Android Studio R.java Page

The R.java file in Android Studio is an automatically generated file that helps to identify all the resources used in an Android project. It contains references to different resources, such as layouts, strings, colors, and images.

Syntax

The syntax for the R.java file is as follows:

public static final class R {
    public static final class id {
        public static final int button_id = 0x7f0e0012;
    }
    public static final class drawable {
        public static final int logo = 0x7f020000;
    }
    public static final class layout {
        public static final int activity_main = 0x7f030000;
    }
    // Other resource types like string, color, etc.
}

Example

An example of the R.java file is:

public static final class R {
    public static final class id {
        public static final int btn_submit = 0x7f080007;
        public static final int txt_name = 0x7f080008;
    }
    public static final class drawable {
        public static final int img_bg = 0x7f020045;
        public static final int img_logo = 0x7f020046;
    }
    public static final class string {
        public static final int app_name = 0x7f050000;
    }
    // Other resource types like layout, color, etc.
}

Output

The output of the R.java file is a list of all the resources used in an Android project. These resources can be accessed using their assigned integer values.

Explanation

The R.java file is a crucial part of an Android project as it helps to identify all the resources used in the project. The different resource types that can be included in the R.java file are id, drawable, layout, string, color, etc.

In the example above, the R.java file contains references to two buttons, a text field, two images, and one string.

Use

The R.java file is used to access different resources in an Android project. The resources can be accessed using their assigned integer values. For example, if we want to access the button with the ID btn_submit, we can use the following code:

Button submitButton = findViewById(R.id.btn_submit);

Here, R.id is used to access the ID of the button and findViewById is used to find the view with the corresponding ID.

Important Points

• The R.java file is automatically generated by Android Studio.
• It contains references to all the resources used in an Android project.
• The different resource types that can be included in the R.java file are id, drawable, layout, string, color, etc.
• The resources can be accessed using their assigned integer values.

Summary

Overall, the R.java file is a crucial part of an Android project as it helps to identify all the resources used in the project. It contains references to different resources and helps in accessing them using their assigned integer values.