create 2d barcode vb.net PAINT EVENTS in C#

Generating Data Matrix in C# PAINT EVENTS

PAINT EVENTS
Encoding Data Matrix ECC200 In Visual C#
Using Barcode drawer for VS .NET Control to generate, create Data Matrix ECC200 image in .NET framework applications.
www.OnBarcode.com
Decoding Data Matrix In C#.NET
Using Barcode decoder for .NET framework Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
Now that we can load multiple images into our album, we need a way to make them appear in the window. In previous chapters, we have simply assigned the selected photo to the Image property of our PictureBox control and relied on the .NET Framework to deal with the rest. The framework will still do most of the work, but now we need to identify which image from our album should be drawn.
Draw QR-Code In Visual C#.NET
Using Barcode creation for .NET Control to generate, create Denso QR Bar Code image in Visual Studio .NET applications.
www.OnBarcode.com
Creating GS1 - 13 In Visual C#.NET
Using Barcode creation for Visual Studio .NET Control to generate, create GS1 - 13 image in .NET applications.
www.OnBarcode.com
PAINT EVENTS
Printing Barcode In Visual C#.NET
Using Barcode printer for .NET framework Control to generate, create Barcode image in .NET framework applications.
www.OnBarcode.com
Paint Linear Barcode In Visual C#
Using Barcode drawer for .NET Control to generate, create Linear 1D Barcode image in .NET applications.
www.OnBarcode.com
As in previous Microsoft development environments, such drawing is called painting in .NET. You may have noticed in chapter 3 that the Control class provides a Paint event for custom painting of a control. The event name is one piece of the support provided for each event in the .NET Framework. While we have seen these pieces in our previous use of events, this is a good place to list them more formally. The following support is required in order to define and support an event. A class that defines the event data. This is either the System.EventArgs class or a class derived from System.EventArgs. The event data for the Paint event is defined by the PaintEventArgs class. We will discuss the contents of the PaintEventArgs class in chapter 7. A delegate for the event. This delegate is used by Visual Studio .NET to add the event handler in the InitializeComponent method. By convention, the name of this delegate is the event name followed by the string EventHandler. The Paint event is supported by the PaintEventHandler delegate. The creation of delegates is discussed in chapter 9. A class that raises the event. This class must define the event and provide a method to raise the event. By convention the method to raise the event is the string On followed by the event name. The protected OnPaint method raises the Paint event. For painting of controls, the Control class defines the Paint event. Within the definition of this class, the event is defined using the event keyword in C#.
Barcode Generation In Visual C#
Using Barcode creator for Visual Studio .NET Control to generate, create Barcode image in VS .NET applications.
www.OnBarcode.com
MSI Plessey Printer In Visual C#.NET
Using Barcode creation for Visual Studio .NET Control to generate, create MSI Plessey image in Visual Studio .NET applications.
www.OnBarcode.com
public event PaintEventHandler Paint;
Data Matrix ECC200 Creation In Java
Using Barcode generation for Android Control to generate, create Data Matrix image in Android applications.
www.OnBarcode.com
Draw DataMatrix In None
Using Barcode drawer for Microsoft Excel Control to generate, create Data Matrix image in Microsoft Excel applications.
www.OnBarcode.com
DRAWING THE CURRENT PHOTOGRAPH Returning to our code, we need a way to draw the appropriate photograph in our album. We could handle the Paint event directly in our Form or PictureBox control for this purpose. Instead, since the MainForm class derives from the Form class, we can override the method that raises the event directly. This technique is preferred where possible to avoid the extra overhead of creating and invoking an event handler. In this case, we will override the protected OnPaint method to handle the Paint event.
Creating Barcode In Objective-C
Using Barcode printer for iPhone Control to generate, create Barcode image in iPhone applications.
www.OnBarcode.com
Create ANSI/AIM Code 39 In None
Using Barcode printer for Font Control to generate, create Code 39 Full ASCII image in Font applications.
www.OnBarcode.com
CHA PTE R 6
Barcode Encoder In Visual Basic .NET
Using Barcode printer for VS .NET Control to generate, create Barcode image in .NET applications.
www.OnBarcode.com
Barcode Decoder In None
Using Barcode reader for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
COMMON FILE DIALOGS
Data Matrix 2d Barcode Printer In Objective-C
Using Barcode printer for iPhone Control to generate, create Data Matrix 2d barcode image in iPhone applications.
www.OnBarcode.com
Paint Barcode In Java
Using Barcode creator for Eclipse BIRT Control to generate, create Barcode image in BIRT applications.
www.OnBarcode.com
Set the version number of the MyPhotos application to 6.4. OVERRIDE THE ONPAINT METHOD Action 1 In the MainForm.cs file override the OnPaint method. Only paint an image if the album is not empty. Note: The three comments here are implemented in the subsequent steps. In all cases, the status bar is invalidated. Result
Data Matrix ECC200 Creation In None
Using Barcode encoder for Font Control to generate, create Data Matrix 2d barcode image in Font applications.
www.OnBarcode.com
Barcode Printer In .NET
Using Barcode creator for Reporting Service Control to generate, create Barcode image in Reporting Service applications.
www.OnBarcode.com
protected override void OnPaint( PaintEventArgs e) { if (_album.Count > 0) { // Paint the current image // Update the status bar } else { // Indicate the album is empty } statusBar1.Invalidate();
Barcode Reader In Java
Using Barcode reader for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
Encoding Data Matrix In Java
Using Barcode printer for Java Control to generate, create Data Matrix image in Java applications.
www.OnBarcode.com
Call OnPaint in the base class.
base.OnPaint(e);
Note: This call is required to ensure that any Paint event handlers registered with the Form are called. As mentioned in chapter 5, the base keyword refers to the base class of the current object. 4 Paint the current image by setting the Image property of the pbxPhoto control. Update the status bar to hold the appropriate information about the image. Note: The code here is similar to what we used in our menuLoad_Click event handler in chapter 4. 6 When no images are present, clear the screen and display an appropriate status bar message.
// Paint the current image Photograph photo = _album.CurrentPhoto; pbxPhoto.Image = photo.Image; // Update the status bar. sbpnlFileName.Text = photo.FileName; sbpnlImageSize.Text = String.Format ("{0:#} x {1:#}", photo.Image.Width, photo.Image.Height ); statusBar1.ShowPanels = true; // Indicate the album is empty pbxPhoto.Image = null; statusBar1.Text = "No Photos in Album"; statusBar1.ShowPanels = false;
DISPLAYING THE CURRENT POSITION Before we see our changes in action, it would be nice to have some indication of our current position within the album and the total album size in the window. We can do this by adding a new StatusBarPanel to hold this information, as detailed by the following steps.
Copyright © OnBarcode.com . All rights reserved.