PictureBox.LoadAsync Method (String)

If the url parameter indicates a local file, the recommended format is a local file path. For example, an image file named myPicture.jpglocated atc:\ would be accessed by passing c:\myPicture.jpg for the url parameter. A full path, such as http://www.contoso.com/path/images/image.jpg, or a relative path, such as ./images/image.jpg, can be used. If a relative path is used, it will be considered relative to the working directory. A call to the Load method sets the ImageLocation property to the value of url.

A call to the LoadAsync method sets the ImageLocation property to the value of url. Besides calling the LoadAsync method, you must set the WaitOnLoad property to false to load an image asynchronously. When you load an image asynchronously, you can handle the LoadProgressChanged event to determine the progress of an image load or the LoadCompleted event to determine when an image load has completed. If an error occurs during an asynchronous image-loading operation, it will be caught and reported by the Error property of the AsyncCompletedEventArgs.

The following code example demonstrates how to use the LoadAsync method. To run this example, paste the following code into a Windows Form that contains a PictureBox named pictureBox1 and a Button named startLoadButton. Make sure that the Click event for the button is associated with the startLoadButton_Click method in this example. You must change the image file path to a path that is valid on your system.

private void startButton_Click(object sender, EventArgs e)
{
    // Ensure WaitOnLoad is false.
    pictureBox1.WaitOnLoad = false;

    // Load the image asynchronously.
    pictureBox1.LoadAsync(@"http://localhost/print.gif");
}

.NET Framework

.NET Framework Client Profile

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference