there is no image in texture paint blender 2.82 In blender 2.82 what I expected was there should be an image in the viewport so that I can paint, chosing part of image as I wanted, but I can't do that because there's no image showing.

Is there any hotkey or UI to show image on viewport?
For this, you need to load a texture in the texture subpanel of the Bursh settings panel, and set its mapping to Stencil: