switch case statement error: case expressions must be constant expression

Question

My switch-case statement works perfectly fine yesterday. But when I run the code earlier this morning eclipse gave me an error underlining the case statements in color red a

Answer 1

I would like to mention that, I came across the same situation when I tried adding a library into my project. All of a sudden all switch statements started to show errors!

Now I tried to remove the library which I added, even then it did not work. how ever "when I cleaned the project" all the errors just went off !

Answer 2

Simply declare your variable to final

Answer 3

Unchecking "Is Library" in the project Properties worked for me.

Answer 4

It was throwing me this error when I using switch in a function with variables declared in my class:

private void ShowCalendar(final Activity context, Point p, int type) 
{
    switch (type) {
        case type_cat:
            break;

        case type_region:
            break;

        case type_city:
            break;

        default:
            //sth
            break;
    }
}

The problem was solved when I declared final to the variables in the start of the class:

final int type_cat=1, type_region=2, type_city=3;

Answer 5

In a regular Android project, constants in the resource R class are declared like this:

public static final int main=0x7f030004;

However, as of ADT 14, in a library project, they will be declared like this:

public static int main=0x7f030004;

In other words, the constants are not final in a library project. Therefore your code would no longer compile.

The solution for this is simple: Convert the switch statement into an if-else statement.

public void onClick(View src)
{
    int id = src.getId();
    if (id == R.id.playbtn){
        checkwificonnection();
    } else if (id == R.id.stopbtn){
        Log.d(TAG, "onClick: stopping srvice");
        Playbutton.setImageResource(R.drawable.playbtn1);
        Playbutton.setVisibility(0); //visible
        Stopbutton.setVisibility(4); //invisible
        stopService(new Intent(RakistaRadio.this,myservice.class));
        clearstatusbar();
        timer.cancel();
        Title.setText(" ");
        Artist.setText(" ");
    } else if (id == R.id.btnmenu){
        openOptionsMenu();
    }
}

http://tools.android.com/tips/non-constant-fields

You can quickly convert a switch statement to an if-else statement using the following:

In Eclipse
Move your cursor to the switch keyword and press Ctrl + 1 then select

Convert 'switch' to 'if-else'.

In Android Studio
Move your cursor to the switch keyword and press Alt + Enter then select

Replace 'switch' with 'if'.

Answer 6

Simple solution for this problem is :

Click on the switch and then press CTL+1, It will change your switch to if-else block statement, and will resolve your problem