Paths: Drawings on Macro-Vision | in Visual Basic .NET

Drawer QR Code 2d barcode in Visual Basic .NET Paths: Drawings on Macro-Vision |

Paths: Drawings on Macro-Vision |
QR Code JIS X 0510 Encoder In VB.NET
Using Barcode generator for VS .NET Control to generate, create QR Code image in VS .NET applications.
www.OnBarcode.com
Scan QR Code In Visual Basic .NET
Using Barcode reader for Visual Studio .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
Keeping It Regional
Universal Product Code Version A Encoder In Visual Basic .NET
Using Barcode creation for .NET framework Control to generate, create UPC-A Supplement 2 image in .NET framework applications.
www.OnBarcode.com
Paint 1D In Visual Basic .NET
Using Barcode drawer for VS .NET Control to generate, create 1D Barcode image in .NET applications.
www.OnBarcode.com
Usually, when you draw images, you have the entire visible canvas to work with. (You can draw images and shapes off the edge of the canvas if you want, but if a tree draws an image in the forest and no one is there to admire it, does it appear ) But there are times when you may want only a portion of what you draw to appear. Windows uses this method itself to save time. When you obscure a window with another one, and then expose the hidden window, the application has to redraw everything that appeared on the form or window. But if only a portion of that background window was hidden and then made visible again, why should the program go through the trouble of drawing everything again It really has to redraw only the part that was hidden, the part that was in the hidden region. A region specifies an area to be drawn on a surface. And regions aren t limited to boring rectangular shapes. You can design a region based on simple shapes, or you can combine existing regions into more complex regions. For instance, if you have two rectangular regions, you can overlap them and request a new combined region that contains (1) all of the original two regions; (2) the original regions but without the overlapped parts; or (3) just the overlapped parts. Figure 18-11 shows these combinations.
Generating Barcode In Visual Basic .NET
Using Barcode generator for VS .NET Control to generate, create Barcode image in Visual Studio .NET applications.
www.OnBarcode.com
Creating ECC200 In VB.NET
Using Barcode encoder for .NET Control to generate, create Data Matrix ECC200 image in .NET applications.
www.OnBarcode.com
Original regions
EAN128 Generator In VB.NET
Using Barcode generator for .NET Control to generate, create UCC-128 image in Visual Studio .NET applications.
www.OnBarcode.com
MSI Plessey Creator In VB.NET
Using Barcode creation for VS .NET Control to generate, create MSI Plessey image in Visual Studio .NET applications.
www.OnBarcode.com
Union
Make QR Code ISO/IEC18004 In None
Using Barcode generator for Office Word Control to generate, create QR Code 2d barcode image in Word applications.
www.OnBarcode.com
Recognizing QR Code 2d Barcode In VB.NET
Using Barcode recognizer for .NET framework Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
Xor (XOR)
Code-39 Maker In None
Using Barcode maker for Word Control to generate, create Code 39 image in Microsoft Word applications.
www.OnBarcode.com
Make Matrix In C#.NET
Using Barcode creation for .NET Control to generate, create Matrix 2D Barcode image in .NET framework applications.
www.OnBarcode.com
Intersect (AND)
Encode USS Code 128 In None
Using Barcode maker for Online Control to generate, create Code 128B image in Online applications.
www.OnBarcode.com
EAN 128 Printer In None
Using Barcode creator for Software Control to generate, create UCC-128 image in Software applications.
www.OnBarcode.com
During drawing operations, regions are sometimes referred to as clipping regions because any content drawn outside the region is clipped off and thrown away. The following code draws an image, but masks out an ellipse in the middle by using (tada!) a graphics path to establish a custom clipping region:
Encode Data Matrix 2d Barcode In VS .NET
Using Barcode encoder for Reporting Service Control to generate, create DataMatrix image in Reporting Service applications.
www.OnBarcode.com
Barcode Drawer In None
Using Barcode maker for Software Control to generate, create Barcode image in Software applications.
www.OnBarcode.com
' ----- Load the image. We'll show it smaller than normal. Dim splashImage As New Bitmap("SplashImage.jpg") Dim thePath As New Drawing2D.GraphicsPath( ) ' ----- Create an elliptical path that is the size of the ' output image. thePath.AddEllipse(20, 20, splashImage.Width \ 2, _ splashImage.Height \ 2) ' ----- Replace the original clipping region that covers ' the entire canvas with just the rectangular region. e.Graphics.SetClip(thePath, Drawing2D.CombineMode.Replace)
Encoding ECC200 In Java
Using Barcode creator for Java Control to generate, create ECC200 image in Java applications.
www.OnBarcode.com
USS Code 128 Scanner In Java
Using Barcode scanner for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
|
Making Barcode In Objective-C
Using Barcode creation for iPhone Control to generate, create Barcode image in iPhone applications.
www.OnBarcode.com
Barcode Reader In None
Using Barcode decoder for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
18: User Interface
' ----- Draw the image, which will be clipped. e.Graphics.DrawImage(splashImage, 20, 20, _ splashImage.Width \ 2, splashImage.Height \ 2) ' ----- Clean up. thePath.Dispose( )
The output for this code appears in Figure 18-12.
Regions are also useful for hit testing. If you draw a non-rectangular image on a form, and you want to know when the user clicks on the image, but not on any pixel just off the image, you can use a region that is the exact shape of the image to test for mouse clicks.
Twisting and Turning with Transformations
Normally, anything you draw on the graphics canvas is laid down directly on the bitmap surface. It s like a giant grid, and your drawing commands are basically dropping colored inks directly into each grid cell. The Graphics object also gives you the ability to pass your drawing commands through a geometric transformation before their output goes to the canvas surface. For instance, a rotation transformation would rotate your lines, shapes, and text by the amount you specify (in degrees), and then apply the result to the surface. Figure 18-13 displays the results of the following code, which applies two translations: (1) moving the (0, 0) origin right by 100 pixels and down by 75 pixels; and (2) adding a clockwise rotation of 270 degrees.
e.Graphics.DrawString("Normal", _ SystemFonts.DefaultFont, Brushes.Black, 10, 10) e.Graphics.TranslateTransform(100, 75) e.Graphics.RotateTransform(270) e.Graphics.DrawString("Rotated", _ SystemFonts.DefaultFont, Brushes.Black, 10, 10) e.Graphics.ResetTransform( )
Twisting and Turning with Transformations |
Transformations are cumulative; if you apply multiple transformations to the canvas, any drawing commands will pass through all of the transformations before arriving at the canvas. The order in which transformations occur is important. If the code we just ran had reversed the TranslateTransform and RotateTransform statements, the rotation would have altered the x, y coordinates for the entire canvas world. The subsequent translation of (100, 75) would have moved up the origin 100 pixels and then to the right 75 pixels. The Graphics class includes these methods that let you apply transformations to the world view of the canvas during drawing:
Copyright © OnBarcode.com . All rights reserved.