单击时更改 UIButton 文本

Posted 2023-03-10

【中文标题】单击时更改 UIButton 文本

【英文标题】：Change UIButton text when clicked

【发布时间】：2013-09-03 04:03:05

【问题描述】：

我的程序执行 buttonPressed 方法并执行 if else 语句，但我的按钮上的文本仍然没有改变。有什么我错过的吗？我什至已经在 xib 中对其进行了自定义，但是即使进入其他语句，buttonPlayMusic 的文本仍保持为“播放”。

我想我也连接了按钮。

[viewDidLoad]

  
    self.buttonPlayMusic = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    self.buttonPlayMusic.frame = CGRectMake(((scrollView.frame.size.width - 200) / 2) + cx, 360, 200, 50);
    [self.buttonPlayMusic setTitle:@"Play" forState:UIControlStateNormal];
    [self.buttonPlayMusic addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
    self.toggleButonPlayMusic = YES; //YES to play, NO to stop music
   [scrollView addSubview:self.buttonPlayMusic];

-(IBAction)buttonPressed:(id)sender
NSLog(@"SSS");
if (self.toggleButonPlayMusic == YES) 
    [self.buttonPlayMusic setTitle:@"Stop" forState:UIControlStateNormal];

    self.toggleButonPlayMusic = NO;
     NSLog(@"RRR");
else
    [self.buttonPlayMusic setTitle:@"Play" forState:UIControlStateNormal];
    self.toggleButonPlayMusic = YES;
    NSLog(@"ZZZ");
   

【问题讨论】：

应该没问题。已检查以确保按钮不为零（即，由于某种原因，您实际上没有得到对它的引用。）

self.toggleButonPlayMusic 这是一个布尔变量吗？

@eptdeveloper 是的，它是一个布尔值

【参考方案1】：

不需要额外的布尔变量，只需输入此代码即可正常工作

-(void)viewDidLoad

    [super viewDidLoad];
    //Do any additional setup after loading the view, typically from a nib.
    self.buttonPlayMusic = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    self.buttonPlayMusic.frame = CGRectMake(((scrollView.frame.size.width - 200) / 2) + cx, 360, 200, 50);
    [self.buttonPlayMusic setTitle:@"Play" forState:UIControlStateNormal];
    [self.buttonPlayMusic addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
    [self.buttonPlayMusic setSelected:TRUE]; //YES to play, NO to stop music
    [scrollView addSubview:self.buttonPlayMusic];


-(IBAction)buttonPressed:(id)sender

    if (self.buttonPlayMusic.selected == TRUE) 
    
        [self.buttonPlayMusic setTitle:@"Stop" forState:UIControlStateNormal];            
        [self.buttonPlayMusic setSelected:FALSE];
        NSLog(@"RRR");
     
    else
    
        [self.buttonPlayMusic setTitle:@"Play" forState:UIControlStateNormal];
        [self.buttonPlayMusic setSelected:TRUE];
        NSLog(@"ZZZ");
    

【讨论】：

我不认为布尔值是这里的问题。这可能是不必要的，但不会破坏代码，尤其是当他说 if-else 子句正常工作时。

布尔值不是问题，但是按钮它会自我检查它的状态，所以不需要额外的布尔值来做同样的事情，而你可以用它自己的按钮来检查它。

确实如此，而且它完全是一个更好的实现。

【参考方案2】：

确保您使用 ctrl drag 将引用从文件拖到 viewController 并将其放入 @interface（有时您可能会不小心摆脱这些）。 This post 有一些方法可以确保正确设置连接。

【参考方案3】：

试试这个

-(IBAction)buttonPressed:(id)sender

 UIButton *btn =(UIButton*)sender;
    if (self.buttonPlayMusic.selected == TRUE)
    
        [btn setTitle:@"Stop" forState:UIControlStateNormal];
        [self.buttonPlayMusic setSelected:FALSE];
        NSLog(@"RRR");

    
    else
    
        [btn setTitle:@"Play" forState:UIControlStateNormal];
        [self.buttonPlayMusic setSelected:TRUE];
        NSLog(@"ZZZ");
    

【参考方案4】：

-(IBAction)buttonPressed:(id)sender

    if (self.buttonPlayMusic.titleLabel.text == @"Play")
    
        [self.buttonPlayMusic setTitle:@"Stop" forState:UIControlStateNormal];
        [self.buttonPlayMusic setSelected:FALSE];
        NSLog(@"RRR");
    
    else if (self.buttonPlayMusic.titleLabel.text == @"Stop")
    
        [self.buttonPlayMusic setTitle:@"Play" forState:UIControlStateNormal];
        [self.buttonPlayMusic setSelected:TRUE];
        NSLog(@"ZZZ");