I want to change the hex color value of a color variable and colorAccent color defined in the colors.xml file by MainActivity.java code.
What code should I write in the java file inside a method or a switch or if/else statement to change it?
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3The resources are immutable, so you can't change their values. Why do you need to change them tho ?– Aousaf RashidCommented Jan 8, 2020 at 9:24
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1put if-else use the different color key. you can not change the color value– TejasCommented Jan 8, 2020 at 9:24
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you could create different theme configuration, and switch between them programmatically .– nazmulCommented Jan 8, 2020 at 9:30
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@Aousafrashid so the resources are immutable, then i will define a different color variable with desired value to it but what about the colorAccent ? how do I change it Via java code– SHOONYACommented Jan 8, 2020 at 9:35
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@nazmul how do I create a different theme configuration ? please write an answer or refer me one– SHOONYACommented Jan 8, 2020 at 9:37
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2 Answers
You should use themes and styles for changing color values. See: Styles and Themes
Basically, you should declare the color in styles.xml:
<style name="GreenText" parent="TextAppearance.AppCompat">
<item name="android:textColor">#00FF00</item>
</style>
<style name="RedText" parent="TextAppearance.AppCompat">
<item name="android:textColor">#ff0000</item>
</style>
Then declare which theme to use in onCreate (before setContentView()):
switch (theme) {
case 1:
setTheme(R.style.Green);
break;
case 2:
setTheme(R.style.Red);
break;
}
Edit:
You can change the theme during onCreate() only - If you want to change it afterwards, during runtime, you will have to recreate your activity by calling recreate()
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what about the colorAccent color? how to change it programatically– SHOONYACommented Jan 8, 2020 at 9:40
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as @Black mamba posted, all color values are hardcoded. Therefore a way for you to deal with what you want to do is to prepare multiple different themes and switch them. Commented Jan 8, 2020 at 9:42
Unfortunately all color values (and other resources) inside the resources directory are hardcoded as static final ints. This means there is no way to change the values at runtime. You can however use one of the previously suggested solutions or have a look at this excellent
