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Übersetzung
Englisch

Control::MouseWheel-Ereignis

 

Veröffentlicht: Oktober 2016

Wird ausgelöst, wenn das Mausrad gedreht wird, während das Steuerelement fokussiert ist.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

public:
[BrowsableAttribute(false)]
event MouseEventHandler^ MouseWheel {
	void add(MouseEventHandler^ value);
	void remove(MouseEventHandler^ value);
}

Bei der Behandlung der MouseWheel Ereignis, es wichtig ist, die das Mausrad zugeordneten Benutzer Benutzeroberfläche (UI)-Standards entsprechen. Die MouseEventArgs::Delta Eigenschaftswert angibt, dem Mausrad verschoben wurde. Die Benutzeroberfläche sollte Bildlauf, wenn das Delta plus oder minus 120 ist. Der Benutzeroberfläche die Anzahl der logischen von zurückgegebenen Zeilen ein Bildlauf der SystemInformation::MouseWheelScrollLines -Eigenschaft für jeden Deltawert erreicht. Sie können auch einen Bildlauf reibungslos kleinere, 120 Einheit erhöht jedoch das Verhältnis, d. h. gleich bleibt, sollten SystemInformation::MouseWheelScrollLines Zeilen pro 120 Delta Einheiten Bewegung bewegt.

Weitere Informationen zur Behandlung von Maus Wheel Nachrichten finden Sie unter derWM_MOUSEWHEELThema.

Mausereignisse treten in der folgenden Reihenfolge auf:

  1. MouseEnter

  2. MouseMove

  3. MouseHover / MouseDown / MouseWheel

  4. MouseUp

  5. MouseLeave

Weitere Informationen zur Behandlung von Ereignissen finden Sie unter behandeln und Auslösen von Ereignissen.

Das folgende Codebeispiel veranschaulicht die Verwendung von verschiedenen Mausereignissen gezeichnet der Maus auf ein Panel. Ein Liniensegment hinzugefügt wird die GraphicsPath für jede MouseMove und MouseDown Ereignisse. Zum Aktualisieren der Grafik die Invalidate Methode wird aufgerufen, für die Panel auf jedem MouseDown und MouseUp Ereignis. Darüber hinaus im Grafikpfad wird durch einen Bildlauf nach oben oder unten, wenn die MouseWheel Ereignis auftritt. Zusätzliche Mausereignisse, z. B. MouseHover, werden auf dem Bildschirm auch identifiziert. Auch auf dem Bildschirm angezeigt werden zusätzliche Informationen über die Maus aus der SystemInformation Klasse.

#using <System.dll>
#using <System.Windows.Forms.dll>
#using <System.Drawing.dll>

using namespace System;
using namespace System::Drawing;
using namespace System::Windows::Forms;

namespace MouseEvent
{
   public ref class Form1: public System::Windows::Forms::Form
   {
   private:
      System::Windows::Forms::Panel^ panel1;
      System::Windows::Forms::Label ^ label1;
      System::Windows::Forms::Label ^ label2;
      System::Windows::Forms::Label ^ label3;
      System::Windows::Forms::Label ^ label4;
      System::Windows::Forms::Label ^ label5;
      System::Windows::Forms::Label ^ label6;
      System::Windows::Forms::Label ^ label7;
      System::Windows::Forms::Label ^ label8;
      System::Windows::Forms::Label ^ label9;
      System::Windows::Forms::Button^ clearButton;
      System::Drawing::Drawing2D::GraphicsPath^ mousePath;
      System::Windows::Forms::GroupBox^ groupBox1;
      int fontSize;

   public:
      Form1()
      {
         fontSize = 20;
         mousePath = gcnew System::Drawing::Drawing2D::GraphicsPath;
         this->panel1 = gcnew System::Windows::Forms::Panel;
         this->label1 = gcnew System::Windows::Forms::Label;
         this->clearButton = gcnew System::Windows::Forms::Button;
         this->label2 = gcnew System::Windows::Forms::Label;
         this->label3 = gcnew System::Windows::Forms::Label;
         this->label4 = gcnew System::Windows::Forms::Label;
         this->label5 = gcnew System::Windows::Forms::Label;
         this->label6 = gcnew System::Windows::Forms::Label;
         this->label7 = gcnew System::Windows::Forms::Label;
         this->label8 = gcnew System::Windows::Forms::Label;
         this->label9 = gcnew System::Windows::Forms::Label;
         this->groupBox1 = gcnew System::Windows::Forms::GroupBox;

         // Mouse Events Label
         this->label1->Location = System::Drawing::Point( 24, 504 );
         this->label1->Size = System::Drawing::Size( 392, 23 );

         // DoubleClickSize Label
         this->label2->AutoSize = true;
         this->label2->Location = System::Drawing::Point( 24, 48 );
         this->label2->Size = System::Drawing::Size( 35, 13 );

