Using Resources in Code

Using resources in code is just a matter of knowing the full resource ID and what type of object your resource has been compiled into. Here is the syntax for referring to a resource:

R.resource_type.resource_name

or

android.R.resource_type.resource_name

Where resource_type is the R subclass that holds a specific type of resource. resource_name is the name attribute for resources defined in XML files, or the file name (without the extension) for resources defined by other file types. Each type of resource will be added to a specific R subclass, depending on the type of resource it is; to learn which R subclass hosts your compiled resource type, consult the Available Resources document. Resources compiled by your own application can be referred to without a package name (simply as R.resource_type.resource_name). Android contains a number of standard resources, such as screen styles and button backgrounds. To refer to these in code, you must qualify them with android, as in android.R.drawable.button_background.

Here are some good and bad examples of using compiled resources in code:

// Load a background for the current screen from a drawable resource.
this.getWindow().setBackgroundDrawableResource(R.drawable.my_background_image);

// WRONG Sending a string resource reference into a 
// method that expects a string.
this.getWindow().setTitle(R.string.main_title);

// RIGHT Need to get the title from the Resources wrapper.
this.getWindow().setTitle(Resources.getText(R.string.main_title));

// Load a custom layout for the current screen.
setContentView(R.layout.main_screen);

// Set a slide in animation for a ViewFlipper object.
mFlipper.setInAnimation(AnimationUtils.loadAnimation(this, 
        R.anim.hyperspace_in));

// Set the text on a TextView object.
TextView msgTextView = (TextView)findViewByID(R.id.msg);
msgTextView.setText(R.string.hello_message);