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+---
+title: "Overriding the OnPaint Method"
+ms.date: "03/30/2017"
+dev_langs: 
+  - "csharp"
+  - "vb"
+helpviewer_keywords: 
+  - "Paint event [Windows Forms], handling in Windows Forms custom control"
+  - "OnPaint method [Windows Forms], overriding in Windows Forms custom controls"
+ms.assetid: e9ca2723-0107-4540-bb21-4f5ffb4a9906
+---
+# Overriding the OnPaint Method
+The basic steps for overriding any event defined in the .NET Framework are identical and are summarized in the following list.  
+  
+#### To override an inherited event  
+  
+1. Override the protected `On`*EventName* method.  
+  
+2. Call the `On`*EventName* method of the base class from the overridden `On`*EventName* method, so that registered delegates receive the event.  
+  
+ The <xref:System.Windows.Forms.Control.Paint> event is discussed in detail here because every Windows Forms control must override the <xref:System.Windows.Forms.Control.Paint> event that it inherits from <xref:System.Windows.Forms.Control>. The base <xref:System.Windows.Forms.Control> class does not know how a derived control needs to be drawn and does not provide any painting logic in the <xref:System.Windows.Forms.Control.OnPaint%2A> method. The <xref:System.Windows.Forms.Control.OnPaint%2A> method of <xref:System.Windows.Forms.Control> simply dispatches the <xref:System.Windows.Forms.Control.Paint> event to registered event receivers.  
+  
+ If you worked through the sample in [How to: Develop a Simple Windows Forms Control](how-to-develop-a-simple-windows-forms-control.md), you have seen an example of overriding the <xref:System.Windows.Forms.Control.OnPaint%2A> method. The following code fragment is taken from that sample.  
+  
+```vb  
+Public Class FirstControl  
+   Inherits Control  
+  
+   Public Sub New()  
+   End Sub  
+  
+   Protected Overrides Sub OnPaint(e As PaintEventArgs)  
+      ' Call the OnPaint method of the base class.  
+      MyBase.OnPaint(e)  
+      ' Call methods of the System.Drawing.Graphics object.  
+      e.Graphics.DrawString(Text, Font, New SolidBrush(ForeColor), RectangleF.op_Implicit(ClientRectangle))  
+   End Sub  
+End Class
+```  
+  
+```csharp  
+public class FirstControl : Control {  
+   public FirstControl() {}  
+   protected override void OnPaint(PaintEventArgs e) {  
+      // Call the OnPaint method of the base class.  
+      base.OnPaint(e);  
+      // Call methods of the System.Drawing.Graphics object.  
+      e.Graphics.DrawString(Text, Font, new SolidBrush(ForeColor), ClientRectangle);  
+   }
+}
+```  
+  
+ The <xref:System.Windows.Forms.PaintEventArgs> class contains data for the <xref:System.Windows.Forms.Control.Paint> event. It has two properties, as shown in the following code.  
+  
+```vb  
+Public Class PaintEventArgs  
+   Inherits EventArgs  
+   ...  
+   Public ReadOnly Property ClipRectangle() As System.Drawing.Rectangle  
+      ...  
+   End Property  
+  
+   Public ReadOnly Property Graphics() As System.Drawing.Graphics  
+      ...  
+   End Property
+   ...  
+End Class  
+```  
+  
+```csharp  
+public class PaintEventArgs : EventArgs {  
+...  
+    public System.Drawing.Rectangle ClipRectangle {}  
+    public System.Drawing.Graphics Graphics {}  
+...  
+}  
+```  
+  
+ <xref:System.Windows.Forms.PaintEventArgs.ClipRectangle%2A> is the rectangle to be painted, and the <xref:System.Windows.Forms.PaintEventArgs.Graphics%2A> property refers to a <xref:System.Drawing.Graphics> object. The classes in the <xref:System.Drawing?displayProperty=nameWithType> namespace are managed classes that provide access to the functionality of GDI+, the new Windows graphics library. The <xref:System.Drawing.Graphics> object has methods to draw points, strings, lines, arcs, ellipses, and many other shapes.  
+  
+ A control invokes its <xref:System.Windows.Forms.Control.OnPaint%2A> method whenever it needs to change its visual display. This method in turn raises the <xref:System.Windows.Forms.Control.Paint> event.  
+  
+## See also
+
+- [Events](https://docs.microsoft.com/dotnet/standard/events/index)
+- [Rendering a Windows Forms Control](rendering-a-windows-forms-control.md)
+- [Defining an Event](defining-an-event-in-windows-forms-controls.md)