我試圖從json文件中提取數據,但是當我點擊一個按鈕時,它會給出NullReference的異常,實際上在json文件中有一個數據,但它仍然會發出異常。從JSon文件中提取數據的空參考
//Json File Starts With Name myfile
[
{"Name" : "Stack" , "Surname" : "OverFlow"},
{"Name" : "Google", "Surname" : "INc"}
]
// JSON文件結束
[DataContract]
class dt {
public dt(){}
public string Name { get; set; }
public string Surname { get; set; }
}
private async void Button_Click(object sender, RoutedEventArgs e)
{
StorageFile sf = await Windows.ApplicationModel.Package.Current.InstalledLocation.GetFileAsync(@"Assets\myfile.txt");
var dataString = await FileIO.ReadTextAsync(sf);
DataContractJsonSerializer json = new DataContractJsonSerializer(typeof(List<dt>));
MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(dataString));
List<dt> myData = (List<dt>)json.ReadObject(ms);
foreach (var dt in myData)
{
Windows.UI.Popups.MessageDialog md = new Windows.UI.Popups.MessageDialog(dt.Name.ToString() +" "+ dt.Surname.ToString());
await md.ShowAsync();
}
}
隨着你讀它是隻刪除從頂部//註釋那麼有用的文件成爲json有效的字符串。 – AliK