UIButton *rightBtn =[[UIButton alloc] initWithFrame:CGRectMake(CGRectGetMaxX(textField.frame)+20, CGRectGetMinY(textField.frame), 40, 30)];

[rightBtn setTitleColor:__kColorGray forState:UIControlStateNormal];

[rightBtn addTarget:self action:@selector(buttonClick:) forControlEvents:UIControlEventTouchUpInside];

[rightBtn setTitle:@"取消" forState:UIControlStateNormal];

self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:rightBtn];