         // DoubleClickTime Label
         this->label3->AutoSize = true;
         this->label3->Location = System::Drawing::Point( 24, 72 );
         this->label3->Size = System::Drawing::Size( 35, 13 );

         // MousePresent Label
         this->label4->AutoSize = true;
         this->label4->Location = System::Drawing::Point( 24, 96 );
         this->label4->Size = System::Drawing::Size( 35, 13 );

         // MouseButtons Label
         this->label5->AutoSize = true;
         this->label5->Location = System::Drawing::Point( 24, 120 );
         this->label5->Size = System::Drawing::Size( 35, 13 );

         // MouseButtonsSwapped Label
         this->label6->AutoSize = true;
         this->label6->Location = System::Drawing::Point( 320, 48 );
         this->label6->Size = System::Drawing::Size( 35, 13 );

         // MouseWheelPresent Label
         this->label7->AutoSize = true;
         this->label7->Location = System::Drawing::Point( 320, 72 );
         this->label7->Size = System::Drawing::Size( 35, 13 );

         // MouseWheelScrollLines Label
         this->label8->AutoSize = true;
         this->label8->Location = System::Drawing::Point( 320, 96 );
         this->label8->Size = System::Drawing::Size( 35, 13 );

         // NativeMouseWheelSupport Label
         this->label9->AutoSize = true;
         this->label9->Location = System::Drawing::Point( 320, 120 );
         this->label9->Size = System::Drawing::Size( 35, 13 );

         // Mouse Panel
         this->panel1->Anchor = static_cast<System::Windows::Forms::AnchorStyles>(System::Windows::Forms::AnchorStyles::Top | System::Windows::Forms::AnchorStyles::Left | System::Windows::Forms::AnchorStyles::Right);
         this->panel1->BackColor = System::Drawing::SystemColors::ControlDark;
         this->panel1->Location = System::Drawing::Point( 16, 160 );
         this->panel1->Size = System::Drawing::Size( 664, 320 );
         this->panel1->MouseUp += gcnew System::Windows::Forms::MouseEventHandler( this, &Form1::panel1_MouseUp );
         this->panel1->Paint += gcnew System::Windows::Forms::PaintEventHandler( this, &Form1::panel1_Paint );
         this->panel1->MouseEnter += gcnew System::EventHandler( this, &Form1::panel1_MouseEnter );
         this->panel1->MouseHover += gcnew System::EventHandler( this, &Form1::panel1_MouseHover );
         this->panel1->MouseMove += gcnew System::Windows::Forms::MouseEventHandler( this, &Form1::panel1_MouseMove );
         this->panel1->MouseLeave += gcnew System::EventHandler( this, &Form1::panel1_MouseLeave );
         this->panel1->MouseDown += gcnew System::Windows::Forms::MouseEventHandler( this, &Form1::panel1_MouseDown );
         this->panel1->MouseWheel += gcnew System::Windows::Forms::MouseEventHandler( this, &Form1::panel1_MouseWheel );

         // Clear Button
         this->clearButton->Anchor = static_cast<System::Windows::Forms::AnchorStyles>(System::Windows::Forms::AnchorStyles::Top | System::Windows::Forms::AnchorStyles::Right);
         this->clearButton->Location = System::Drawing::Point( 592, 504 );
         this->clearButton->TabIndex = 1;
         this->clearButton->Text = "Clear";
         this->clearButton->Click += gcnew System::EventHandler( this, &Form1::clearButton_Click );

         // GroupBox
         this->groupBox1->Anchor = static_cast<System::Windows::Forms::AnchorStyles>(System::Windows::Forms::AnchorStyles::Top | System::Windows::Forms::AnchorStyles::Left | System::Windows::Forms::AnchorStyles::Right);
         this->groupBox1->Location = System::Drawing::Point( 16, 24 );
         this->groupBox1->Size = System::Drawing::Size( 664, 128 );
         this->groupBox1->Text = "System::Windows::Forms::SystemInformation";

         // Set up how the form should be displayed and add the controls to the form.
         this->ClientSize = System::Drawing::Size( 696, 534 );
         array<System::Windows::Forms::Control^>^temp0 = {this->label9,this->label8,this->label7,this->label6,this->label5,this->label4,this->label3,this->label2,this->clearButton,this->panel1,this->label1,this->groupBox1};
         this->Controls->AddRange( temp0 );
         this->Text = "Mouse Event Example";

