2017-08-21 27 views
2

我創建了一個類對象崩潰說它是NULL

public partial class Subrank 
{ 
    private System.DateTime startDateField; 

    public System.DateTime StartDate 
    { 
     get 
     { 
      return this.startDateField; 
     } 
     set 
     { 
      this.startDateField = value; 
     } 
    } 
} 

IM則試圖建立一個這樣的陣列...

Subrank[] pastSubRank = new Subrank[1]; 
pastSubRank[0].StartDate = DateTime.Parse("2012-05-22"); 

pastSubRank[0]崩潰說它是NULL。 ...爲什麼是這樣?

回答

6

是的,因爲您在訪問它的屬性之前沒有實例化類Subrank

Subrank[] pastSubRank = new Subrank[1]; 
pastSubRank[0] = new Subrank(); 
pastSubRank[0].StartDate = DateTime.Parse("2012-05-22"); 
+0

感謝您的幫助 – John

+0

你也可以寫「Enumerable.Repeat(新Subrank(),1之前創建的目的是把數組).ToArray()'初始化一個對象數組。 –

+0

@John,然後考慮接受答案。 – Rahul

4

您需要訪問屬性

 Subrank[] pastSubRank = new Subrank[1]; 
     pastSubRank[0] = new Subrank(); 
     pastSubRank[0].StartDate = DateTime.Parse("2012-05-22"); 
2
Subrank[] pastSubRank = new Subrank[] 
{ 
    new Subrank() { StartDate = DateTime.Parse("2012-05-22") } 
};