Get resources by int number

Issue

I sometimes see this declarations in Android source code:

mContext.getString(2131361954);
Notification n = new Notification(2130837696, "123", System.currentTimeMillis());

// Example code - does not match together

I think the numbers are some resources from the project, right? Why sometimes people work with this numbers instead of using the R class? Is it faster or something else?

And how can I check which resource is assigned to that numbers? Is it possible to get number which is used if I only have the file or is this number random? Maybe with the file name or the MD5 hash of the file or something else?

Solution

There is no performance difference, as all members of the R class are static and final, and are directly swapped in during compile time. This is equivalent to any code that uses R.x.y, so the performance is the same.

I would strongly recommend against using the numbers directly in your project as they may change during the addition, removal and modification of resources.

You can check the resource to which that number corresponds by converting it to hex, opening up the R.java file and searching for that hex number and seeing what it is assigned to.

You can also use getResources().getResourceEntryName(int resid); and pass it the ID at runtime to retrieve the file name.

Answered By - Raghav Sood