         // Displays information about the system mouse.
         label2->Text = "SystemInformation::DoubleClickSize: {0}",SystemInformation::DoubleClickSize;
         label3->Text = "SystemInformation::DoubleClickTime: {0}",SystemInformation::DoubleClickTime;
         label4->Text = "SystemInformation::MousePresent: {0}",SystemInformation::MousePresent;
         label5->Text = "SystemInformation::MouseButtons: {0}",SystemInformation::MouseButtons;
         label6->Text = "SystemInformation::MouseButtonsSwapped: {0}",SystemInformation::MouseButtonsSwapped;
         label7->Text = "SystemInformation::MouseWheelPresent: {0}",SystemInformation::MouseWheelPresent;
         label8->Text = "SystemInformation::MouseWheelScrollLines: {0}",SystemInformation::MouseWheelScrollLines;
         label9->Text = "SystemInformation::NativeMouseWheelSupport: {0}",SystemInformation::NativeMouseWheelSupport;
      }

   private:
      void panel1_MouseDown( Object^ /*sender*/, System::Windows::Forms::MouseEventArgs^ e )
      {
         // Update the mouse path with the mouse information
         Point mouseDownLocation = Point(e->X,e->Y);
         String^ eventString = nullptr;
         switch ( e->Button )
         {
            case ::MouseButtons::Left:
               eventString = "L";
               break;

            case ::MouseButtons::Right:
               eventString = "R";
               break;

            case ::MouseButtons::Middle:
               eventString = "M";
               break;

            case ::MouseButtons::XButton1:
               eventString = "X1";
               break;

            case ::MouseButtons::XButton2:
               eventString = "X2";
               break;

            case ::MouseButtons::None:
            default:
               break;
         }
         if ( eventString != nullptr )
         {
            mousePath->AddString( eventString, FontFamily::GenericSerif, (int)FontStyle::Bold, (float)fontSize, mouseDownLocation, StringFormat::GenericDefault );
         }
         else
         {
            mousePath->AddLine( mouseDownLocation, mouseDownLocation );
         }

         panel1->Focus();
         panel1->Invalidate();
      }

      void panel1_MouseEnter( Object^ sender, System::EventArgs^ /*e*/ )
      {

         // Update the mouse event label to indicate the MouseEnter event occurred.
         label1->Text = String::Concat( sender->GetType(), ": MouseEnter" );
      }

      void panel1_MouseHover( Object^ sender, System::EventArgs^ /*e*/ )
      {

         // Update the mouse event label to indicate the MouseHover event occurred.
         label1->Text = String::Concat( sender->GetType(), ": MouseHover" );
      }

      void panel1_MouseLeave( Object^ sender, System::EventArgs^ /*e*/ )
      {

         // Update the mouse event label to indicate the MouseLeave event occurred.
         label1->Text = String::Concat( sender->GetType(), ": MouseLeave" );
      }

      void panel1_MouseMove( Object^ /*sender*/, System::Windows::Forms::MouseEventArgs^ e )
      {
         // Update the mouse path that is drawn onto the Panel.
         int mouseX = e->X;
         int mouseY = e->Y;
         mousePath->AddLine( mouseX, mouseY, mouseX, mouseY );
      }

      void panel1_MouseWheel( Object^ /*sender*/, System::Windows::Forms::MouseEventArgs^ e )
      {
         // Update the drawing based upon the mouse wheel scrolling.
         int numberOfTextLinesToMove = e->Delta * SystemInformation::MouseWheelScrollLines / 120;
         int numberOfPixelsToMove = numberOfTextLinesToMove * fontSize;
         if ( numberOfPixelsToMove != 0 )
         {
            System::Drawing::Drawing2D::Matrix^ translateMatrix = gcnew System::Drawing::Drawing2D::Matrix;
            translateMatrix->Translate( 0, (float)numberOfPixelsToMove );
            mousePath->Transform(translateMatrix);
         }

         panel1->Invalidate();
      }

      void panel1_MouseUp( Object^ /*sender*/, System::Windows::Forms::MouseEventArgs^ e )
      {
         Point mouseUpLocation = System::Drawing::Point( e->X, e->Y );

         // Show the number of clicks in the path graphic.
         int numberOfClicks = e->Clicks;
         mousePath->AddString( String::Format( "   {0}", numberOfClicks ), FontFamily::GenericSerif, (int)FontStyle::Bold, (float)fontSize, mouseUpLocation, StringFormat::GenericDefault );
         panel1->Invalidate();
      }

      void panel1_Paint( Object^ /*sender*/, System::Windows::Forms::PaintEventArgs^ e )
      {
         // Perform the painting of the Panel.
         e->Graphics->DrawPath( System::Drawing::Pens::DarkRed, mousePath );
      }

      void clearButton_Click( Object^ /*sender*/, System::EventArgs^ /*e*/ )
      {
         // Clear the Panel display.
         delete mousePath;
         mousePath = gcnew System::Drawing::Drawing2D::GraphicsPath;
         panel1->Invalidate();
      }
   };
}

[STAThread]
int main()
{
   Application::Run( gcnew MouseEvent::Form1 );
}

.NET Framework
Verfügbar seit 1.1
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