Question

我正在创建一个应用，我在屏幕上有三个按钮。必须始终选择其中一个按钮。当应用程序加载时，第一个按钮被设置为选中，并执行其操作。当用户按下另一个按钮时，取消选择当前按钮并选择新按钮。

我对Objective-C有点新鲜。这就是我提出的，但没有一个我期待的工作。我在标题中设置了按钮插座。



    - (IBAction)buttonSelector:(id)sender
    {
        firstButton.selected = YES;
        secondButton.selected = NO;
        thirdButton.selected = NO;

        if (firstButton.selected = YES)
        {
            [firstbutton setBackgroundImage:[UIImage imageNamed:"selected.png"]];
            secondButton.selected = NO;
            [secondButton setBackgroundImage:[UIImage imageNamed:"un_selected.png"]];
            thirdButton.selected = YES;
            [thirdButton setBackgroundImage:[UIImage imageNamed:"un_selected.png"]];
        } else if (secondButton.selected = YES)
        {
            [secondButton setBackgroundImage:[UIImage imageNamed:"selected.png"]];
            firstButton.selected = NO;
            [firstButton setBackgroundImage:[UIImage imageNamed:"un_selected.png"]];
            thirdButton.selected = NO;
            [firstButton setBackgroundImage:[UIImage imageNamed:"un_selected.png"]];
        } else if (thirdButton.selected = YES)
        {
            [thirdButton setBackgroundImage:[UIImage imageNamed:"selected.png"]];
            firstButton.selected = NO;
            [firstButton setBackgroundImage:[UIImage imageNamed:"un_selected.png"]];
            secondButton.selected = NO;
            [secondButton setBackgroundImage:[UIImage imageNamed:"un_selected.png"]];
        } else {
            [sender setBackgroundImage:[UIImage imageNamed:"un_selected.png"]];
        }

    }

修改1：

我尝试了UISegmentedControl，但似乎无法为我正在寻找的内容进行足够的自定义。理想情况下，按钮将更多沿着这些线： http://i.stack.imgur.com/LPwoR.jpg

按钮将有一个将改变的背景图像

Answer 1

您应该使用UISegmentControl。这是您正在寻找的确切功能。这是apple documentation on this

Here is a tutorial from Ray wenderlich关于如何自定义包含UISegmentControl。

的UI元素

例如： -

NSArray *itemArray = [NSArray arrayWithObjects: @"One", @"Two", @"Three", nil];
UISegmentedControl *segmentedControl = [[UISegmentedControl alloc] initWithItems:itemArray];
segmentedControl.frame = CGRectMake(35, 200, 250, 50);
segmentedControl.segmentedControlStyle = UISegmentedControlStylePlain;

Answer 2

只需使用for循环执行此任务，首先只需将图像设置为所有按钮，然后更改所选图像的图像。

允许选择3个UIButtons中的1个

2 个答案: