Cannot make a static reference to the non-static method
There are some good answers already with explanations of why the mixture of the non-static Context
method getText()
can't be used with your static final String
.
A good question to ask is: why do you want to do this? You are attempting to load a String
from your strings
resource, and populate its value into a public static
field. I assume that this is so that some of your other classes can access it? If so, there is no need to do this. Instead pass a Context
into your other classes and call context.getText(R.string.TTT)
from within them.
public class NonActivity {
public static void doStuff(Context context) {
String TTT = context.getText(R.string.TTT);
...
}
}
And to call this from your Activity
:
NonActivity.doStuff(this);
This will allow you to access your String
resource without needing to use a public static
field.
Since getText()
is non-static you cannot call it from a static method.
To understand why, you have to understand the difference between the two.
Instance (non-static) methods work on objects that are of a particular type (the class). These are created with the new like this:
SomeClass myObject = new SomeClass();
To call an instance method, you call it on the instance (myObject
):
myObject.getText(...)
However a static method/field can be called only on the type directly, say like this:
The previous statement is not correct. One can also refer to static fields with an object reference like myObject.staticMethod()
but this is discouraged because it does not make it clear that they are class variables.
... = SomeClass.final
And the two cannot work together as they operate on different data spaces (instance data and class data)
Let me try and explain. Consider this class (psuedocode):
class Test {
string somedata = "99";
string getText() { return somedata; }
static string TTT = "0";
}
Now I have the following use case:
Test item1 = new Test();
item1.somedata = "200";
Test item2 = new Test();
Test.TTT = "1";
What are the values?
Well
in item1 TTT = 1 and somedata = 200
in item2 TTT = 1 and somedata = 99
In other words, TTT
is a datum that is shared by all the instances of the type. So it make no sense to say
class Test {
string somedata = "99";
string getText() { return somedata; }
static string TTT = getText(); // error there is is no somedata at this point
}
So the question is why is TTT static or why is getText() not static?
Remove the static
and it should get past this error - but without understanding what your type does it's only a sticking plaster till the next error. What are the requirements of getText()
that require it to be non-static?