问题
I have a homescreen widget, with linear layout. I'm trying to set Alpha for the background during runtime using remote views, but the widget doesn't load.
I'm using this:
remoteView.setFloat(R.id.widget_background, "setAlpha", (float)0.7);
Setting background color or text color the same way, works. How can I set the background transparency using remote views?
回答1:
There is a simple solution using background color in hex. You have a color, for example RED - #ff0000
to set background red to your app widget, you can use:
widget.setInt(R.id.widget_list, "setBackgroundColor", Color.parseColor("#ff0000"));
for color transparency just add in front of your color how much color - transparency rapport you want, for example:
for 20% color will be #20ff0000:
for 85% color #85ff0000 wou'll have:
回答2:
1.You can use Style.xml to make a backgound transparent like below:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="Theme.Transparent" parent="android:Theme">
<item name="android:windowIsTranslucent">true</item>
<item name="android:windowBackground">@android:color/transparent</item>
<item name="android:windowContentOverlay">@null</item>
<item name="android:windowNoTitle">true</item>
<item name="android:windowIsFloating">true</item>
<item name="android:backgroundDimEnabled">false</item>
</style>
</resources>
Set this file as a theme of your widget. OR 2.Put 80 after # sign in your color code like this:#80000000 Hope it helps..You can use #80FFFFFF for background without any color.I have not tried it in code but may be its helpful.
回答3:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:background="@android:color/transparent">
<ImageView
android:id="@+id/widget_image"
android:layout_width="110sp"
android:layout_height="110sp"
android:layout_gravity="center"
android:src="@drawable/flashlight1" />
</LinearLayout>
Just set background of layout to transparent. Add below code. this worked for me.
android:background="@android:color/transparent"
回答4:
I used the following solution:
float opacity = 0.3f; //opacity = 0: fully transparent, opacity = 1: no transparancy
int backgroundColor = 0x000000; //background color (here black)
remoteView.setInt( R.id.loMain, "setBackgroundColor", (int)(opacity * 0xFF) << 24 | backgroundColor);
loMain is a main layout of my widget
If the main layout of the widget uses shape background (e.g. android:background="@drawable/shape_transparent") which has rounded corner then here is a more complex solution:
float transparency = 0.5f; //0...1
long colorFilter = 0x01000000L * (long)(255f * transparency);
try {
final Method[] declaredMethods = Class.forName("android.widget.RemoteViews").getDeclaredMethods();
final int len = declaredMethods.length;
if (len > 0) {
for (int m=0; m<len; m++ ) {
final Method method = declaredMethods[m];
if (method.getName().equals("setDrawableParameters")) {
method.setAccessible(true);
method.invoke(remoteView, R.id.loMain, true, -1, (int)colorFilter, PorterDuff.Mode.DST_OUT, -1);
break;
}
}
}
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (IllegalArgumentException e) {
e.printStackTrace();
}
You can play with variables alfa and colorFilter to meet your needs.
回答5:
Set transparent background of an imageview on Android
Above link is the best solution for this type of Background Color.
Below code for black:-
<color name="black">#000000</color>
Now if u want to use opacity than you can use below code :-
<color name="black">#99000000</color>
below for opacity code:-
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
来源：https://stackoverflow.com/questions/17187471/setting-transparency-for-widget-background