如何使用我的类数组的变量 [英] how to use the variable of my class array

问题描述

如果我的代码在这里:

here if my codes:

public:ref class d
		{
		public:
			int i;
		};
#pragma endregion
	private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) {
				 array<d^>^ u = gcnew array<d^>(4);
				 u[1]->i = 9;

			 }

然后运行程序，出现NullReferenceException.我不知道为什么以及如何解决它.
我想使用u [0]，u [1]，u [3]....

then run the program,there comes out a NullReferenceException. I don''t know why and how to fix it.
I want to use u[0],u[1],u[3]....

推荐答案

代码中有一些小错误.它们..您正在创建一个包含4个元素的新数组，但每个元素也需要在使用之前进行初始化...无需将其公开:ref使用public ref代替

Some small misktakes in the code.. I have corrected them.. You are creating a new array with 4 elements but each element also needs to be initialized before using... no need to put public:ref use public ref instead

public ref class d 
	   {
	   public:
		   int i;
	   };

在这里，我为u [1]创建了一个新对象d，然后再使用它.

Here I have crated a new object d for u[1] before using it..

     array<d^> ^u = gcnew array<d^>(4);
u[1] = gcnew d;
u[1]->i = 9;

希望这对您有帮助...

Hope this helps...

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