UIButton 上不显示标题

Question

我将以下代码用于导航栏中带有标题的自定义后退按钮。但是，标题没有显示，有什么帮助吗？

nb：后退按钮图片是黑色的，和ios默认使用的一样，需要自定义动作处理程序，这就是为什么这样做。

backButton=[UIButton buttonWithType:UIButtonTypeCustom];
[backButton setImage:[UIImage imageNamed:@"backbutton.png"] forState:UIControlStateNormal];
[backButton setImage:[UIImage imageNamed:@"backbutton.png"] forState:UIControlStateSelected];    
[backButton addTarget:self action:@selector(customBack) forControlEvents:UIControlEventTouchUpInside];
[backButton setFrame:CGRectMake(0,0,64,32)];
[backButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
[backButton setTitleColor:[UIColor whiteColor] forState:UIControlStateSelected];
[backButton setTitle:@"Encameo" forState:UIControlStateNormal];
[backButton setTitle:@"Encameo" forState:UIControlStateSelected];

self.navigationItem.leftBarButtonItem=[[UIBarButtonItem alloc] initWithCustomView: backButton];

Answer 1

您在按钮上设置图像而不是这个，您需要设置 UIButton 的 backgroundImage，然后您的标题将被显示。

这样改代码

backButton=[UIButton buttonWithType:UIButtonTypeCustom];
[backButton setBackgroundImage:[UIImage imageNamed:@"backbutton.png"] forState:UIControlStateNormal];
[backButton setBackgroundImage:[UIImage imageNamed:@"backbutton.png"] forState:UIControlStateSelected];    
[backButton addTarget:self action:@selector(customBack) forControlEvents:UIControlEventTouchUpInside];
[backButton setFrame:CGRectMake(0,0,64,32)];
[backButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
[backButton setTitleColor:[UIColor whiteColor] forState:UIControlStateSelected];
[backButton setTitle:@"Encameo" forState:UIControlStateNormal];
[backButton setTitle:@"Encameo" forState:UIControlStateSelected];

self.navigationItem.leftBarButtonItem=[[UIBarButtonItem alloc] initWithCustomView: backButton];