Application.Run Método

Definición

Espacio de nombres:

System.Windows.Forms

Ensamblado:

System.Windows.Forms.dll

Inicia la ejecución de un bucle de mensajes de aplicación estándar en el subproceso actual.

Sobrecargas

Run()	Inicia la ejecución de un bucle de mensajes de aplicación estándar en el subproceso actual, sin un formulario.
Run(ApplicationContext)	Inicia la ejecución de un bucle de mensajes de aplicación estándar en el subproceso actual, con un ApplicationContext.
Run(Form)	Inicia la ejecución de un bucle de mensajes de aplicación estándar en el subproceso actual y hace que el formulario especificado esté visible.

Run()

Inicia la ejecución de un bucle de mensajes de aplicación estándar en el subproceso actual, sin un formulario.

public:
 static void Run();

public static void Run ();

static member Run : unit -> unit

Public Shared Sub Run ()

Excepciones

InvalidOperationException

Ya se está ejecutando un bucle de mensajes principal en este subproceso.

Comentarios

En una aplicación basada en Win32 o Windows Forms, un bucle de mensajes es una rutina en el código que procesa eventos de usuario, como clics del mouse y trazos de teclado. Cada aplicación basada en Windows en ejecución requiere un bucle de mensajes activo, denominado bucle de mensajes principal. Cuando se cierra el bucle de mensajes principal, se cierra la aplicación. En Windows Forms, este bucle se cierra cuando se llama al Exit método o cuando se llama al ExitThread método en el subproceso que ejecuta el bucle de mensajes principal.

La mayoría de los desarrolladores Windows Forms no tendrán que usar esta versión del método . Debe usar la Run(Form) sobrecarga para iniciar una aplicación con un formulario principal, de modo que la aplicación finalice cuando se cierre el formulario principal. Para todas las demás situaciones, use la Run(ApplicationContext) sobrecarga , que admite el suministro de un ApplicationContext objeto para un mejor control sobre la duración de la aplicación.

Consulte también

• Exit()
• ExitThread()
• DoEvents()

Run(ApplicationContext)

Inicia la ejecución de un bucle de mensajes de aplicación estándar en el subproceso actual, con un ApplicationContext.

public:
 static void Run(System::Windows::Forms::ApplicationContext ^ context);

public static void Run (System.Windows.Forms.ApplicationContext context);

static member Run : System.Windows.Forms.ApplicationContext -> unit

Public Shared Sub Run (context As ApplicationContext)

Parámetros

context

ApplicationContext

ApplicationContext en el que se ejecuta la aplicación.

Excepciones

InvalidOperationException

Ya se está ejecutando un bucle de mensajes principal en este subproceso.

Ejemplos

En el ejemplo se muestran dos formularios y se cierra la aplicación cuando ambos formularios están cerrados. Cuando se inicia y sale la aplicación, se recuerda la posición de cada formulario. En este ejemplo se muestra cómo usar , ApplicationContextjunto con el Application.Run(context) método , para mostrar varios formularios cuando se inicia la aplicación.

La clase MyApplicationContext hereda de ApplicationContext y realiza un seguimiento cuando se cierra cada formulario y sale del subproceso actual cuando ambos están. La clase almacena las posiciones de cada formulario para el usuario. Los datos de posición del formulario se almacenan en un archivo titulado Appdata.txt que se crea en la ubicación determinada por UserAppDataPath. El Main método llama Application.Run(context) a para iniciar la aplicación según .ApplicationContext

El código de los AppForm1 formularios y AppForm2 no se muestra a efectos de brevedad. Consulte la información general de la clase para obtener toda la ApplicationContext lista de código.

