This documentation is archived and is not being maintained.

PictureBox.LoadProgressChanged Event

Occurs when the progress of an asynchronous image-loading operation has changed.

Namespace:  System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

public event ProgressChangedEventHandler LoadProgressChanged

The LoadProgressChanged occurs only when the image is loaded asynchronously by using one of the LoadAsync methods. The progress percentage of the image load is reported with the ProgressPercentage property of the ProgressChangedEventArgs.

Handle the LoadProgressChanged if you want to reflect the progress of an asynchronous image-loading operation in a ProgressBar or similar control. Use the ProgressPercentage property of the ProgressChangedEventArgs to update the progress value.

For more information about handling events, see Consuming Events.

The following code example demonstrates how to handle the LoadProgressChanged event. To run this example, paste the following code into a Windows Form that contains a PictureBox named pictureBox1, a Button named startLoadButton, and a ProgressBar named progressBar1. Make sure that the startLoadButton_Click method is associated with the Click event for the button and the pictureBox1_LoadProgressChanged method is associated with the LoadProgressChanged event for pictureBox1. 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.


void pictureBox1_LoadProgressChanged(object sender, 
    ProgressChangedEventArgs e)
    progressBar1.Value = e.ProgressPercentage;

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

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

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.