How to make a background 20% transparent on Androi

Question

How do I make the background of a Textview about 20% transparent (not fully transparent), where there is a color in the background (i.e. white)?

Answer 1

Here's a programmatic solution from @Aromero's answer to calculate the hexadecimal value for the alpha channel. :)

 public static void main(String[] args) throws Exception {
    final Scanner scanner = new Scanner(System.in);
    int transPerc;
    float fPerc;
    System.out.println("Enter the transparency percentage without % symbol:");
    while((transPerc=scanner.nextInt())>=0 && transPerc <=100){
        fPerc = (float) transPerc / 100;
        transPerc = Math.round(255 * fPerc);
        System.out.println("= " + Integer.toHexString(transPerc));
        System.out.print("another one please : ");
    }
    scanner.close();
}

Answer 2

Use the below code for black:

<color name="black">#000000</color>

Now if I want to use opacity then you can use the below code:

 <color name="black">#99000000</color> <!-- 99 is for alpha and others pairs zero's are for R G B -->

And below for opacity code: and all opacity level here

Hex Opacity Values

100% — FF
95% — F2
90% — E6
85% — D9
80% — CC
75% — BF
70% — B3
65% — A6
60% — 99
55% — 8C
50% — 80
45% — 73
40% — 66
35% — 59
30% — 4D
25% — 40
20% — 33
15% — 26
10% — 1A
5% — 0D
0% — 00

If you always to forget what code for transparency then you must have to see below link and no worry about to remember anything regarding transparent code :-

https://github.com/duggu-hcd/TransparentColorCode

textviewHeader.setTextColor(Color.parseColor(ColorTransparentUtils.transparentColor10(R.color.border_color)));

Answer 3

There is an XML value alpha that takes double values.

Since API 11+ the range is from 0f to 1f (inclusive), 0f being transparent and 1f being opaque:

• android:alpha="0.0" thats invisible

• android:alpha="0.5" see-through

• android:alpha="1.0" full visible

That's how it works.

Answer 4

<TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:alpha="0.9"
        />

Alpha ranges between 0(transparent) and 1(opaque) in Android API 11+

Answer 5

See Popularity below textView using this

     android:alpha="0.38"

XML

android:color="#3983BE00"    // Partially transparent sky blue

Dynamically

btn.getBackground().setAlpha(128); // 50% transparent

tv_name.getBackground().setAlpha(128); // 50% transparent

Where the INT ranges from 0 (fully transparent) to 255 (fully opaque).


  <TextView
            style="@style/TextAppearance.AppCompat.Caption"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:alpha="0.38"
            android:gravity="start"
            android:textStyle="bold"
            tools:text="1994|EN" />

android:alpha="0.38"

Text View alpha property set 0.38 to your textView visibility is faid 

Answer 6

You can manage color opacity changing the first 2 characters in the color definition:

#99000000

100% — FF
99% — FC
98% — FA
97% — F7
96% — F5
95% — F2
94% — F0
93% — ED
92% — EB
91% — E8

90% — E6
89% — E3
88% — E0
87% — DE
86% — DB
85% — D9
84% — D6
83% — D4
82% — D1
81% — CF

80% — CC
79% — C9
78% — C7
77% — C4
76% — C2
75% — BF
74% — BD
73% — BA
72% — B8
71% — B5

70% — B3
69% — B0
68% — AD
67% — AB
66% — A8
65% — A6
64% — A3
63% — A1
62% — 9E
61% — 9C

60% — 99
59% — 96
58% — 94
57% — 91
56% — 8F
55% — 8C
54% — 8A
53% — 87
52% — 85
51% — 82

50% — 80
49% — 7D
48% — 7A
47% — 78
46% — 75
45% — 73
44% — 70
43% — 6E
42% — 6B
41% — 69

40% — 66
39% — 63
38% — 61
37% — 5E
36% — 5C
35% — 59
34% — 57
33% — 54
32% — 52
31% — 4F

30% — 4D
29% — 4A
28% — 47
27% — 45
26% — 42
25% — 40
24% — 3D
23% — 3B
22% — 38
21% — 36

20% — 33
19% — 30
18% — 2E
17% — 2B
16% — 29
15% — 26
14% — 24
13% — 21
12% — 1F
11% — 1C

10% — 1A
9% — 17
8% — 14
7% — 12
6% — 0F
5% — 0D
4% — 0A
3% — 08
2% — 05
1% — 03
0% — 00