Graphics::BeginContainer

The Graphics::BeginContainer method begins a new graphics container.

Syntax

GraphicsContainer BeginContainer();

Return value

Type: GraphicsContainer

This method returns a value that identifies the container.

Remarks

Use this method to create nested graphics containers. Graphics containers are used to retain graphics state, such as transformations, clipping regions, and various rendering properties.

The Graphics::BeginContainer method returns a value of type GraphicsContainer. When you have finished using a container, pass that value to the Graphics::EndContainer method. The GraphicsContainer data type is defined in Gdiplusenums.h.

When you call the Graphics::BeginContainer method of a Graphics object, an information block that holds the state of the Graphics object is put on a stack. The Graphics::BeginContainer method returns a value that identifies that information block. When you pass the identifying value to the Graphics::EndContainer method, the information block is removed from the stack and is used to restore the Graphics object to the state it was in at the time of the Graphics::BeginContainer call.

Containers can be nested; that is, you can call the Graphics::BeginContainer method several times before you call the Graphics::EndContainer method. Each time you call the Graphics::BeginContainer method, an information block is put on the stack, and you receive an identifier for the information block. When you pass one of those identifiers to the Graphics::EndContainer method, the Graphics object is returned to the state it was in at the time of the Graphics::BeginContainer call that returned that particular identifier. The information block placed on the stack by that Graphics::BeginContainer call is removed from the stack, and all information blocks placed on that stack after that Graphics::BeginContainer call are also removed.

Calls to the Graphics::Save method place information blocks on the same stack as calls to the Graphics::BeginContainer method. Just as an Graphics::EndContainer call is paired with a Graphics::BeginContainer call, a Graphics::Restore call is paired with a Graphics::Save call.

Examples

The following example sets a clipping region for a Graphics object and begins a graphics container. It then sets an additional clipping region for the container and draws rectangles that demonstrate the effective clipping region inside the container.

VOID Example_BeginContainer(HDC hdc)
{
   Graphics graphics(hdc);

   // Set the clipping region for the Graphics object.
   graphics.SetClip(Rect(10, 10, 150, 150));

   // Begin a graphics container.
   GraphicsContainer container = graphics.BeginContainer();

   // Set an additional clipping region for the container.
   graphics.SetClip(Rect(100, 50, 100, 75));

   // Fill a red rectangle in the container.
   SolidBrush redBrush(Color(255, 255, 0, 0));
   graphics.FillRectangle(&redBrush, 0, 0, 400, 400);

   // End the container, and fill the same rectangle with blue. 
   graphics.EndContainer(container);
   SolidBrush blueBrush(Color(128, 0, 0, 255));
   graphics.FillRectangle(&blueBrush, 0, 0, 400, 400);

   // Set the clipping region to infinite, and draw the outlines 
   // of the two previous clipping regions.
   graphics.ResetClip();
   Pen blackPen(Color(255, 0, 0, 0), 2.0f);
   graphics.DrawRectangle(&blackPen, 10, 10, 150, 150);
   graphics.DrawRectangle(&blackPen, 100, 50, 100, 75);
}

Requirements

See also

Graphics

Graphics Containers

Graphics::EndContainer

Graphics::Restore

Graphics::Save

Using Graphics Containers