]) into type
'System.Collections.Generic.Dictionary`2[System.String,System.Object]' because the type requires a JSON object (e.g. {"name":"value"}) to deserialize correctly.
To fix this error either change the JSON to a JSON object (e.g. {"name":"value"}) or change the deserialized type to an array or a type that implements a collection interface (e.g. ICollection, IList) like List<T> that can be deserialized from a JSON array.
JsonArrayAttribute can also be added to the type to force it to deserialize from a JSON array. Path '', line 1, position 1.
Any idea how can i fix this? Thank you
答案1
得分: 2
你需要使用与其表示匹配的类来反序列化JSON。在这种情况下，你有一个具有State和City属性的对象数组，所以你可以这样使用：
var template = new [] { new { State = "", City = new string[] {} }};
var array = JsonConvert.DeserializeAnonymousType(jsonText, template);
如果你真的想要，然后你可以将其转换为字典：
var dictionary = array.ToDictionary(x => x.State, y => y.City);
...这将给你一个 Dictionary<string, string[]>。
英文:
You need to deserialize JSON using a class that matches its representation. In this case you have an array of objects that have a State and City property, so you could use this:
var template = new [] { new { State = "", City = new string[] {} }};
var array = JsonConvert.DeserializeAnonymousType(jsonText, template);
You could then convert it to a dictionary if you really want:
var dictionary = array.ToDictionary( x => x.State, y => y.City );
...which will give you a Dictionary<string,string[]>.
答案2
得分: 1
这对我有效
Dictionary<string, List<string>> dictionary = JArray.Parse(json)
.ToDictionary(ja => (string)ja["State"],ja => ja["City"]
.Select(i => (string)i).ToList());
英文:
This works for me
Dictionary<string, List<string>> dictionary = JArray.Parse(json)
.ToDictionary(ja => (string)ja["State"],ja => ja["City"]
.Select(i => (string)i).ToList());
</details>
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