從JSON文件中讀取，寫入和追加

Question

我一直試圖正確解析一段時間的json文件，但似乎無法正確解析。我已經嘗試了很多教程和json.net庫，但是似乎無法找到正確的方法來解決這個問題。我的文件都具有相同的格式：

file.json：

{ 
    "Expense": { 
    "Name": "something", 
    "Amount": "34.90", 
    "Due": "28/12/2011", 
    "Recurrence": "1 Months", 
    "Paid": "0", 
    "LastPaid": "01/01/2002" 
    } 
} 
{ 
    "Expense": { 
    "Name": "OneTel Mobile Bill", 
    "Amount": "39.90", 
    "Due": "28/12/2011", 
    "Recurrence": "1 Months", 
    "Paid": "0", 
    "LastPaid": "01/01/2002" 
    } 
} 
{ 
    "Expense": { 
    "Name": "some other Bill", 
    "Amount": "44.90", 
    "Due": "28/12/2011", 
    "Recurrence": "1 Months", 
    "Paid": "0", 
    "LastPaid": "01/01/2002" 
    } 
} 

現在，我這裏有兩個問題。但首先，我知道如何編寫json文件。所以這對我來說不是問題。但我的兩個問題是：

如何念想JSON字符串/文件： （僞代碼）

FOREACH VAR EXPENSE IN EXPENSES 
OUTPUT EXPENSE.NAME 
OUTPUT EXPENSE.AMOUNT 

等等...

我的第二個問題是：

如何將一個全新的「費用」添加到現有的json文件中？

我真的很感激你對此的幫助。

謝謝

我寫的JSON的文件，像這樣：

//Create the Json file and save it with WriteToFile(); 
    JObject jobject = 
     new JObject(
      new JProperty("Expense", 
       new JObject(
        new JProperty("Name", NameTextBox.Text), 
        new JProperty("Amount", AmountTextBox.Text), 
        new JProperty("Due", DueTextBox.Text), 
        new JProperty("Recurrence", EveryTextBox.Text + " " + EveryComboBox.SelectionBoxItem), 
        new JProperty("Paid", "0"), 
        new JProperty("LastPaid", "Never") 
          ) 
         ) 
        );    

    try 
    { 
     WriteToFile(Expenses, jobject.ToString()); 

     // Close the flyout now. 
     this.Visibility = Windows.UI.Xaml.Visibility.Collapsed; 

    } 
    catch (Exception exception) 
    { 
     Debug.Write(exception.Message); 

    } 

Answer 1

我認爲你將有一個更容易的時間，如果你創建了一個消費類，然後序列化和讀取集合的費用對象（即List<Expense>）。

public class Expense 
{ 
    public string Name { get; set; } 
    public decimal Amount { get; set; } 
    public DateTime Due { get; set; } 
    public string Recurrence { get; set; } 
    public decimal Paid { get; set; } 
    public DateTime LastPaid{ get; set; } 
} 

public class ExpenseCollection : System.Collections.Generic.List<Expense> 
{ 

} 

然後，您可以使用內置的JavaScriptSerializer類。

粗糙的代碼來創建JSON：

 ExpenseCollection cExpenses = new ExpenseCollection(); 
     // ToDo: Fill the expenses collection 
     var sJSON = (new System.Web.Script.Serialization.JavaScriptSerializer).Serialize(cExpenses); 
     // ToDo: Write sJSON to a file 

，並讀取它（注意，這可能需要一些調整）：

 string sJSON; 
     // ToDo: Read the json from a file 
     ExpenseCollection cExpenses = (new System.Web.Script.Serialization.JavaScriptSerializer).Deserialize<ExpenseCollection>(sJSON); 
     // ToDo: Write sJSON to a file 

Answer 2

我相信你的JSON格式不正確，用連載方法@Competent_tech提到它會產生類似的結果：

"Expense": [ 
    { 
    "Name": "something", 
    "Amount": "34.90", 
    "Due": "28/12/2011", 
    "Recurrence": "1 Months", 
    "Paid": "0", 
    "LastPaid": "01/01/2002" 
} 
{ 
    "Name": "OneTel Mobile Bill", 
    "Amount": "39.90", 
    "Due": "28/12/2011", 
    "Recurrence": "1 Months", 
    "Paid": "0", 
    "LastPaid": "01/01/2002" 
} 
{ 
    "Name": "some other Bill", 
    "Amount": "44.90", 
    "Due": "28/12/2011", 
    "Recurrence": "1 Months", 
    "Paid": "0", 
    "LastPaid": "01/01/2002" 
    } 
]