ios - 如果用户没有足够的硬币，如何阻止操作？

Question

我正在修复一个文字游戏，我制作了一个按钮，允许用户获得小费……但小费需要 10 个硬币。

如果用户没有剩余任何硬币，我如何阻止该操作，同时提醒用户购买硬币？

-(IBAction)btnHint:(id)sender {
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.5];

    CGPoint center = [hints center];
    center.x = 160;
    center.y = 230;
    [hints setCenter:center];

    [UIView commitAnimations];
    hintView.text = @"founded in 1996, and is a sub of telecome";

    coins = coins -10;
}

Answer 1

像这样:

- (IBAction)btnHint:(id)sender {
    if (/* some condition that determines if there are enough coins */) {
        [UIView beginAnimations:nil context:NULL];
        [UIView setAnimationDuration:0.5];

        CGPoint center = [hints center];
        center.x = 160;
        center.y = 230;
        [hints setCenter:center];

        [UIView commitAnimations];
        hintView.text = @"founded in 1996, and is a sub of telecome";

        coins = coins -10;
    } else {
        // show alert
    }
}

顺便说一句 - 你真的应该迁移到现代的基于 block 的 UIView 动画而不是你正在使用的旧方法。