如何创建一个像我在php中但在Objective-C中所做的方法

Question

In PHP I would do something like this:

function changeBgColor($boxColor,$color)
{
    echo '<div id="'. $boxColor .'">'. $color .'</div>';
}

changeBgColor("box1","red");

But I haven't found a way to do this in Objective-C

I want to write out some code in Objective-C and be able to call a method to execute that code.

e.g. execute this code. But I want to change the boxColor and redColor when I call the method

boxColor.backgroundColor = [UIColor redColor]; 

Answer 1

You need to write a method like this:

- (void) changeBackgroundColorOfElement:(NSObject *) element toColour:(UIColor *) color {
    if ([element respondsToSelector:@selector(backgroundColor)]) [element setBackgroundColor:color];
    else if ([element respondsToSelector:@selector(tintColor)]) [element setTintColor:color];
}

that can be called by:

[self changeBackgroundColorOfElement:myLabel toColour:[UIColor blackColor]];

Or you can have the C method which you would call the same way as your PHP code:

void changeBackgroundColorOfElementToColour(NSObject *element, UIColor *color) {
    if ([element respondsToSelector:@selector(backgroundColor)]) [element setBackgroundColor:color];
    else if ([element respondsToSelector:@selector(tintColor)]) [element setTintColor:color];
}

Answer 2

here is a brief explanation on how to create a function in objective C :

- (void) exampleFunction: (int)x y:(int)y
{
do some stuff HERE, changing BG etc
}

you can call this function by :

[self exampleFunction:*TheValueOfX* y:*TheValueOfY*]

this is the basic way of creating a function and using it, there are other more complex things that you might want to read about.