Got US B1/B2 visa first time I applied but when I applied for a Canadian visit visa, was denied the first time- reason no ties from where I applied, US. I applied for a visit visa once I got back to the Philippines and was granted one. They look at the "ties" that you have. In the US I was a tourist and the officer did not believe I will go back to the US even when I showed him my return ticket which would be from the US. In the Philippines I have a good job to go back to, so that probably is the reason I was approved for the visa. Canadian visa officers look for "ties", something that would make the applicant want to go back to once the allowed visit is over.
Sometimes it does not happen that way.. Both my parents are government employees. My dad even has travel documents signed by the Department of Transportation and Communication because he works at the Airport. My mom is a college professor teaching in one of the state university in the Philippines. Both have strong "ties" as both are still working and not yet of retiring age.. although they can be considered part of the early retirees.. both are 54 years old..
We have documents showing that they have this x-amount of cash and other assets that could support them on their visit to Canada.. Plus my Aunt has sent them an invitation letter stating that she'll shoulder the cost of their stay.. she even included her bank statement in the invitation letter..
I guess my parents were not that lucky at the time they applied.. It all depends on the visa officer