Question

Im trying to start working with Windows Forms… And I tryed to make programm by lesson… But it doesnt work and I dont understand why. If someone can help me it would be great.

My error:

1>ClCompile:
1>  stdafx.cpp
1>  AssemblyInfo.cpp
1>  Form.cpp
1>Form.cpp(16): error C2872: 'Form1' : ambiguous symbol
1>          could be 'Form1'
1>          or       'c:\users\mizuru\documents\visual studio 2010\projects\form\form\Form1.h(15) : Form1::Form1'
1>Form.cpp(16): error C2061: syntax error : identifier 'Form1'
1>  Generating Code...
1>
1>Build FAILED.

Form.cpp

// Form.cpp : main project file.
    #include "stdafx.h"
    #include "Form1.h"

    using namespace Form1;

    [STAThreadAttribute]
    int main(array<System::String ^> ^args)
    {
        // Enabling Windows XP visual effects before any controls are created
        Application::EnableVisualStyles();
        Application::SetCompatibleTextRenderingDefault(false); 

        // Create the main window and run it
        Application::Run(gcnew Form1());
        return 0;
    }

Form1.h

#pragma once

namespace Form1 {

    using namespace System;
    using namespace System::ComponentModel;
    using namespace System::Collections;
        using namespace System::Windows::Forms;
        using namespace System::Data;
        using namespace System::Drawing;

        /// <summary>
        /// Summary for Form1
        /// </summary>
        public ref class Form1 : public System::Windows::Forms::Form
        {
        public:
            Form1(void)
            {
                InitializeComponent();
                //
                //TODO: Add the constructor code here
                //
            }

        protected:
            /// <summary>
            /// Clean up any resources being used.
            /// </summary>
            ~Form1()
            {
                if (components)
                {
                    delete components;
                }
            }
        private: System::Windows::Forms::Button^  button1;
        protected: 
        private: System::Windows::Forms::Label^  label1;
        private: System::Windows::Forms::TextBox^  textBox1;

        private:
            /// <summary>
            /// Required designer variable.
            /// </summary>
            System::ComponentModel::Container ^components;

    #pragma region Windows Form Designer generated code
            /// <summary>
            /// Required method for Designer support - do not modify
            /// the contents of this method with the code editor.
            /// </summary>
            void InitializeComponent(void)
            {
                this->button1 = (gcnew System::Windows::Forms::Button());
                this->label1 = (gcnew System::Windows::Forms::Label());
                this->textBox1 = (gcnew System::Windows::Forms::TextBox());
                this->SuspendLayout();
                // 
                // button1
                // 
                this->button1->Location = System::Drawing::Point(113, 181);
                this->button1->Name = L"button1";
                this->button1->Size = System::Drawing::Size(75, 23);
                this->button1->TabIndex = 0;
                this->button1->Text = L"button1";
                this->button1->UseVisualStyleBackColor = true;
                this->button1->Click += gcnew System::EventHandler(this, &Form1::button1_Click);
                // 
                // label1
                // 
                this->label1->AutoSize = true;
                this->label1->Location = System::Drawing::Point(104, 13);
                this->label1->Name = L"label1";
                this->label1->Size = System::Drawing::Size(35, 13);
                this->label1->TabIndex = 1;


        this->label1->Text = L"label1";
            // 
            // textBox1
            // 
            this->textBox1->Location = System::Drawing::Point(113, 110);
            this->textBox1->Name = L"textBox1";
            this->textBox1->Size = System::Drawing::Size(100, 20);
            this->textBox1->TabIndex = 2;
            this->textBox1->TextChanged += gcnew System::EventHandler(this, &Form1::textBox1_TextChanged);
            // 
            // Form1
            // 
            this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
            this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
            this->ClientSize = System::Drawing::Size(284, 262);
            this->Controls->Add(this->textBox1);
            this->Controls->Add(this->label1);
            this->Controls->Add(this->button1);
            this->Name = L"Form1";
            this->Text = L"Form1";
            this->ResumeLayout(false);
            this->PerformLayout();

        }
#pragma endregion
    private: System::Void textBox1_TextChanged(System::Object^  sender, System::EventArgs^  e) {
                 label1->Text="";
             }
    private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) {
                 label1->Text=textBox1->Text;
             }
    };
}

Answer 1

The problem at hand is that your namespace and your form class both share the name Form1. You have to disambiguate the symbol by specifying that it’s the class within the namespace.

Application::Run(gcnew ::Form1::Form1());