UITextField的创建与方法的重写

• (void)viewDidLoad {
  [super viewDidLoad];
  // Do any additional setup after loading the view, typically from a nib.

  //初始化textfield并设置位置及大小
  UITextField * text = [[UITextField alloc]initWithFrame:CGRectMake(20, 20, 130, 30)];

  //设置输入框的背景颜色
  text.backgroundColor = [UIColor redColor];

  // 中点的x
  CGFloat centerX = self.view.frame.size.width * 0.5;
  CGFloat centerY = self.view.frame.size.height * 0.5;
  text.center = CGPointMake(centerX, centerY);

  // 设置字体
  text.font = [UIFont systemFontOfSize:30];

  text.delegate = self;

  //把textfield添加到视图上
  [self.view addSubview:text];

}

//开始编辑时的方法
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField{
NSLog(@”a”);

//编写时背景颜色修改成绿色textField.backgroundColor = [UIColor greenColor];return YES;

}

• (void)touchesBegan:(NSSet