Xcode iOS目标C线程

Question

I want to make an simple ios app.

I want to click on the button and change the backgroundcolor of buttons in a view.

It already is working, but i want to do it asnyc.

For example.

Buttton1 grey Wait a second Button2 grey Wait And so on.

This is the base source:

int i = 1;
UIView *view = viewButtons;
for(UIButton *btnItem in view.subviews)



    NSString *strValue = [@(i) stringValue];
    btnItem.backgroundColor = [UIColor lightGrayColor];
    [btnItem setTitle: strValue forState:UIControlStateNormal];
    i++;

    usleep(1000 * 1000);

Can anyone help me? Thanks!

Answer 1

Take a look at NSTimer . It will allow you to specify an interval and whether you want to repeat the action or not. As Hot Licks mentioned, there are other ways to do it. If you decide to create the thread on your own, eg using GCD , remember that UI updates must be always made on the main thread.

Answer 2

You could use either NSTimer (as previously mentioned) or a dispatch_after() call. If it's a repeating action, use an NSTimer and set it to repeat. If it's a non-repeating action, you could either use an NSTimer set not to repeat, or a dispatch_after() call. Up to you. Definitely do not thread UI code; that has undefined behavior (in other words, it will not work properly).