This article has been
excerpted from book "Graphics Programming with GDI+".
Texture brushes allow us to use an image as a brush and fill GDI+ objects with
the brush. Texture brushes are useful when you need to fill a graphics object
with images in a pattern such as tile. In this section we will discuss how to
create and use texture brushes in GDI+.
FIGURE 4.5: The default hatch style rectangle
FIGURE 4.6: The LightDownwardDiagonal style with different colors
FIGURE 4.7: The DiagonalCross style
In the .NET Framework library, the TextureBrush class represents a texture
brush. Table 4.2 describes the properties of the TextureBrush class.
Let's create an application using textures brushes. We create a Windows
application. We also add a context menu to the form, along with five context
menu items. The final looks like Figure 4.8.
TABLE 4.2: TextureBrush properties
Return the Image
object associated with a TextureBrush
Represents a Matrix
object that defines a local geometric transformation for the image.
Represents a WrapMode
enumeration that indicates the wrap mode for a texture brush.
FIGURE 4.8: The texture brush application
Note: The WrapMode enumeration represents the wrap mode for a texture
brush. It has five members: Clamp, Tile, TileFlipX, TileFlipY and TileFlipXY.
These members are described later, in Table 4.7.
Now we add a class-level variable of TextureBrush type to the application:
private TextureBrush txtrBrush =
The next step is to create a texture brush from an image and fill a rectangle
with that brush. We create an Image object on the form's load event handler from
the file Image.gif, which is used to create a TextureBrush object. On the form's
paint event handler, we call the FillRectangle method to fill the rectangle with
the texture. Listing 4.8 shows the form's load and paint event handler. Note
that our rectangle is the ClientRectangle of the form.
LISTING 4.8: Creating a texture brush and filling a rectangle
private void Form1_Load (object
sender, System.EventArgs e)
//Create an image from a file
Image img = new
//Create a texture brush from an image
txtrBrush = new TextureBrush
private void Form1_Paint (object
sender, System.Windows.Forms.PaintEventArgs e)
Graphics g = e.Graphics;
//Fill a rectangle with a texture brush
g.FillRectangle (txtrBrush, ClientRectangle);
Now we can add event handlers for the context menu items as shown in Listing
4.9. As you can see from this code, we simply set the WrapMode property of the
LISTING 4.9: TextureBrush's context menu event handlers
private void Clamp_Click(object
sender, System.EventArgs e)
txtrBrush.WrapMode = WrapMode.Clamp;
void Title_Click(object sender,
txtrBrush.WrapMode = WrapMode.Tile;
void TitleFlipX_Click(object sender,
txtrBrush.WrapMode = WrapMode.TileFlipX;
void TileFlipY_Click(object sender,
txtrBrush.WrapMode = WrapMode.TileFlipY;
void TileFlipXY_Click(object sender,
txtrBrush.WrapMode = WrapMode.TileFlipXY;
Finally, we need to load the context menu on the right mouse click event
handler. As Listing 4.10 shows, we simply set the ContextMenu property of the
LISTING 4.10: The right mouse button click event handler
private void Form1_MouseDown(object
sender, System.Windows.Forms.MouseEventArgs e)
if (e.Button == MouseButtons.Right)
this.ContextMenu = contextMenu1;
Now let's run the application. Figure 4.9 shows default (tiled) output from the
program. The entire client rectangle is filled with texture.
If we right-click on the form and select the Clamp menu item, we get Figure
Now let's select the TileFlipY option, which generates Figure 4.11.
You can try other options on your own!
FIGURE 4.9: Using Texture brushes
FIGURE 4.10: Claming a texture
FIGURE 4.11: The TileFlipY texture option
Hope the article would have helped you in understanding Texture Brushes in GDI+. Read other articles on GDI+ on the website.
| ||This book teaches
.NET developers how to work with GDI+ as they develop applications
that include graphics, or that interact with monitors or printers.
It begins by explaining the difference between GDI and GDI+, and
covering the basic concepts of graphics programming in Windows. |