如何从代码中检索和使用样式属性？

Question

I have defined a theme in style.xml file.

    <style name="ThemePurple" parent="AppTheme.NoActionBar">
        <item name="colorPrimary">@color/colorPurple</item>
        <item name="colorPrimaryDark">@color/colorPurpleDark</item>
        <item name="colorAccent">@color/colorPurpleAccent</item>
    </style>

I want to use the colorPrimary of this theme to a textView in a recyclerView . I've tried this:

int[] attrs = {android.R.attr.colorPrimary};
TypedArray typedArray = mContext.obtainStyledAttributes(R.style.ThemePurple, attrs);
holder.titleView.setTextColor(typedArray.getColor(0, Color.BLACK));
typedArray.recycle();

But this is not working..

Answer 1

not android.R.attr.colorPrimary , but just R.attr.colorPrimary

android prefix means you want to get built-in value, eg android:colorPrimary

you are using compat lib (AndroidX probably) which delivers newer attributes to older system versions, so these parameteres are in fact "custom", without android: prefix

Answer 2

For Kotlin :

val typedValue = TypedValue()
context.theme.resolveAttribute(android.R.attr.colorPrimary, typedValue, true)
holder.titleView.setTextColor(typedValue.data)

For Java:

TypedValue typedValue = new TypedValue();
context.getTheme().resolveAttribute(android.R.attr.colorPrimary, typedValue, true);
holder.titleView.setTextColor(typedValue.data);