Android calculates the transparency of the layout background

1, #ff000000 This is 16 color code, the first 2 FF is transparent, the last 6 bits are color values (000000 is black, FFFFFF is white, can be obtained by software such as PS).

2, the transparency is divided into 256 order (0-255), the computer uses the 16 notation as (00-FF).

      Transparent is 0 order, opaque is 255 order, if 50% transparent is 127 order (256 of course is 128, but because it is starting from 0, so it is actually 127).

3, 10 255 conversion into 16 binary is ff,127 converted into 16 binary is 7f, #7f000000 represents 50% transparency of the black.

(written #50000000 of course not) the binary conversion can be used with the Win7 to bring the calculator (to scientific type). Example: 25% a red "#3ff70000 of transparency

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Android calculates the transparency of the layout background