// The class that handles the creation of the application windows
ref class MyApplicationContext: public ApplicationContext
{
private:
   int _formCount;
   AppForm1^ _form1;
   AppForm2^ _form2;
   System::Drawing::Rectangle _form1Position;
   System::Drawing::Rectangle _form2Position;
   FileStream^ _userData;

public:

   MyApplicationContext()
   {
      _formCount = 0;
      
      // Handle the ApplicationExit event to know when the application is exiting.
      Application::ApplicationExit += gcnew EventHandler( this, &MyApplicationContext::OnApplicationExit );
      try
      {
         
         // Create a file that the application will store user specific data in.
         _userData = gcnew FileStream( String::Concat( Application::UserAppDataPath, "\\appdata.txt" ),FileMode::OpenOrCreate );
      }
      catch ( IOException^ e ) 
      {
         
         // Inform the user that an error occurred.
         MessageBox::Show( "An error occurred while attempting to show the application. The error is: {0}", dynamic_cast<String^>(e) );
         
         // Exit the current thread instead of showing the windows.
         ExitThread();
      }

      
      // Create both application forms and handle the Closed event
      // to know when both forms are closed.
      _form1 = gcnew AppForm1;
      _form1->Closed += gcnew EventHandler( this, &MyApplicationContext::OnFormClosed );
      _form1->Closing += gcnew CancelEventHandler( this, &MyApplicationContext::OnFormClosing );
      _formCount++;
      _form2 = gcnew AppForm2;
      _form2->Closed += gcnew EventHandler( this, &MyApplicationContext::OnFormClosed );
      _form2->Closing += gcnew CancelEventHandler( this, &MyApplicationContext::OnFormClosing );
      _formCount++;
      
      // Get the form positions based upon the user specific data.
      if ( ReadFormDataFromFile() )
      {
         
         // If the data was read from the file, set the form
         // positions manually.
         _form1->StartPosition = FormStartPosition::Manual;
         _form2->StartPosition = FormStartPosition::Manual;
         _form1->Bounds = _form1Position;
         _form2->Bounds = _form2Position;
      }

      
      // Show both forms.
      _form1->Show();
      _form2->Show();
   }

   void OnApplicationExit( Object^ /*sender*/, EventArgs^ /*e*/ )
   {
      
      // When the application is exiting, write the application data to the
      // user file and close it.
      WriteFormDataToFile();
      try
      {
         
         // Ignore any errors that might occur while closing the file handle.
         _userData->Close();
      }
      catch ( Exception^ ) 
      {
      }

   }

private:

   void OnFormClosing( Object^ sender, CancelEventArgs^ /*e*/ )
   {
      
      // When a form is closing, remember the form position so it
      // can be saved in the user data file.
      if ( dynamic_cast<AppForm1^>(sender) != nullptr )
            _form1Position = (dynamic_cast<Form^>(sender))->Bounds;
      else
      if ( dynamic_cast<AppForm1^>(sender) != nullptr )
            _form2Position = (dynamic_cast<Form^>(sender))->Bounds;
   }

   void OnFormClosed( Object^ /*sender*/, EventArgs^ /*e*/ )
   {
      
      // When a form is closed, decrement the count of open forms.
      // When the count gets to 0, exit the app by calling
      // ExitThread().
      _formCount--;
      if ( _formCount == 0 )
      {
         ExitThread();
      }
   }

   bool WriteFormDataToFile()
   {
      
      // Write the form positions to the file.
      UTF8Encoding^ encoding = gcnew UTF8Encoding;
      RectangleConverter^ rectConv = gcnew RectangleConverter;
      String^ form1pos = rectConv->ConvertToString( _form1Position );
      String^ form2pos = rectConv->ConvertToString( _form2Position );
      array<Byte>^dataToWrite = encoding->GetBytes( String::Concat( "~", form1pos, "~", form2pos ) );
      try
      {
         
         // Set the write position to the start of the file and write
         _userData->Seek( 0, SeekOrigin::Begin );
         _userData->Write( dataToWrite, 0, dataToWrite->Length );
         _userData->Flush();
         _userData->SetLength( dataToWrite->Length );
         return true;
      }
      catch ( Exception^ ) 
      {
         
         // An error occurred while attempting to write, return false.
         return false;
      }

   }

   bool ReadFormDataFromFile()
   {
      
      // Read the form positions from the file.
      UTF8Encoding^ encoding = gcnew UTF8Encoding;
      String^ data;
      if ( _userData->Length != 0 )
      {
         array<Byte>^dataToRead = gcnew array<Byte>(_userData->Length);
         try
         {
            
