HomeSearch

WPF Image Example: PNG, JPG Files

Use the WPF Image control to display JPG, PNG files. Understand the BitmapImage type.

Image.

How can we render a picture in a WPF program? With an Image control, we display bitmaps of all types, including PNG and JPG. Other forms of images (drawings) are even supported. But this control has some complexity.

Example.

To begin, please create a WPF project and drag the Image control to your Window. Now edit the XAML markup for the Image element. Add a Loaded event handler by typing "Loaded". Visual Studio will create the Image_Loaded method.

In Image_Loaded,

we want to assign the Source property of the Image object. This is a little tricky. We first create a BitmapImage object. We then assign the Source property to the BitmapImage reference.

BitmapImage: Using the BitmapImage requires some nuance. We must call BeginInit() before, and EndInit() after, setting the UriSource.

Warning: If you omit the BeginInit and EndInit calls, nothing will happen. If you don't believe me, try it and find out.

Note: Please change the Uri object to point to a file that exists on your computer system.

Uri
Example markup: XAML <Window x:Class="WpfApplication11.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="MainWindow" Height="350" Width="525"> <Grid> <Image HorizontalAlignment="Left" Height="100" Margin="10,10,0,0" VerticalAlignment="Top" Width="100" Loaded="Image_Loaded"/> </Grid> </Window> Example code: C# using System; using System.Windows; using System.Windows.Controls; using System.Windows.Media.Imaging; namespace WpfApplication11 { /// <summary> /// Interaction logic for MainWindow.xaml /// </summary> public partial class MainWindow : Window { public MainWindow() { InitializeComponent(); } private void Image_Loaded(object sender, RoutedEventArgs e) { // ... Create a new BitmapImage. BitmapImage b = new BitmapImage(); b.BeginInit(); b.UriSource = new Uri("c:\\plus.png"); b.EndInit(); // ... Get Image reference from sender. var image = sender as Image; // ... Assign Source. image.Source = b; } } }

Simple shapes.

For simple shapes, consider the Ellipse or Rectangle controls. These are easier to use than Image, but only support simple visual effects. A shape (or Image) can also be transformed with RenderTransform.EllipseRectangleRenderTransform

Summary.

Rarely are programs simple. But they tend to be composed of simple parts. And the Image type is also composed of simple parts. With it, we display pictures and other graphics—with a minimum of custom code.
Home
Dot Net Perls
© 2007-2019 Sam Allen. All rights reserved. Written by Sam Allen, info@dotnetperls.com.