MeasureItemEventArgs Class
Provides data for the MeasureItem event of the ListBox, ComboBox, CheckedListBox, and MenuItem controls.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
The MeasureItemEventArgs type exposes the following members.
| Name | Description | |
|---|---|---|
![]() | MeasureItemEventArgs(Graphics, Int32) | Initializes a new instance of the MeasureItemEventArgs class. |
![]() | MeasureItemEventArgs(Graphics, Int32, Int32) | Initializes a new instance of the MeasureItemEventArgs class providing a parameter for the item height. |
| Name | Description | |
|---|---|---|
![]() | Equals(Object) | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) |
![]() | Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) |
![]() | GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) |
![]() | GetType | Gets the Type of the current instance. (Inherited from Object.) |
![]() | MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
![]() | ToString | Returns a string that represents the current object. (Inherited from Object.) |
This event is sent when the OwnerDraw property of ListBox, ComboBox, CheckedListBox, or MenuItem is set to true. It is used to tell the drawing function how to size an item.
For information about the event model, see Events and Delegates.
The following code example demonstrates how to use the Graphics property to perform custom drawing of the items in a ListBox.
public ref class Form1: public System::Windows::Forms::Form { private: System::Windows::Forms::ListBox^ listBox1; System::ComponentModel::Container^ components; public: ~Form1() { if ( components != nullptr ) { delete components; } } private: /// <summary> /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// </summary> void InitializeComponent() { this->listBox1 = gcnew System::Windows::Forms::ListBox; this->SuspendLayout(); // // listBox1 // this->listBox1->DrawMode = System::Windows::Forms::DrawMode::OwnerDrawVariable; this->listBox1->Location = System::Drawing::Point( 16, 48 ); this->listBox1->Name = "listBox1"; this->listBox1->SelectionMode = System::Windows::Forms::SelectionMode::MultiExtended; this->listBox1->Size = System::Drawing::Size( 256, 134 ); this->listBox1->TabIndex = 0; this->listBox1->MeasureItem += gcnew System::Windows::Forms::MeasureItemEventHandler( this, &Form1::listBox1_MeasureItem ); this->listBox1->DrawItem += gcnew System::Windows::Forms::DrawItemEventHandler( this, &Form1::listBox1_DrawItem ); // // Form1 // this->ClientSize = System::Drawing::Size( 292, 273 ); array<System::Windows::Forms::Control^>^temp0 = {this->listBox1}; this->Controls->AddRange( temp0 ); this->Name = "Form1"; this->Text = "Form1"; this->ResumeLayout( false ); } void listBox1_MeasureItem( Object^ /*sender*/, MeasureItemEventArgs^ e ) { System::Drawing::Font^ font = (dynamic_cast<ListBoxFontItem^>(listBox1->Items[ e->Index ]))->Font; SizeF stringSize = e->Graphics->MeasureString( font->Name, font ); // Set the height and width of the item e->ItemHeight = (int)stringSize.Height; e->ItemWidth = (int)stringSize.Width; } // For efficiency, cache the brush to use for drawing. SolidBrush^ foreColorBrush; void listBox1_DrawItem( Object^ /*sender*/, DrawItemEventArgs^ e ) { Brush^ brush; // Create the brush using the ForeColor specified by the DrawItemEventArgs if ( foreColorBrush == nullptr ) foreColorBrush = gcnew SolidBrush( e->ForeColor ); else if ( foreColorBrush->Color != e->ForeColor ) { // The control's ForeColor has changed, so dispose of the cached brush and // create a new one. delete foreColorBrush; foreColorBrush = gcnew SolidBrush( e->ForeColor ); } // Select the appropriate brush depending on if the item is selected. // Since State can be a combinateion (bit-flag) of enum values, you can't use // "==" to compare them. if ( (e->State & DrawItemState::Selected) == DrawItemState::Selected ) brush = SystemBrushes::HighlightText; else brush = foreColorBrush; // Perform the painting. System::Drawing::Font^ font = (dynamic_cast<ListBoxFontItem^>(listBox1->Items[ e->Index ]))->Font; e->DrawBackground(); e->Graphics->DrawString( font->Name, font, brush, e->Bounds ); e->DrawFocusRectangle(); } public: /// <summary> /// A wrapper class for use with storing Fonts in a ListBox. Since ListBox uses the /// ToString() of its items for the text it displays, this class is needed to return /// the name of the font, rather than its ToString() value. /// </summary> ref class ListBoxFontItem { public: System::Drawing::Font^ Font; ListBoxFontItem( System::Drawing::Font^ f ) { Font = f; } virtual String^ ToString() override { return Font->Name; } }; }; [STAThread] int main() { Application::Run( gcnew Form1 ); }
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