            // Set the read position to the start of the file and read.
            _userData->Seek( 0, SeekOrigin::Begin );
            _userData->Read( dataToRead, 0, dataToRead->Length );
         }
         catch ( IOException^ e ) 
         {
            String^ errorInfo = dynamic_cast<String^>(e);
            
            // An error occurred while attempt to read, return false.
            return false;
         }
         
         // Parse out the data to get the window rectangles
         data = encoding->GetString( dataToRead );
         try
         {
            
            // Convert the String* data to rectangles
            RectangleConverter^ rectConv = gcnew RectangleConverter;
            String^ form1pos = data->Substring( 1, data->IndexOf( "~", 1 ) - 1 );
            _form1Position =  *safe_cast<Rectangle^>(rectConv->ConvertFromString( form1pos ));
            String^ form2pos = data->Substring( data->IndexOf( "~", 1 ) + 1 );
            _form2Position =  *safe_cast<Rectangle^>(rectConv->ConvertFromString( form2pos ));
            return true;
         }
         catch ( Exception^ ) 
         {
            
            // Error occurred while attempting to convert the rectangle data.
            // Return false to use default values.
            return false;
         }
      }
      else
      {
         
         // No data in the file, return false to use default values.
         return false;
      }
   }
};

// The class that handles the creation of the application windows
class MyApplicationContext : ApplicationContext
{

    private int _formCount;
    private AppForm1 _form1;
    private AppForm2 _form2;

    private Rectangle _form1Position;
    private Rectangle _form2Position;

    private FileStream _userData;

    private MyApplicationContext()
    {
        _formCount = 0;

        // Handle the ApplicationExit event to know when the application is exiting.
        Application.ApplicationExit += new EventHandler(this.OnApplicationExit);

        try
        {
            // Create a file that the application will store user specific data in.
            _userData = new FileStream(Application.UserAppDataPath + "\\appdata.txt", FileMode.OpenOrCreate);
        }
        catch (IOException e)
        {
            // Inform the user that an error occurred.
            MessageBox.Show("An error occurred while attempting to show the application." +
                            "The error is:" + e.ToString());

            // Exit the current thread instead of showing the windows.
            ExitThread();
        }

        // Create both application forms and handle the Closed event
        // to know when both forms are closed.
        _form1 = new AppForm1();
        _form1.Closed += new EventHandler(OnFormClosed);
        _form1.Closing += new CancelEventHandler(OnFormClosing);
        _formCount++;

        _form2 = new AppForm2();
        _form2.Closed += new EventHandler(OnFormClosed);
        _form2.Closing += new CancelEventHandler(OnFormClosing);
        _formCount++;

        // Get the form positions based upon the user specific data.
        if (ReadFormDataFromFile())
        {
            // If the data was read from the file, set the form
            // positions manually.
            _form1.StartPosition = FormStartPosition.Manual;
            _form2.StartPosition = FormStartPosition.Manual;

            _form1.Bounds = _form1Position;
            _form2.Bounds = _form2Position;
        }

        // Show both forms.
        _form1.Show();
        _form2.Show();
    }

    private void OnApplicationExit(object sender, EventArgs e)
    {
        // When the application is exiting, write the application data to the
        // user file and close it.
        WriteFormDataToFile();

        try
        {
            // Ignore any errors that might occur while closing the file handle.
            _userData.Close();
        }
        catch { }
    }

    private void OnFormClosing(object sender, CancelEventArgs e)
    {
        // When a form is closing, remember the form position so it
        // can be saved in the user data file.
        if (sender is AppForm1)
            _form1Position = ((Form)sender).Bounds;
        else if (sender is AppForm2)
            _form2Position = ((Form)sender).Bounds;
    }

    private void OnFormClosed(object sender, EventArgs e)
    {
        // When a form is closed, decrement the count of open forms.

