How to zoom image using mouse wheel?

For Dynamic .NET TWAIN v6.x and lower versions only, for V7.x+ please refer to http://developer.dynamsoft.com/dnt/kb

Dynamic .NET TWAIN allows you to zoom image using hot keys. Below is a simple sample in C# to use Ctrl key + mouse wheel to zoom images in Dynamic .NET TWAIN.

private void btnScan_Click(object sender, EventArgs e)
        {
            dynamicDotNetTwain1.SelectSource();
            dynamicDotNetTwain1.OpenSource();
           //shows only the current image
            dynamicDotNetTwain1.SetViewMode(-1, -1);
           // enable zooming image using hot key.
            dynamicDotNetTwain1.EnableInteractiveZoom = true;
            dynamicDotNetTwain1.IfShowUI = false;            
            dynamicDotNetTwain1.AcquireImage();
        }

References:
SetViewMode
EnableInteractiveZoom