iOS学习之基础控件

 1     // 创建UILabel对象
 2     UILabel *userNameLabel = [[UILabel alloc] initWithFrame:CGRectMake(30, 100, 100, 30)];
 3    
 4     // 设置文字
 5     userNameLabel.text = @"用户名";
 6    
 7     // 将UILabel添加到父视图
 8     [self.window addSubview:userNameLabel];
 9    
10     // 释放所有权(MRC模式下)
11     //    [userNameLabel release];
12     // 创建UILabel对象(适配屏幕)
13 
14     UILabel *userNameLabel = [[UILabel alloc] initWithFrame:CGRectMake(20, 200, 80, 40)];
15     UILabel *l1 = [[UILabel alloc] initWithFrame:CGRectMake(CGRectGetMaxX(userNameLabel.frame) + 20,      CGRectGetMinY(userNameLabel.frame), CGRectGetWidth(self.window.frame) - CGRectGetWidth(userNameLabel.frame) - 60, CGRectGetHeight(userNameLabel.frame))];
16     UILabel *l2 = [[UILabel alloc] initWithFrame:CGRectMake(CGRectGetMinX(userNameLabel.frame), CGRectGetMaxY(userNameLabel.frame) + 10, CGRectGetWidth(userNameLabel.frame), CGRectGetHeight(userNameLabel.frame))];
17     UILabel *l3 = [[UILabel alloc] initWithFrame:CGRectMake(CGRectGetMaxX(userNameLabel.frame) + 20, CGRectGetMaxY(userNameLabel.frame) + 10, CGRectGetWidth(self.window.frame) - CGRectGetWidth(userNameLabel.frame) - 60, CGRectGetHeight(userNameLabel.frame))];

   // 设置背景颜色
    userNameLabel.backgroundColor = [UIColor cyanColor];     
      // 设置文本对齐方式
    userNameLabel.textAlignment = NSTextAlignmentRight;
      // 设置文字颜色
    userNameLabel.textColor = [UIColor purpleColor];
      // 设置字体
    userNameLabel.font = [UIFont fontWithName:@"Helvetica-Bold" size:20];
      // 打印所有字体样式
    NSLog(@"%@", [UIFont familyNames]);
     // 显示行数
    userNameLabel.numberOfLines = 3;
      //断行模式（以单词断行）
    userNameLabel.lineBreakMode = NSLineBreakByWordWrapping;
     // 阴影颜色
    userNameLabel.shadowColor = [UIColor blackColor];
     // 阴影大小
    userNameLabel.shadowOffset = CGSizeMake(2, 1);

  // 创建UITextField对象
    UITextField *userNameTextField = [[UITextField alloc] initWithFrame:CGRectMake(100, 100, 190, 30)];
   
    // 设置边框风格
    userNameTextField.borderStyle = UITextBorderStyle RoundedRect;
   
    // 设置占位符
    userNameTextField.placeholder = @"手机号/邮箱";
    // 将UITextField添加到父视图
    [self.window addSubview:userNameTextField];
   
    // 释放所有权（MRC）
    [userNameTextField release];

    // 设置文本内容
    userNameTextField.text = @"用户名:";
    userNameTextField.textColor = [UIColor blackColor];
    // 文本对齐方式
    userNameTextField.textAlignment = NSTextAlignmentLeft;

    // 是否允许编辑
    userNameTextField.enabled = YES;
    // 开始编辑时是否清空输入框
    userNameTextField.clearsOnBeginEditing = YES;
    //是否安全输入
    userNameTextField.secureTextEntry = YES;
    // 弹出键盘的类型
    userNameTextField.keyboardType = UIKeyboardTypeAlphabet;
    // 键盘右下角return按钮类型(枚举值)
    userNameTextField.returnKeyType = UIReturnKeyDefault;

    // 清除按钮模式
    userNameTextField.clearButtonMode = UITextFieldViewModeWhileEditing;
    // 输入框左视图
    UIView *leftView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 30, 30)];
    leftView.backgroundColor = [UIColor yellowColor];
    userNameTextField.leftView = leftView;
    userNameTextField.leftViewMode = UITextFieldViewModeAlways;
    // 输入框右视图
    UIView *rightView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 30, 30)];
    rightView.backgroundColor = [UIColor redColor];
    userNameTextField.rightView = rightView;
    userNameTextField.rightViewMode = UITextFieldViewModeAlways;

    // 1.设置代理
    userNameTextField.delegate = self;
    // 2.遵守协议
    @interface AppDelegate : UIResponder <UIApplicationDelegate,UITextFieldDelegate>
    // 3.实现协议方法

            - (BOOL)textFieldShouldReturn:(UITextField *)textField
    {
        NSLog(@"键盘上回车按键");
        [textField resignFirstResponder];
       
        return YES;
    }
    // 成为第一响应者，运行就进入编辑状态 
    [userNameTextField becomeFirstResponder];

 　　　　  // 1.当textField将要开始编辑的时候告诉委托人

    - (BOOL)textFieldShouldBeginEditing:(UITextField *)textField
    {
        return YES;
    }
         // 2.当textField已经编辑的时候告诉委托人
    - (void)textFieldDidBeginEditing:(UITextField *)textField
    {
    }
         // 3.当textField将要完成编辑的时候告诉委托人
    - (BOOL)textFieldShouldEndEditing:(UITextField *)textField
    {
        return YES;
    }
         // 4.当textField已经完成编辑的时候告诉委托人
    - (void)textFieldDidEndEditing:(UITextField *)textField
    {
       
    }
         // 5.当点击键盘上回车按键时候告诉委托人
    - (BOOL)textFieldShouldReturn:(UITextField *)textField
    {
        return YES;
    }