        // When the count gets to 0, exit the app by calling
        // ExitThread().
        _formCount--;
        if (_formCount == 0)
        {
            ExitThread();
        }
    }

    private bool WriteFormDataToFile()
    {
        // Write the form positions to the file.
        UTF8Encoding encoding = new UTF8Encoding();

        RectangleConverter rectConv = new RectangleConverter();
        string form1pos = rectConv.ConvertToString(_form1Position);
        string form2pos = rectConv.ConvertToString(_form2Position);

        byte[] dataToWrite = encoding.GetBytes("~" + form1pos + "~" + form2pos);

        try
        {
            // Set the write position to the start of the file and write
            _userData.Seek(0, SeekOrigin.Begin);
            _userData.Write(dataToWrite, 0, dataToWrite.Length);
            _userData.Flush();

            _userData.SetLength(dataToWrite.Length);
            return true;
        }
        catch
        {
            // An error occurred while attempting to write, return false.
            return false;
        }
    }

    private bool ReadFormDataFromFile()
    {
        // Read the form positions from the file.
        UTF8Encoding encoding = new UTF8Encoding();
        string data;

        if (_userData.Length != 0)
        {
            byte[] dataToRead = new byte[_userData.Length];

            try
            {
                // Set the read position to the start of the file and read.
                _userData.Seek(0, SeekOrigin.Begin);
                _userData.Read(dataToRead, 0, dataToRead.Length);
            }
            catch (IOException e)
            {
                string errorInfo = e.ToString();
                // An error occurred while attempt to read, return false.
                return false;
            }

            // Parse out the data to get the window rectangles
            data = encoding.GetString(dataToRead);

            try
            {
                // Convert the string data to rectangles
                RectangleConverter rectConv = new RectangleConverter();
                string form1pos = data.Substring(1, data.IndexOf("~", 1) - 1);

                _form1Position = (Rectangle)rectConv.ConvertFromString(form1pos);

                string form2pos = data.Substring(data.IndexOf("~", 1) + 1);
                _form2Position = (Rectangle)rectConv.ConvertFromString(form2pos);

                return true;
            }
            catch
            {
                // Error occurred while attempting to convert the rectangle data.
                // Return false to use default values.
                return false;
            }
        }
        else
        {
            // No data in the file, return false to use default values.
            return false;
        }
    }

    [STAThread]
    static void Main(string[] args)
    {

        // Create the MyApplicationContext, that derives from ApplicationContext,
        // that manages when the application should exit.

        MyApplicationContext context = new MyApplicationContext();

        // Run the application with the specific context. It will exit when
        // all forms are closed.
        Application.Run(context);
    }
}

' The class that handles the creation of the application windows
Public Class MyApplicationContext
    Inherits ApplicationContext

    Private _formCount As Integer
    Private _form1 As AppForm1
    Private _form2 As AppForm2

    Private _form1Position As Rectangle
    Private _form2Position As Rectangle

    Private _userData As FileStream

    Public Sub New()
        MyBase.New()
        _formCount = 0

        ' Handle the ApplicationExit event to know when the application is exiting.
        AddHandler Application.ApplicationExit, AddressOf OnApplicationExit

        Try
            ' Create a file that the application will store user specific data in.
            _userData = New FileStream(Application.UserAppDataPath + "\appdata.txt", FileMode.OpenOrCreate)

        Catch e As IOException
            ' Inform the user that an error occurred.
            MessageBox.Show("An error occurred while attempting to show the application." +
                            "The error is:" + e.ToString())

            ' Exit the current thread instead of showing the windows.
            ExitThread()
        End Try

        ' Create both application forms and handle the Closed event
        ' to know when both forms are closed.
        _form1 = New AppForm1()
        AddHandler _form1.Closed, AddressOf OnFormClosed
        AddHandler _form1.Closing, AddressOf OnFormClosing
        _formCount = _formCount + 1

        _form2 = New AppForm2()
        AddHandler _form2.Closed, AddressOf OnFormClosed
        AddHandler _form2.Closing, AddressOf OnFormClosing
        _formCount = _formCount + 1

        ' Get the form positions based upon the user specific data.
        If (ReadFormDataFromFile()) Then
            ' If the data was read from the file, set the form
            ' positions manually.
            _form1.StartPosition = FormStartPosition.Manual
            _form2.StartPosition = FormStartPosition.Manual

