用兩個級別數組c填充複雜結構＃

Question

我想將值設置爲我的結構編寫的C＃和我得到一個錯誤。

private struct pack2 
    { 
     public float var; 
     public float [3]var2; 
    } 
    private struct pack 
    { 
     public pack2[] ster; 
    } 

private void recv() 
{ 
    pack mystruct; 
    mystruct.ster = new pack2[4]; // Because I need to declare 4 structures of pack2 
    mystruct.ster[0].var = 2F; 
    mystruct.ster[0].var[0] = 1F; // error 
} 

錯誤：NullReferenceException異常是未處理的，ADDINFO：對象引用不設置到對象

我怎麼能解決這個問題的一個實例？

解決：

private struct pack2 
     { 
      public float var; 
      public float [3]var2; 
     } 
     private struct pack 
     { 
      public pack2[] ster; 
     } 

    private void recv() 
    { 
     pack mystruct; 
     mystruct.ster = new pack2[4]; // Because I need to declare 4 structures of pack2 
     mystruct.ster[0].var = 2F; 
     mystruct.ster[0].var2 = new float[3]; // Because I need 3 floats on each pack2 
     mystruct.ster[1].var2 = new float[3]; // Because I need 3 floats on each pack2 
     mystruct.ster[2].var2 = new float[3]; // Because I need 3 floats on each pack2 
     mystruct.ster[3].var2 = new float[3]; // Because I need 3 floats on each pack2 
     mystruct.ster[0].var2[0] = 1F; 
     mystruct.ster[0].var2[1] = 1F; 
     mystruct.ster[0].var2[2] = 1F; 
    } 

我希望這將是有用的人。感謝alex

Answer 1

您需要初始化數組。

// One instance 
ster = new pack2[1]; 

你可以找到更多關於數組here的信息。

結構在實際代碼中很少用到。大多數時候你應該使用課堂。

請參閱此answer何時使用結構（很少）。