ios – 在文本字段中居中对齐占位符

创建IBOutlet并将其连接到textField.在YourViewController.m中

@interface YourViewController () <UITextFieldDelegate>
@property (weak, nonatomic) IBOutlet UITextField *txt;

在你的viewDidLoad中

self.txt.delegate=self;
self.txt.textAlignment=NSTextAlignmentCenter;

编写此委托方法.每当文本字段中的文本发生更改时,此方法都会调用此方法.

- (BOOL) textField: (UITextField *)theTextField shouldChangeCharactersInRange: (NSRange)range replacementString: (NSString *)string {

    NSRange textFieldRange = NSMakeRange(0, [self.txt.text length]);
    // Check If textField is empty. If empty align your text field to center, so that placeholder text will show center aligned
    if (NSEqualRanges(range, textFieldRange) && [string length] == 0) {
    self.txt.textAlignment=NSTextAlignmentCenter;
    }
    else //else align textfield to left. 
    {
        self.txt.textAlignment=NSTextAlignmentLeft;
    }
    return YES;
}