How can user attributes defined in XML be extracted within a custom View component?

To extract user attributes defined in XML within your custom View component in Android, you need to:

1. Define the attributes in the res/values/attrs.xml file:

<resources>
    <declare-styleable name="MyCustomView">
        <attr name="customAttr" format="string" />
        <attr name="customColor" format="color" />
    </declare-styleable>
</resources>

2. In the constructor of your custom View that takes AttributeSet attrs, obtain a TypedArray using the method context.obtainStyledAttributes(attrs, R.styleable.MyCustomView).

3. Extract the needed attributes from the TypedArray.

4. Remember to call recycle() on the TypedArray after use.

Example:

class MyCustomView @JvmOverloads constructor(
    context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : View(context, attrs, defStyleAttr) {

    var customText: String? = null
    var customColor: Int = Color.BLACK

    init {
        attrs?.let {
            val typedArray = context.obtainStyledAttributes(it, R.styleable.MyCustomView, 0, 0)
            customText = typedArray.getString(R.styleable.MyCustomView_customAttr)
            customColor = typedArray.getColor(R.styleable.MyCustomView_customColor, Color.BLACK)
            typedArray.recycle()
        }
    }
}

Thus, you can use custom attributes defined in XML inside your component.