我目前无法在UITextField中垂直对齐一个attributionPlaceholder,我不知道为什么.
这就是我在做的事情：
self.addressBar = [[UITextField alloc] initWithFrame: CGRectMake(...)];
self.addressBar.backgroundColor = [UIColor whiteColor];
self.addressBar.attributedPlaceholder = [[NSAttributedString alloc] initWithString:@"Placeholder text"
attributes:@{
NSForegroundColorAttributeName: [UIColor colorWithRed:79/255.0f green:79/255.0f blue:79/255.0f alpha:0.5f],NSFontAttributeName : [UIFont fontWithName:@"Gotham-BookItalic" size:14.0],}
];
self.addressBar.delegate = self;
self.addressBar.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
[self.view addSubview:self.addressBar];
以下是发生的事情：
很明显,这是因为UITextFieldLabel的高度比UItextField本身小10px,但我似乎无法改变它.
这只发生在使用attributionPlaceholder时;默认的占位符属性工作得很好.
有任何想法吗？
解决方法
使用NSParagraphStyle增加最小行高：
NSMutableParagraphStyle *style = [self.addressBar.defaultTextAttributes[NSParagraphStyleAttributeName] mutableCopy];
style.minimumLineHeight = self.addressBar.font.lineHeight - (self.addressBar.font.lineHeight - [UIFont fontWithName:@"Gotham-BookItalic" size:14.0].lineHeight) / 2.0;
self.addressBar.attributedPlaceholder = [[NSAttributedString alloc] initWithString:@"Placeholder text"
attributes:@{
NSForegroundColorAttributeName: [UIColor colorWithRed:79/255.0f green:79/255.0f blue:79/255.0f alpha:0.5f],NSParagraphStyleAttributeName : style
}
];
您还可以覆盖 – (CGRect)placeholderRectForBounds：(CGRect)边界; UITextField子类中的方法.
它很乱,但它的工作原理:)
