The fastest way to get the LayoutInflater

Question

I can get the LayoutInflater with:

inflater = LayoutInflater.from(context);

or

inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

Which way is faster and recommended?

Answer 1

The second version will be (marginally) faster, as the first version involves a method lookup (see code below). For the sake of clarity/maintainability the first version is preferable.

    /**
     * Obtains the LayoutInflater from the given context.
     */
    public static LayoutInflater from(Context context) {
        LayoutInflater LayoutInflater =
                (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        if (LayoutInflater == null) {
            throw new AssertionError("LayoutInflater not found.");
        }
        return LayoutInflater;
    }

Reference: LayoutInflator.java

Answer 2

I do not have the answer to this question but i can suggest a way to find out. You should profile these methods and see for yourself which one is fastest in execution.

You could do this:

long startTime = System.nanoTime();
inflater = LayoutInflater.from(context);
long endTime = System.nanoTime();
long duration = (endTime - startTime);  //divide by 1000000 to get milliseconds.

Run it a few time and write down or save the returned time and then run the other function to see wich one preforms fastest

long startTime = System.nanoTime();
inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
long endTime = System.nanoTime();
long duration = (endTime - startTime);  //divide by 1000000 to get milliseconds.

Now you know how to profile any method you want, to see which one is faster in execution!