Question

我正在尝试在C＃中反序列化JSON但是我得到NullReferenceException并且我不知道为什么。

这是我要解析的JSON：

{"Entries": {"Entry": {"day": "28","month": "10","year": "1955","type": "birthday","title": "Bill Gates was born!","picture": "","video": ""}}}

我正在使用此代码

public class Entry
{
    public string day { get; set; }
    public string month { get; set; }
    public string year { get; set; }
    public string type { get; set; }
    public string title { get; set; }
    public string picture { get; set; }
    public string video { get; set; }
}

public class Entries
{
    public List<Entry> entry { get; set; }
}

private void buttonSearch_Click(object sender, EventArgs e)
{
    string json = new StreamReader("events.json").ReadToEnd();
    var entries = JsonConvert.DeserializeObject<Entries>(json);
    MessageBox.Show(entries.entry[0].day); // NullReferenceException
}

为什么我会收到此错误以及如何解决？

当我将JSON更改为

时

{"Entries": ["Entry": {"day": "28","month": "10","year": "1955","type": "birthday","title": "Bill Gates was born!","picture": "","video": ""}]}

我得到After parsing a value an unexpected character was encountered: :. Path 'Entries[0]', line 1, position 20.

修改

我和JSON一起玩，而另一个人对我有用：

[{"day": "28","month": "10","year": "1955","type": "birthday","title": "Bill Gates was born!","picture": "","video": ""}]

Answer 1

你的json是正确的，如果你应该按如下方式更改类定义，那么这将有效

（顺便说一句：你可能会发现this site很有用）

var entries = JsonConvert.DeserializeObject<Root>(json);

public class Entry
{
    public string day { get; set; }
    public string month { get; set; }
    public string year { get; set; }
    public string type { get; set; }
    public string title { get; set; }
    public string picture { get; set; }
    public string video { get; set; }
}

public class Entries
{
    public Entry Entry { get; set; }
}

public class Root
{
    public Entries Entries { get; set; }
}

在C＃中反序列化JSON

1 个答案: