c# - 只有赋值调用 increment decrement 和 new object expressions 可以用作语句

Question

我正在使用 Unity 制作游戏，我不知道为什么会收到此错误。如果你们能帮助我，我将不胜感激。

private enum States
{
    NewGame,
    Cell,
    Sheets, 
    Mirror, 
    Lock, 
    Key, 
    Escape
}

private States my_state;

void state_cell()
{
    text.text = "You are in a jail captured by Indians, you have to escape at all cost. You have to " +
                "aware the Pakistan Army about the evil plans of indians, and you got minimal time left " +
                "\n\n Press S to view the Sheets, press R to return, Press M to get the Mirror,press " +
                "L to view the Lock, and press M to make Key";
    if(Input.GetKeyDown(KeyCode.S))
    {
        (my_state = States.Sheets);
    }
}
void state_sheets()
{
    text.text = "Press S to view the sheets which has info about the security lock, There is some wet " +
                "mud and a metal things lying around see if you can make a key for the Lock " +
                "Also you wanna cut some piece from the Mirror hanging on the wall to find the " +
                "measurements of the Lock";

    if(Input.GetKeyDown(KeyCode.R))
    {
        (my_state = States.Cell);
    }
}

另外我正在使用 monodevelop 版本 4.0.1

Answer 1

你这里的括号是无用的，会导致编译器错误:

(my_state = States.Sheets);

这样做会:

my_state = States.Sheets;

只有在一些情况下才允许使用括号，例如 if () 或 ((CastTo)a) 语句。这不是其中一种情况:不要在赋值周围加上括号。