iOS Question Static size of image regardless of plateform

[Yvon Steinthal]

Hello,

So the title says it all, I am trying to show a picture in iOS that has exacly the same physical size on iPhone, iPad...
I am trying to find the DPI or PPI of each device but i am very much unsuccessful...
Any ideas?

Y.

 

[Erel]

iOS takes care of the scale internally. So the size of a 160 x 160 ImageView will be inch x inch.

This might not be 100% accurate on all devices. Try it.

 

[Yvon Steinthal]

Hi Erel,

What i ended up doing, and correct me if im wrong in doing it this way.
I made a list of known device size (ex: 4.7',5.5',5.8'...) and used the good old math to figure a better approximate dpi.

    Dim firstcrossoffsety As Double = size 'This is where i put the 4.7 or 5.5 , the ACTUAL size of the device
    Dim diagonal As Double = Power(GetDeviceLayoutValues.Width,2)+Power(GetDeviceLayoutValues.Height,2)
    diagonal = Sqrt(diagonal)
  
    Dim pixperinch As Double = diagonal / firstcrossoffsety
    Dim pixpermm As Double = pixperinch/25.4

I am showing a ruler, with millimeters, it needs to show the best measures regardless if its on a iPAD or iPHONE.
I can't use the "GetDeviceLayoutValues.DeviceApproximateScreenSize" as it returns a value that is not the real...

ex: returns 8.0 when in fact it should return 9.7

For users i added a Plus and Minus button in order to play with the size in the case my calculations are wrong on the first try.

 

[Erel]

This is probably your best option. There is no API in iOS to get the exact dpi value (there is such an API in Android though it is not always 100% accurate).