(Idk if my title is correct, because when I google it, there is no related result I guess)

I am not sure how to explain it correctly, but I am making a plain 2D, tile based, tactic game in windows phone 8 using monogame. I want to make my map is "slideable". With "slidable" I mean I can draw larger images (in total) than my screen and then slide it so I can view a certain area of the drawn images

Example : I have a screen which dimension is 1280x720. I have a 1500x1500px image, which consists of 15 tiles, which is 100x100px each, which each tiles is redrawn each times the "Draw" is called. If the image is larger than the screen, the displayed area will be trimmed and of course, making a 220x780px area that is unseenable. The only way to see all of it is through "sliding" the screen around, so I can see all the area.

My question is : How to make that happen? Because in default, the screen is unslideable and the image remains trimmed.

Sorry if my question and explanation is not clear enough. Clarify it as much as you like. Thank you.