这是Winform1：
#include "Winform2.h"
#include "Winform3.h"
namespace Winform1 {
/// <summary>
/// Summary for Winform1
///
/// WARNING: If you change the name of this class, you will need to change the
/// 'Resource File Name' property for the managed resource compiler tool
/// associated with all .resx files this class depends on. Otherwise,
/// the designers will not be able to interact properly with localized
/// resources associated with this form.
/// </summary>
public ref class Winform1: public System::Windows::Forms::Form
{
public:
private: System::Windows::Forms::Button^ button1;
private: System::Windows::Forms::Button^ button2;
private: System::Windows::Forms::Label^ label1;
private: System::Windows::Forms::Label^ label3;
private: System::Windows::Forms::Button^ button3;
private: System::Windows::Forms::Label^ label2;
private: System::Windows::Forms::Label^ label4;
private: System::Windows::Forms::Button^ button4;
public:
unordered_map<int, std::string>* fb_contas_email;
Usuario* usuario;
WinForm1(Usuario* user,
unordered_map<int, std::string>* fb_contas_)
{
this->fb_contas_email = fb_contas_;
this->usuario = user;
InitializeComponent();
//
//TODO: Add the constructor code here
//
}
private: System::Void button1_Click(System::Object^ sender, System::EventArgs^ e) {
this->Visible = false;
this->Close();
WinForm2 wf2(this->usuario);
wf2.ShowDialog();
}
private: System::Void button2_Click(System::Object^ sender, System::EventArgs^ e) {
this->Visible = false;
this->Close();
WinForm3 wf3(this->usuario);
wf3.ShowDialog();
}
//...
这是Winform2：
#include "Winform1.h"
namespace Winform2 {
/// <summary>
/// Summary for Winform2
///
/// WARNING: If you change the name of this class, you will need to change the
/// 'Resource File Name' property for the managed resource compiler tool
/// associated with all .resx files this class depends on. Otherwise,
/// the designers will not be able to interact properly with localized
/// resources associated with this form.
/// </summary>
public ref class Winform2: public System::Windows::Forms::Form
{
public:
private: System::Windows::Forms::Button^ button1;
private: System::Windows::Forms::Button^ button2;
private: System::Windows::Forms::Label^ label1;
private: System::Windows::Forms::Label^ label3;
private: System::Windows::Forms::Button^ button3;
private: System::Windows::Forms::Label^ label2;
private: System::Windows::Forms::Label^ label4;
private: System::Windows::Forms::Button^ button4;
public:
unordered_map<int, std::string>* fb_contas_email;
Usuario* usuario;
WinForm2(Usuario* user,
unordered_map<int, std::string>* fb_contas_)
{
this->fb_contas_email = fb_contas_;
this->usuario = user;
InitializeComponent();
//
//TODO: Add the constructor code here
//
}
private: System::Void button4_Click(System::Object^ sender, System::EventArgs^ e) {
this->Visible = false;
this->Close();
WinForm1 wf1(this->usuario);
wf1.ShowDialog();
}
//...
这是Winforms 3：
namespace Winform3 {
/// <summary>
/// Summary for Winform3
///
/// WARNING: If you change the name of this class, you will need to change the
/// 'Resource File Name' property for the managed resource compiler tool
/// associated with all .resx files this class depends on. Otherwise,
/// the designers will not be able to interact properly with localized
/// resources associated with this form.
/// </summary>
public ref class Winform3: public System::Windows::Forms::Form
{
public:
private: System::Windows::Forms::Button^ button1;
private: System::Windows::Forms::Button^ button2;
private: System::Windows::Forms::Label^ label1;
private: System::Windows::Forms::Label^ label3;
private: System::Windows::Forms::Button^ button3;
private: System::Windows::Forms::Label^ label2;
private: System::Windows::Forms::Label^ label4;
private: System::Windows::Forms::Button^ button4;
public:
unordered_map<int, std::string>* fb_contas_email;
Usuario* usuario;
WinForm3(Usuario* user,
unordered_map<int, std::string>* fb_contas_)
{
this->fb_contas_email = fb_contas_;
this->usuario = user;
InitializeComponent();
//
//TODO: Add the constructor code here
//
}
//...
如何解决此错误？我需要从Winform1到Winform2来回，反之亦然。但是这会在显示对话框时抛出未定义类的错误，可能是因为我在其中包含了自己的内容。但我需要包含才能再次调用Dialog回来。
我该怎么办？我需要在winform1和winform2之间来回显示一个对话框
提前致谢
答案 0 :(得分：1)
这些代码是代码（.cpp）文件还是头文件？
在我看来，您需要对头文件和代码文件进行C ++样式分离。获取代码，并将其分别只在头文件中，只在.cpp文件中的类实现中分类，并且此编译器错误将消失。
以下是我的想法：你已经宣布了Winform 1,2和3在同一个文件中实现。当两个类都需要相互引用时，这会导致问题。看看这个代码示例，其中两个类互相引用：
Class1.h：
#pragma once
#include "Class2.h"
public ref class Class1
{
public:
void Foo() { Class2^ two = gcnew Class2(); two->Bar() }
void Baz() { }
}
Class2.h：
#pragma once
#include "Class1.h"
public ref class Class2
{
public:
void Bar() { Class1^ one = gcnew Class1(); one->Baz() }
}
现在，当这两个文件被编译时会发生这种情况？ Class1.h将尝试包含Class2.h。 Class2.h将尝试包含Class1.h，但由于#pragma once，它不会。 （我假设您在头文件中有或者#ifdef保护。）当它尝试编译时，它会看到Class2的定义，然后是Class1的定义。当它编译CLass2时，尚未定义Class1，因此您将收到编译器错误。
这里的解决方案是将每个类分成单独的头文件和代码文件。见固定示例：
Class1.h：
#pragma once
public ref class Class1
{
public:
void Foo();
void Baz();
}
Class1.cpp：
#include "Class1.h"
#include "Class2.h"
void Class1::Foo() { Class2^ two = gcnew Class2(); two->Bar() }
void Class1::Baz() { }
Class2.h：
#pragma once
public ref class Class2
{
public:
void Bar();
}
Class2.cpp：
#include "Class2.h"
#include "Class1.h"
void Class2::Bar() { Class1^ one = gcnew Class1(); one->Baz() }