【已解决】error C2750: ‘System::Windows::Forms::OpenFileDialog’ : cannot use ‘new’ on the reference type; use ‘gcnew’ instead XXXhelloworld_vcForm1.h 98

【已解决】error C2750: ‘System::Windows::Forms::OpenFileDialog’ : cannot use ‘new’ on the reference type; use ‘gcnew’ instead XXXhelloworld_vcForm1.h 98

【问题背景】

VS2005下，打算在一个button1的click函数中添加一个OpenFileDialog，添加这样的代码：

 OpenFileDialog ofdOpenMp3 = new OpenFileDialog();

结果编译出错：

error C2750: ‘System::Windows::Forms::OpenFileDialog’ : cannot use ‘new’ on the reference type; use ‘gcnew’ instead XXXprojectshelloworld_vchelloworld_vcForm1.h 98

【解决办法】

按照提示，去用gcnew替代new，变成这样：

OpenFileDialog^ ofdOpenMp3 = gcnew OpenFileDialog;

对应的VS2005的help中的解释：

gcnew creates an instance of a managed type (reference or value type) on the garbage collected heap. The result of the evaluation of a gcnew expression is a handle (^) to the type being created.

具体的意思就是，用gcnew在managed heap上新建一个对象，对应的^abc中的abc不是对象，而是相当于对象的指针。

所以后续引用对象中的成员，不用点”.”，而是用箭头“->”，如下：

ofdOpenMp3->Title = “Open a Mp3 File”;

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