            _form1.Bounds = _form1Position
            _form2.Bounds = _form2Position
        End If

        ' Show both forms.
        _form1.Show()
        _form2.Show()
    End Sub

    Private Sub OnApplicationExit(ByVal sender As Object, ByVal e As EventArgs)
        ' When the application is exiting, write the application data to the
        ' user file and close it.
        WriteFormDataToFile()

        Try
            ' Ignore any errors that might occur while closing the file handle.
            _userData.Close()
        Catch
        End Try
    End Sub

    Private Sub OnFormClosing(ByVal sender As Object, ByVal e As CancelEventArgs)
        ' When a form is closing, remember the form position so it
        ' can be saved in the user data file.
        If TypeOf sender Is AppForm1 Then
            _form1Position = CType(sender, Form).Bounds
        ElseIf TypeOf sender Is AppForm2 Then
            _form2Position = CType(sender, Form).Bounds
        End If
    End Sub

    Private Sub OnFormClosed(ByVal sender As Object, ByVal e As EventArgs)
        ' When a form is closed, decrement the count of open forms.

        ' When the count gets to 0, exit the app by calling
        ' ExitThread().
        _formCount = _formCount - 1
        If (_formCount = 0) Then
            ExitThread()
        End If
    End Sub

    Private Function WriteFormDataToFile() As Boolean
        ' Write the form positions to the file.
        Dim encoding As UTF8Encoding = New UTF8Encoding()

        Dim rectConv As RectangleConverter = New RectangleConverter()
        Dim form1pos As String = rectConv.ConvertToString(_form1Position)
        Dim form2pos As String = rectConv.ConvertToString(_form2Position)

        Dim dataToWrite As Byte() = encoding.GetBytes("~" + form1pos + "~" + form2pos)

        Try
            ' Set the write position to the start of the file and write
            _userData.Seek(0, SeekOrigin.Begin)
            _userData.Write(dataToWrite, 0, dataToWrite.Length)
            _userData.Flush()

            _userData.SetLength(dataToWrite.Length)
            Return True

        Catch
            ' An error occurred while attempting to write, return false.
            Return False
        End Try

    End Function

    Private Function ReadFormDataFromFile() As Boolean
        ' Read the form positions from the file.
        Dim encoding As UTF8Encoding = New UTF8Encoding()
        Dim data As String

        If (_userData.Length <> 0) Then
            Dim dataToRead(_userData.Length) As Byte

            Try
                ' Set the read position to the start of the file and read.
                _userData.Seek(0, SeekOrigin.Begin)
                _userData.Read(dataToRead, 0, dataToRead.Length)

            Catch e As IOException
                Dim errorInfo As String = e.ToString()
                ' An error occurred while attempt to read, return false.
                Return False
            End Try

            ' Parse out the data to get the window rectangles
            data = encoding.GetString(dataToRead)

            Try
                ' Convert the string data to rectangles
                Dim rectConv As RectangleConverter = New RectangleConverter()
                Dim form1pos As String = data.Substring(1, data.IndexOf("~", 1) - 1)

                _form1Position = CType(rectConv.ConvertFromString(form1pos), Rectangle)

                Dim form2pos As String = data.Substring(data.IndexOf("~", 1) + 1)
                _form2Position = CType(rectConv.ConvertFromString(form2pos), Rectangle)

                Return True

            Catch
                ' Error occurred while attempting to convert the rectangle data.
                ' Return false to use default values.
                Return False
            End Try

        Else
            ' No data in the file, return false to use default values.
            Return False
        End If
    End Function

End Class

Public Module MyApplication
    Public Sub Main()
        ' Create the MyApplicationContext, that derives from ApplicationContext,
        ' that manages when the application should exit.

        Dim context As MyApplicationContext = New MyApplicationContext()

        ' Run the application with the specific context. It will exit when
        ' all forms are closed.
        Application.Run(context)
    End Sub
End Module

Comentarios

El bucle de mensajes se ejecuta hasta Exit que se llama a o ExitThread se genera el ThreadExit evento en el objeto de contexto.

