Question

我找到了这段代码（用appdelegate编写的应用程序）。我想要的只是让它支持另一个视图（我创建它）。

代码：

- (IBAction)swap
{
    NSArray *subs = [window subviews];
    [[subs objectAtIndex:0] removeFromSuperview];
    if([subs objectAtIndex:0] == view2){
        [window addSubview:view1];
    } else if([subs objectAtIndex:0] == view1){
        [window addSubview:view2];
    }
}

Answer 1

假设视图1,2和3是唯一的视图 -

- (IBAction)swap
{
    [window sendSubviewToBack:[[window subviews] lastObject]];
}

或者，改变方向

- (IBAction)swap
{
    [window bringSubviewToFront:[[window subviews] objectAtIndex:0]];
}

Answer 2

- (IBAction)swap
{
    NSArray *subs = [window subviews];
    UIView *currentView = (UIView *)[subs objectAtIndex:0];
    [currentView removeFromSuperview];
    if(currentView == view1){
        [window addSubview:view2];
    } else if(currentView == view2){
        [window addSubview:view3];
    } else 
        [window addSubview:view1];
    }
}

Answer 3

如果你不想用IF ELSE折磨你的自我，你可以使用一系列视图并迭代它们。

NSArray *myViews = [NSArray arrayWithObjects:view1, view2, view3, nil];

NSInteger nextIndex = [myViews indexOfObject:[[window subviews] objectAtIndex:0]] + 1;

nextIndex = (nextIndex % [myViews count]); // to loop around if reached the end
[window addSubview:[myViews objectAtIndex:nextIndex]];

您可以对视图数组做一些聪明的事情，这样您就不会在每次交换时重新创建它。

修改此代码以支持其他视图

3 个答案: