仿制QQ界面

 #pragma mark - @主绘制画面
 - (void)viewDidLoad
 {
     [super viewDidLoad];
     // Do any additional setup after loading the view.

     #pragma mark 1.设置View的背景图片
     UIColor *bgColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"002.jpg"]];
     [self.view setBackgroundColor:bgColor];

     #pragma mark 2.绘制账号
     self.userLabel = [[UILabel alloc]initWithFrame:CGRectMake(20, 120, 50, 40)];
     self.userLabel.text = @"账号";
     [self.userLabel setFont:[UIFont boldSystemFontOfSize:20.0]];
     [self.view addSubview:self.userLabel];
     [self.userLabel release];

     self.userText = [[UITextField alloc]initWithFrame:CGRectMake(self.userLabel.right , self.userLabel.top,self.userLabel.width+170 , self.userLabel.height)];
     self.userText.borderStyle = UITextBorderStyleRoundedRect;
     self.userText.placeholder = @"手机号/会员名/邮箱";
     self.userText.clearButtonMode = UITextFieldViewModeAlways;   // 使输入框后面有个小"x"  用来执行一次性删除
     self.userText.keyboardType = UIKeyboardAppearanceDefault;
     self.userText.keyboardAppearance = UIKeyboardAppearanceAlert;
     self.userText.returnKeyType = UIReturnKeyJoin;
     self.userText.delegate = self;
     [self.view addSubview:self.userText];
     [self.userText release];

     #pragma mark 3.绘制密码
     _pwdLabel = [[UILabel alloc]initWithFrame:CGRectMake(20, 170, 50, 40)];
     _pwdLabel.text = @"密码";
     [_pwdLabel setFont:[UIFont boldSystemFontOfSize:20.0]];
     [self.view addSubview:_pwdLabel];
     [_pwdLabel release];

     _pwdText = [[UITextField alloc]initWithFrame:CGRectMake(_pwdLabel.right, _pwdLabel.top, _pwdLabel.width+170, _pwdLabel.height)];
     _pwdText.borderStyle = UITextBorderStyleRoundedRect;
     _pwdText.placeholder = @"password";
     _pwdText.secureTextEntry = YES;
     _pwdText.clearButtonMode = UITextFieldViewModeAlways;
     _pwdText.keyboardType = UIKeyboardTypeEmailAddress;
     _pwdText.keyboardAppearance = UIKeyboardAppearanceAlert;
     _pwdText.returnKeyType = UIReturnKeyJoin;
     _pwdText.delegate = self;
     [self.view addSubview:_pwdText];
     [_pwdText release];

     #pragma mark 4.绘制是否记住密码控件
     _isLabel = [[UILabel alloc]initWithFrame:CGRectMake(20, 210, 100, 40)];
     _isLabel.text = @"记住密码";
     [_isLabel setFont:[UIFont boldSystemFontOfSize:20.0]];
     [self.view addSubview:_isLabel];
     [_isLabel release];

     _isISwitch = [[UISwitch alloc]initWithFrame:CGRectMake(230, 215, 40, _isLabel.height)];
     [_isISwitch addTarget:self action:@selector(openOrClosed:) forControlEvents:UIControlEventValueChanged];
     [self.view addSubview:_isISwitch];

     #pragma mark 5.绘制登录按钮
     _login = [UIButton buttonWithType:UIButtonTypeSystem];
     _login.frame = CGRectMake(40, 250, 240, 40);
     [_login.titleLabel setFont:[UIFont boldSystemFontOfSize:30.0]];    // 设置字体大小
     _login.tintColor = [UIColor blackColor];
     [_login setBackgroundImage:[UIImage imageNamed:@"login1.png"] forState:UIControlStateNormal];  // 设置按钮的背景图片
     [_login setTitle:@"登录" forState:UIControlStateNormal];
     [_login addTarget:self action:@selector(loginView:) forControlEvents:UIControlEventTouchUpInside];

     [self.view addSubview:_login];

 }

 #pragma mark - @响应是否记住密码开关
 - (IBAction)openOrClosed:(id)sender{

     UISwitch * switchButton = (UISwitch *)sender;
     if ([switchButton isOn]) {
         NSLog(@"YES");
     } else {
         NSLog(@"NO");
     }

 }


 #pragma mark - @响应点击登录按钮
 - (IBAction)loginView:(id)sender{

     HMTMainViewController * mainVC = [[HMTMainViewController alloc]init];
     UINavigationController * mainNC = [[UINavigationController alloc]initWithRootViewController:mainVC];
     // 模态视图控制器呈现出来时候的视觉效果
     mainVC.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
     // 模态视图控制器呈现方式,默认全屏
     mainVC.modalPresentationStyle = UIModalPresentationFullScreen;

     NSString * userString = self.userText.text;
     NSString * pwdString  = self.pwdText.text;
     if ([userString isEqualToString:@"23423423424"] && [pwdString isEqualToString:@"hE2342340"] ) {

         [self presentViewController:mainNC animated:YES completion:^{
             NSLog(@"登陆成功");
         }];

     } else {
         NSLog(@"用户名或者密码错误");
     }


     [mainNC release];
     [mainVC release];

     #pragma mark 第3种方式收回键盘
     // 当前视图结束编辑
     [self.view endEditing:YES];
 }

 #pragma mark - @3种方法来收回弹出来的键盘
 #pragma mark  第1种方式来收回键盘 -------> 通过UITextField本身的协议来实现
 - (BOOL)textFieldShouldReturn:(UITextField *)textField
 {
     // 放弃第一响应者
     [textField resignFirstResponder];
     return YES;
 }

 #pragma mark  第2种方式来收回键盘 -------> 通过重写UIResponder的方法
 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{

     // selfself.view.subviews 返回的是加载在View视图上的所有视图的数组
     [self.view.subviews enumerateObjectsUsingBlock:^(UIView* obj, NSUInteger idx, BOOLBOOL *stop) {
         if ([obj isKindOfClass:[UITextField class]]) {
             [obj resignFirstResponder];
         }
     }];

 }