MyForm2：未声明的标识符

Question

我已经为这个错误苦苦挣扎了一段时间。

我正在尝试实现 ATM 系统的登录，并且我正在尝试将其连接到数据库。但是当我尝试运行它时，显示了 144 个完全相同的错误：

'MyForm2': is not a member of 'jiji'

'MyForm2': undeclared identifier

Syntax error: missing ';' before identifier 'f2'

'f2':undeclared identifier

老实说，我不知道为什么会这样。我试图在主代码中包含 MyForm2.h 但没有任何变化。

在这里，我留下了我所有 7 种形式几乎相同的一段代码（除了第二个，我认为这是给出错误的那个）

MyForm.h:

    private: System::Void button1_Click(System::Object^ sender, System::EventArgs^ e) {
    
        try {
            String^ User = textBox1->Text;
            String^ Pwd = textBox2->Text;
            int AN = Int32::Parse(textBox3->Text);

            String^ constr = "Server=127.0.0.1;Uid=root;Pwd=;Database=visualcppdb";
            MySqlConnection^ con = gcnew MySqlConnection(constr);

            MySqlDataAdapter^ da = gcnew MySqlDataAdapter("Select AccountNum from Userinfo WHERE AccountNum = '" + AN + "'", con);
            DataTable^ dt = gcnew DataTable();
            da->Fill(dt);

            if (dt->Rows->Count >= 1) {
                MySqlCommand^ cmd = gcnew MySqlCommand("insert into Db values (" + AN + ") ", con);

                con->Open();
                MySqlDataReader^ dr = cmd->ExecuteReader();
                con->Close();

                try {
                    this->Hide();
                    jiji::MyForm2 f2;
                    f2.ShowDialog();
                    this->Show();
                }
                finally {
                    this->Close();
                }
            }
            else {
                MessageBox::Show("User does not exist, try again");
            }
        }
        catch (Exception^ e) {
            MessageBox::Show(e->Message);
        }
    }

顺便说一句，AN 是帐号。

MyForm2.h代码一遍又一遍地相同，除了结尾。

MyForm2.h:

//Extract money 
    private: System::Void button1_Click(System::Object^ sender, System::EventArgs^ e) {
    
        try {
            this->Hide();
            jiji::MyForm3 f3;
            f3.ShowDialog();
            this->Show();
        }
        finally {
            this->Close();
        }
    }
    
           //Insert Money
    private: System::Void button2_Click(System::Object^ sender, System::EventArgs^ e) {
    
        try {
            this->Hide();
            jiji::MyForm4 f4;
            f4.ShowDialog();
            this->Show();
        }
        finally {
            this->Close();
        }
    }
    
           //Transfer
    private: System::Void button3_Click(System::Object^ sender, System::EventArgs^ e) {
    
        try {
            this->Hide();
            jiji::MyForm5 f5;
            f5.ShowDialog();
            this->Show();
        }
        finally {
            this->Close();
        }
    }
    
           //Check Amount
    private: System::Void button4_Click(System::Object^ sender, System::EventArgs^ e) {
    
        try {
            this->Hide();
            jiji::MyForm6 f6;
            f6.ShowDialog();
            this->Show();
        }
        finally {
            this->Close();
        }
    }
    
           //Reload phone
    private: System::Void button5_Click(System::Object^ sender, System::EventArgs^ e) {
    
        try {
            this->Hide();
            jiji::MyForm7 f7;
            f7.ShowDialog();
            this->Show();
        }
        finally {
            this->Close();
        }
    }

           //Exit
    private: System::Void button6_Click(System::Object^ sender, System::EventArgs^ e) {
        try {
            String^ constr = "Server=127.0.0.1;Uid=root;Pwd=;Database=visualcppdb";
            MySqlConnection^ con = gcnew MySqlConnection(constr);

            MySqlCommand^ cmd = gcnew MySqlCommand("TRUNCATE Db ", con);

            con->Open();
            MySqlDataReader^ dr = cmd->ExecuteReader();
            con->Close();

        }
        catch (Exception^ e) {
            MessageBox::Show(e->Message);
        }
        finally {
            this->Close();
        }
    }

Answer 1

也许您没有将 MyForm2.h 包含在 MyForm.h 可以访问的上下文中？

也许研究一下如何声明命名空间以及如何包含 headers，例如Creating a C++ namespace in header and source (cpp)

如果将 MyForm2 class 定义内联到 MyForm 中以保证其可访问，会发生什么情况？

MyForm2：未声明的标识符

MyForm2: undeclared identifier

c++-cli

winforms