What are “tag” and “id” on Layouts?

Question

I know how the switch statement works but I don\'t know what this means (R.id.webbutton). Can anyone please explain what it is and also what is TAG? Is there any guide for the

Answer 1

Start with the tutorials. (If you are so absolutely a beginner that you don't have a development environment set up yet, then start with Installing the SDK.)

When you use the console log facility in Android, the first argument to the logging methods is a tag, which can be used to filter logcat output. A typical programming style is:

public class Something { 
    private static final String TAG = "Something";

    public void aMethod() {
        Log.i(TAG, "Entered aMethod");
    }
    . . .
}

That's what TAG is.

Resource IDs are explained in the tutorial. When you define a resource in XML, Android generates a class called R with nested classes for different kinds of resources (R.id, R.string, R.layout, etc.). Each of those nested classes has a constant for each resource of that type. R.id.webbutton might be generated from a layout file that has a button with attribute android:id="@+id/webbutton". This is all explained in the tutorials.