Application.Run Metodo
Definizione
Importante
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Avvia l'esecuzione di un ciclo di messaggi dell'applicazione standard sul thread corrente.
Overload
| Run() |
Avvia l'esecuzione di un ciclo di messaggi dell'applicazione standard sul thread corrente senza un form. |
| Run(ApplicationContext) |
Avvia l'esecuzione di un ciclo di messaggi dell'applicazione standard sul thread corrente con un oggetto ApplicationContext. |
| Run(Form) |
Avvia l'esecuzione di un ciclo di messaggi dell'applicazione standard sul thread corrente e rende visibile il form specificato. |
Run()
Avvia l'esecuzione di un ciclo di messaggi dell'applicazione standard sul thread corrente senza un form.
public:
static void Run();public static void Run ();static member Run : unit -> unitPublic Shared Sub Run ()Eccezioni
Un ciclo di messaggi principale è già in esecuzione su questo thread.
Commenti
In un'applicazione basata su Win32 o Windows Forms, un ciclo di messaggi è una routine nel codice che elabora gli eventi utente, ad esempio i clic del mouse e i tratti da tastiera. Ogni applicazione basata su Windows richiede un ciclo di messaggi attivo, denominato ciclo di messaggi principale. Quando il ciclo di messaggi principale viene chiuso, l'applicazione viene chiusa. In Windows Forms questo ciclo viene chiuso quando viene chiamato il metodo o quando viene chiamato il Exit metodo nel thread che esegue il ExitThread ciclo di messaggi principale.
La maggior parte degli sviluppatori Windows Forms non dovrà usare questa versione del metodo. È consigliabile usare l'overload Run(Form) per avviare un'applicazione con un modulo principale, in modo che l'applicazione venga terminata quando il modulo principale viene chiuso. Per tutte le altre situazioni, usare l'overload Run(ApplicationContext) , che supporta la fornitura di un ApplicationContext oggetto per un migliore controllo sulla durata dell'applicazione.
Vedi anche
Si applica a
Run(ApplicationContext)
Avvia l'esecuzione di un ciclo di messaggi dell'applicazione standard sul thread corrente con un oggetto 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 -> unitPublic Shared Sub Run (context As ApplicationContext)Parametri
- context
- ApplicationContext
Oggetto ApplicationContext nel quale l'applicazione viene eseguita.
Eccezioni
Un ciclo di messaggi principale è già in esecuzione su questo thread.
Esempio
L'esempio visualizza due moduli e chiude l'applicazione quando entrambi i moduli vengono chiusi. All'avvio e all'uscita dell'applicazione, viene ricordata la posizione di ogni modulo. In questo esempio viene illustrato come usare un ApplicationContextoggetto , insieme al Application.Run(context) metodo, per visualizzare più moduli all'avvio dell'applicazione.
La classe MyApplicationContext eredita da ApplicationContext e mantiene traccia quando ogni modulo viene chiuso e chiude il thread corrente quando entrambi sono. La classe archivia le posizioni di ogni modulo per l'utente. I dati di posizione del modulo vengono archiviati in un file denominato Appdata.txt creato nella posizione determinata da UserAppDataPath. Il Main metodo chiama Application.Run(context) per avviare l'applicazione in base a ApplicationContext.
Il codice per i AppForm1 moduli e AppForm2 non viene visualizzato allo scopo di brevità. Vedere la panoramica della classe per l'intero ApplicationContext elenco di codice.
// 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
Commenti
Il ciclo del messaggio viene eseguito fino a Exit quando o ExitThread viene chiamato o l'evento viene generato nell'oggetto ThreadExit contesto.
Vedi anche
Si applica a
Run(Form)
Avvia l'esecuzione di un ciclo di messaggi dell'applicazione standard sul thread corrente e rende visibile il form specificato.
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 -> unitPublic Shared Sub Run (mainForm As Form)Parametri
Eccezioni
Un ciclo di messaggi principale è già in esecuzione sul thread corrente.
Esempio
L'esempio di codice seguente elenca i numeri in una casella di riepilogo in un modulo. Ogni volta che si fa clic su button1, l'applicazione aggiunge un altro numero all'elenco.
Il Main metodo chiama Run per avviare l'applicazione, che crea il modulo, listBox1e button1. Quando l'utente fa clic su button1, il button1_Click metodo aggiunge numeri uno a tre alla casella di riepilogo e visualizza un MessageBoxoggetto . Se l'utente fa clic su No sul MessageBoxmetodo , il button1_Click metodo aggiunge un altro numero all'elenco. Se l'utente fa clic su Sì, l'applicazione chiama Exit per elaborare tutti i messaggi rimanenti nella coda e quindi uscire.
L'esempio richiede che listBox1 sia stato creato e button1 inserito in un modulo.
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
Commenti
In genere, la funzione principale di un'applicazione chiama questo metodo e passa alla finestra principale dell'applicazione.
Questo metodo aggiunge un gestore eventi al mainForm parametro per l'evento Closed . Il gestore eventi chiama ExitThread per pulire l'applicazione.
Vedi anche
Si applica a
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