Hi Gary,
Thanks for using Syncfusion products.
To use context menu with left click, we suggest you to use our Split Button control in which list of menu items can be displayed on left click of the button.
We have created a simple sample with Split Button and it can be downloaded from the attachment.
Kindly have a look at the sample and let us know if it helps.
Regard,
Meena
SplitButton_Forum_45cb7e36.zip