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)