Application.Run Metoda

Definice

Obor názvů:

System.Windows.Forms

Sestavení:

System.Windows.Forms.dll

Začne v aktuálním vlákně spouštět standardní smyčku zpráv aplikace.

Přetížení

Run()	Spustí standardní smyčku zpráv aplikace v aktuálním vlákně bez formuláře.
Run(ApplicationContext)	Začne spouštět standardní smyčku zpráv aplikace v aktuálním vlákně s .ApplicationContext
Run(Form)	Spustí standardní smyčku zpráv aplikace na aktuálním vlákně a zviditelní zadaný formulář.

Run()

Spustí standardní smyčku zpráv aplikace v aktuálním vlákně bez formuláře.

public:
 static void Run();

public static void Run ();

static member Run : unit -> unit

Public Shared Sub Run ()

Výjimky

InvalidOperationException

V tomto vlákně je již spuštěna hlavní smyčka zpráv.

Poznámky

V aplikaci založené na Win32 nebo model Windows Forms je smyčka zpráv rutinou v kódu, který zpracovává uživatelské události, jako jsou kliknutí myší a tahy klávesnice. Každá spuštěná aplikace pro Windows vyžaduje aktivní smyčku zpráv, která se nazývá hlavní smyčka zpráv. Při zavření hlavní smyčky zpráv se aplikace ukončí. V model Windows Forms je tato smyčka uzavřena při Exit zavolání metody nebo při ExitThread zavolání metody ve vlákně, ve kterém je spuštěna hlavní smyčka zpráv.

Většina vývojářů model Windows Forms nebude muset tuto verzi metody používat. Přetížení byste měli použít Run(Form) ke spuštění aplikace s hlavním formulářem, aby aplikace byla ukončena při zavření hlavního formuláře. Ve všech ostatních situacích použijte Run(ApplicationContext) přetížení, které podporuje dodání objektu ApplicationContext pro lepší kontrolu nad životností aplikace.

Viz také

• Exit()
• ExitThread()
• DoEvents()

Run(ApplicationContext)

Začne spouštět standardní smyčku zpráv aplikace v aktuálním vlákně s .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)

Parametry

context

ApplicationContext

Ve ApplicationContext kterém je aplikace spuštěna.

Výjimky

InvalidOperationException

V tomto vlákně je již spuštěna hlavní smyčka zpráv.

Příklady

Příklad zobrazí dva formuláře a ukončí aplikaci, když jsou oba formuláře zavřené. Při spuštění a ukončení aplikace se zapamatuje pozice každého formuláře. Tento příklad ukazuje, jak použít společně s metodou ApplicationContextApplication.Run(context) k zobrazení více formulářů při spuštění aplikace.

Třída MyApplicationContext dědí z ApplicationContext a sleduje, když je každý formulář zavřen, a opustí aktuální vlákno, když jsou oba. Třída ukládá pozice jednotlivých formulářů pro uživatele. Data umístění formuláře jsou uložena v souboru s názvem Appdata.txt , který je vytvořen v umístění určeném nástrojem UserAppDataPath. Volání Main metody Application.Run(context) ke spuštění aplikace vzhledem k ApplicationContext.

Kód formulářů AppForm1 a AppForm2 se nezobrazuje za účelem zkrácení. Celý výpis kódu najdete v ApplicationContext přehledu třídy.

// 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

Poznámky

Smyčka zpráv běží, dokud Exit není volána nebo ThreadExitExitThread je vyvolána událost kontextového objektu.

Viz také

• Exit()
• ExitThread()
• DoEvents()

Run(Form)

Spustí standardní smyčku zpráv aplikace na aktuálním vlákně a zviditelní zadaný formulář.

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)

Parametry

mainForm

Form

A Form , který představuje formulář, který má být viditelný.

Výjimky

InvalidOperationException

Hlavní smyčka zpráv je již spuštěna v aktuálním vlákně.

Příklady

Následující příklad kódu uvádí čísla v seznamu ve formuláři. Pokaždé, když kliknete na button1, přidá aplikace do seznamu další číslo.

Voláním Main metody Run se spustí aplikace, která vytvoří formulář listBox1, a button1. Když uživatel klikne na button1, button1_Click metoda přidá čísla 1 až tři do seznamu a zobrazí MessageBox. Pokud uživatel klikne na ne na MessageBox, button1_Click metoda přidá do seznamu další číslo. Pokud uživatel klikne na Ano, aplikace zavolá ke Exit zpracování všech zbývajících zpráv ve frontě a k ukončení.

Příklad vyžaduje, aby listBox1 a button1 byly vytvořeny a umístěny ve formuláři.

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

Poznámky

Hlavní funkce aplikace obvykle volá tuto metodu a předá jí hlavní okno aplikace.

Tato metoda přidá obslužnou rutinu události do parametru mainFormClosed pro událost. Obslužná rutina události volá ExitThread k vyčištění aplikace.

Poznámka

Metoda DisposeForm třídy bude volána před vrácením této metody.

Viz také

• Exit()
• ExitThread()
• DoEvents()