Consulte también

• Exit()
• ExitThread()
• DoEvents()

Run(Form)

Inicia la ejecución de un bucle de mensajes de aplicación estándar en el subproceso actual y hace que el formulario especificado esté visible.

public:
 static void Run(System::Windows::Forms::Form ^ mainForm);

public static void Run (System.Windows.Forms.Form mainForm);

static member Run : System.Windows.Forms.Form -> unit

Public Shared Sub Run (mainForm As Form)

Parámetros

mainForm

Form

Form que representa el formulario que va a estar visible.

Excepciones

InvalidOperationException

Un bucle de mensajes principal ya se está ejecutando en el subproceso actual.

Ejemplos

En el ejemplo de código siguiente se enumeran los números de un cuadro de lista de un formulario. Cada vez que haga clic en button1, la aplicación agrega otro número a la lista.

El Main método llama Run a para iniciar la aplicación, que crea el formulario, listBox1y button1. Cuando el usuario hace clic en button1, el button1_Click método agrega los números uno a tres al cuadro de lista y muestra .MessageBox Si el usuario hace clic en No en MessageBox, el button1_Click método agrega otro número a la lista. Si el usuario hace clic en Sí, la aplicación llama Exit a para procesar todos los mensajes restantes de la cola y, a continuación, para salir.

El ejemplo requiere que listBox1 y button1 se hayan creado y colocado en un formulario.

public:
   static void main()
   {
      // Starts the application.
      Application::Run( gcnew Form1 );
   }

private:
   void button1_Click( Object^ sender, System::EventArgs^ e )
   {
      // Populates a list box with three numbers.
      int i = 3;
      for ( int j = 1; j <= i; j++ )
      {
         listBox1->Items->Add( j );
      }
      
      /* Determines whether the user wants to exit the application.
       * If not, adds another number to the list box. */
      while ( MessageBox::Show( "Exit application?", "",
         MessageBoxButtons::YesNo ) == ::DialogResult::No )
      {
         // Increments the counter ands add the number to the list box.
         i++;
         listBox1->Items->Add( i );
      }
      
      // The user wants to exit the application. Close everything down.
      Application::Exit();
   }

public static void Main(string[] args) {
    // Starts the application.
    Application.Run(new Form1());
 }

 private void button1_Click(object sender, System.EventArgs e) {
    // Populates a list box with three numbers.
    int i = 3;
    for(int j=1; j<=i; j++) {
       listBox1.Items.Add(j);
    }

    /* Determines whether the user wants to exit the application.
     * If not, adds another number to the list box. */
    while (MessageBox.Show("Exit application?", "", MessageBoxButtons.YesNo) ==
       DialogResult.No) {
       // Increments the counter ands add the number to the list box.
       i++;
       listBox1.Items.Add(i);
    }

    // The user wants to exit the application. Close everything down.
    Application.Exit();
 }

<STAThread()> _
Shared Sub Main() 	
   ' Starts the application.
   Application.Run(New Form1())
End Sub

Private Sub button1_Click(sender As object, e As System.EventArgs)
   ' Populates a list box with three numbers.
   Dim i As Integer = 3
   Dim j As Integer
   For j = 1 To i - 1
      listBox1.Items.Add(j)
   Next

   ' Checks to see whether the user wants to exit the application.
   ' If not, adds another number to the list box.
   While (MessageBox.Show("Exit application?", "", MessageBoxButtons.YesNo) = _ 
      DialogResult.No)
      ' Increments the counter and adds the number to the list box.
      i = i + 1
      listBox1.Items.Add(i)
   End While

   ' The user wants to exit the application. Close everything down.
   Application.Exit()
End Sub

Comentarios

Normalmente, la función principal de una aplicación llama a este método y la pasa a la ventana principal de la aplicación.

Este método agrega un controlador de eventos al mainForm parámetro para el Closed evento. El controlador de eventos llama ExitThread a para limpiar la aplicación.

Nota

Se Dispose llamará al método de la Form clase antes de la devolución de este método.

Consulte también

• Exit()
• ExitThread()
• DoEvents()