如何在Objective-C中设置文本字段的委托？

// 导入UIKit框架
#import <UIKit/UIKit.h>

// 创建一个遵循UITextFieldDelegate协议的类
@interface MyViewController : UIViewController <UITextFieldDelegate>

@property (strong, nonatomic) UITextField *textField;

@end

@implementation MyViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    // 创建一个UITextField对象
    self.textField = [[UITextField alloc] initWithFrame:CGRectMake(50, 100, 200, 40)];
    self.textField.borderStyle = UITextBorderStyleRoundedRect;
    
    // 将代理设置为当前类的实例
    self.textField.delegate = self;
    
    // 将文本字段添加到视图中
    [self.view addSubview:self.textField];
}

// 实现UITextFieldDelegate协议的方法
- (void)textFieldDidBeginEditing:(UITextField *)textField {
    NSLog(@"开始编辑");
}

- (void)textFieldDidEndEditing:(UITextField *)textField {
    NSLog(@"结束编辑");
}

- (void)textFieldDidChangeSelection:(UITextField *)textField {
    NSLog(@"文本改变");
}

@end