Android Visual spec-spacing specification and text spec unit conversion (DIP, SP, px)

http://blog.csdn.net/shimiso/article/details/29826073

1, Dip and px

When the Android engineer writes the page, the margin value is in dip, and the visual designer usually controls the margin value through the PX, what is the difference between different units? Look at the following parameters.

Visual measurement results between dip and PX under WVGA (800x480):

1dip=2px	9dip=14px	17dip=26px
2dip=3px	10dip=15px	18dip=27px
3dip=5px	11dip=17px	19dip=29px
4dip=6px	12dip=18px	20dip=30px
5dip=8px	13dip=20px	21dip=31px
6dip=9px	14dip=21px
7dip=11px	15dip=23px
8dip=12px	16dip=24px

According to the above values can be obtained in a WVGA dip and PX Conversion formula (2N for any even, 2n-1 represents the small and even 1 odd):

Conversion formula between dip and PX:

A. 2N + 2N/2 = PX

B. (2n-1) + 2N/2 = PX

Note: An even value dip is 1.5 times times equal to the corresponding PX value, and the spacing between the even values and the odd element setting is centered with the 1px error, which may not be very aesthetically pleasing to look at (e.g.).

A and B center align with a value difference, and C and D can be perfectly aligned.

However, the probability of this situation is very small, only in the narrow page of the time common to meet when the emergency treatment can also solve the problem, but if the design at the beginning of attention, the back of the narrow buckle will not be the problem, but also eliminate the emergency treatment time, to a certain extent can improve efficiency.

Visual measurement results between dip and PX under HVGA (320x480):

1dip=1px	9dip=9px	17dip=17px
2dip=2px	10dip=10px	18dip=18px
3dip=3px	11dip=11px	19dip=19px
4dip=4px	12dip=12px	20dip=20px
5dip=5px	13dip=13px	21dip=21px
6dip=6px	14dip=14px
7dip=7px	15dip=15px
8dip=8px	16dip=16px

The result of the above parameter is that the dip is equal to the PX value.

From the above, the visual designer in the WVGA (480x800) mode design, the recommended optimal spacing is: 12px, 18px, 24px, 30px, 36px, 42px, 48px, because the dip, PX value in the HVGA\WVGA corresponding are even, Each element can be the most stringent alignment.

Second, SP and px

Visual measurement results between SP and px under WVGA (800x480):

7sp=11px	15sp=23px	23sp=35px
8sp=12px	16sp=24px	24sp=36px
9sp=14px	17sp=26px	25sp=38px
10sp=15px	18sp=27px	26sp=39px
11sp=17px	19sp=29px	27sp=41px
12sp=18px	20sp=30px	28sp=42px
13sp=20px	21sp=31px	29sp=44px
14sp=21px	22sp=33px	30sp=45px

The results obtained from the above parameters are as follows:

The conversion formula between SP and PX is the same as the conversion formula for dip and PX:

A. 2N + 2N/2 = PX

B. (2n-1) + 2N/2 = PX

Results of conversion between SP and px under HVGA (320x480):

7sp=7px	15sp=15px	23sp=23px
8sp=8px	16sp=16px	24sp=24px
9sp=9px	17sp=17px	25sp=25px
10sp=10px	18sp=18px	26sp=26px
11sp=11px	19sp=19px	27sp=27px
12sp=12px	20sp=20px	28sp=28px
13sp=13px	21sp=21px	29sp=29px
14sp=14px	22sp=22px	30sp=30px

The result of the above parameter is that the SP value is equal to the PX value.

From the above, the visual designer in the WVGA (480x800) mode design, the recommended commonly used best font size is: 18px, 24px, 30px, 36px, 42px, in some need to strictly align the position, these parameters of the text is not a problem, of course, the other font size is also available, After all, not all of the text in the app needs to be strictly aligned.

Knowledge Popularization:

SP, dip,android default units, can be adapted to different screen sizes, the same font size, different screen sizes display different visual effects.

PX is a fixed pixel value and does not actively adapt to the screen size, and the visual effect is the same as the screen size.

Android Visual spec-spacing specification and text spec unit conversion (DIP, SP, px)