Question

我有一个ViewController，它有六个按钮。每个按钮都有.tag s 1到6，并且都连接到使用IBAction来确定要执行的.tag的同一[self.view viewWithTag: tag]。 4英寸设备上的一切都很棒。

然而，在3.5英寸设备中，我需要重新排列按钮以使其适合。我尝试使用.frame检索按钮并更改检索到的按钮-(void) rearrangeButtons { int space = 7; // space between the first button and the left side of the screen as well as between individual buttons for(int i = 0; i < 6; i++) { // Get the button and remove from superview: UIButton *button = (UIButton *)[self.view viewWithTag: i+1]; [button removeFromSuperview]; // Resize its width and height: UIButton *newButton = [UIButton buttonWithType: UIButtonTypeCustom]; newButton.frame = CGRectMake(space + (i*(button.frame.size.width/2)) + (i*space), 170, button.frame.size.width/2, button.frame.size.height/2); newButton.tag = button.tag; //[newButton addTarget:self action:@selector(highlightButtonWithTag:) forControlEvents:UIControlEventTouchDown]; [newButton targetForAction:@selector(highlightButtonWithTag:) withSender:newButton]; [newButton setBackgroundImage:[UIImage imageNamed:[NSString stringWithFormat:@"icon%i", i+1]] forState:UIControlStateNormal]; [self.view addSubview: newButton]; } }，但这似乎没有做任何事情。因此，我做了以下事情：

- (IBAction) selectIcon:(UIButton *)sender
{
    NSLog(@"called");
    // "Un"highlight previous button
    UIButton *prevButton = (UIButton *)[self.view viewWithTag: self.selectedIcon];
    prevButton.highlighted = NO;

    // Highlight tapped button:
    self.selectedIcon = sender.tag;
    [self performSelector:@selector(highlightButtonWithTag:) withObject:@(self.selectedIcon) afterDelay:0];
}

这将删除按钮并使用新按钮放置它们。安排它们工作正常。但是，我想要被调用的选择器没有被调用，我似乎无法操纵按钮的属性，因为我可以使用我之前做的按钮（尽管这也是纯粹基于他们的标签。

{{1}}

我在这里缺少什么？谢谢！

Answer 1

尝试使用随标记定义的现有按钮实例，而不是创建新的按钮实例。在这种情况下，您不必在superview中添加和删除按钮。只需重复使用它们并在这些按钮上设置框架

-(void) rearrangeButtons
{
    int space  = 7;  // space between the first button and the left side of the screen as well as between individual buttons

    for(int i = 0; i < 6; i++) {
        UIButton *newButton = (UIButton *)[self.view viewWithTag: i+1] ;
        if(newButton == nil) {
            newButton = [UIButton buttonWithType: UIButtonTypeCustom];
            newButton.tag = i+1;
            [self.view addSubview: newButton];
        }
        newButton.frame = CGRectMake(20, i*(i+1) *20, 50, 50);
        [newButton addTarget:self action:@selector(selectIcon:) forControlEvents:UIControlEventTouchDown];
       // [newButton setBackgroundImage:[UIImage imageNamed:[NSString stringWithFormat:@"icon%i", i+1]] forState:UIControlStateNormal];
        [newButton setBackgroundColor:[UIColor redColor]];
    }
}
- (IBAction) selectIcon:(UIButton *)sender
{
    NSLog(@"called");
    // "Un"highlight previous button
    UIButton *prevButton = (UIButton *)[self.view viewWithTag: self.selectedIcon];
    prevButton.highlighted = NO;

    // Highlight tapped button:
    self.selectedIcon = sender.tag;
    [self highlightButtonWithTag:self.selectedIcon];
}

-(void)highlightButtonWithTag:(NSInteger) selectedIcon
{
    NSLog(@"highlightButton at position: %ld", (long)selectedIcon);
}

Answer 2

为什么不使用addTarget：action：forControlEvents：？

[newButton addTarget:self
              action:@selector(highlightButtonWithTag:)
    forControlEvents:UIControlEventTouchUpInside];

为什么我不能与我的按钮互动？

2 个答案: