iOS基础 - UI布局中所体现的设计思想：复合设计模式

▶ 复合设计模式

1 - 在开发时往往会需要许多零碎的小控件展示在界面上！如果需要一个，就创建一个....那么这样写出的代码太过凌乱，所以采用一种合理的设计模式是很重要。下面代码中就封装了登录页面上所涉及的控件

// - LTView.h

#import <UIKit/UIKit.h>
@interface LTView : UIView

// 方式一
@property(nonatomic,strong)UILabel *titleLabel;
@property(nonatomic,strong)UITextField *textField;

// 方式二
- (id)initWithFrame:(CGRect)frame
              title:(NSString *)title
        placeHolder:(NSString *)placeHolder
    secureTextEntry:(BOOL)secureTextEntry;

// 方式三：彻底封装、隐藏类内部的控件，对外提供一个接口部分(属性)，通过属性赋值，修改控件的内容
// 核心思想: 重写 setter方法，赋值的同时做其他操作
@property(nonatomic,strong)NSString *title;
@property(nonatomic,strong)NSString *placeHolder;
@property(nonatomic,strong)NSString *text;
@property(nonatomic,assign)BOOL secureTextEntry;

@end

// - LTView.m

#import "LTView.h"
@implementation LTView

// 方式一：重写初始化方法，同时自创两个 UI
-(id)initWithFrame:(CGRect)frame{

    self = [super initWithFrame:frame];
    if (self) {

        // titleLabel
        self.titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, frame.size.width / 3.5, frame.size.height)];
        _titleLabel.backgroundColor = [UIColor whiteColor];
        self.titleLabel.text = @"用户名:";
        self.titleLabel.textAlignment = NSTextAlignmentCenter;
        [self addSubview:self.titleLabel];

        // textField
        self.textField = [[UITextField alloc] initWithFrame:CGRectMake(frame.size.width / 3 + .01, 0, frame.size.width - .01 - frame.size.width / 3, frame.size.height)];
        self.textField.borderStyle = UITextBorderStyleRoundedRect;
        self.textField.placeholder = @"请输入用户名";
        self.textField.clearButtonMode = UITextFieldViewModeWhileEditing;
        [self addSubview:self.textField];
    }

    return self;
}

// 方式二：自定义初始化方法，创建对象的同时指定要显示的标题、内容
- (id)initWithFrame:(CGRect)frame
              title:(NSString *)title
        placeHolder:(NSString *)placeHolder
    secureTextEntry:(BOOL)secureTextEntry{

    
    self = [self initWithFrame:frame];

    if (self) {

        self.titleLabel.text = title;
        self.textField.placeholder = placeHolder;
        self.textField.secureTextEntry = secureTextEntry;
    }

    return self;
}

// 方式三:重写 setter
-(void)setTitle:(NSString *)title{

    _title  = title;
    _titleLabel.text = title;
}

-(void)setPlaceHolder:(NSString *)placeHolder{

    _placeHolder = placeHolder;
    _textField.placeholder = placeHolder;
}

- (void)setSecureTextEntry:(BOOL)secureTextEntry{

    _secureTextEntry = secureTextEntry;
    _textField.secureTextEntry = secureTextEntry;
}

- (void)setText:(NSString *)text{

    _text = text;
    _textField.text = text;
}

@end

// - ButtonView.h

#import <UIKit/UIKit.h>

@interface ButtonView : UIView

- (id)initWithFrame:(CGRect)frame
             titles:(NSArray *)titles
           selector:(NSArray *)selectors;

@end

// - ButtonView.m

#import "ButtonView.h"
#define KSpace 10
@implementation ButtonView
- (id)initWithFrame:(CGRect)frame
             titles:(NSArray *)titles
           selector:(NSArray *)selectors{
    
    self = [super initWithFrame:frame];
    if (self) {
        for (int i = 0 ; i < titles.count; i ++) {
            // 创建 Btn
            UIButton *button = [UIButton buttonWithType:UIButtonTypeSystem];
            CGFloat btWidth = (frame.size.width - KSpace) / titles.count - KSpace;
            button.frame = CGRectMake(KSpace * (i + 1) + btWidth * i , 10, btWidth, 30);
            
            NSString *selString = [selectors objectAtIndex:i];
            SEL sel = NSSelectorFromString(selString);
            button.backgroundColor = [UIColor blackColor];
            [button setTitle:[titles objectAtIndex:i] forState:UIControlStateNormal];
        
            [button addTarget:self action:sel forControlEvents:UIControlEventTouchUpInside];
            [self addSubview:button];
        }
    }
    return self;
}

- (void)doRegister{
    NSLog(@"注册");
}
- (void)doLogin{
    NSLog(@"登录");
}
- (void)searchPassword{
    NSLog(@"找回密码");
}

@end

// - LoginView.h

#import <UIKit/UIKit.h>
@class LTView;
@interface LoginView : UIView

@property (nonatomic,strong) LTView *nameView;
@property (nonatomic,strong) LTView *passwordView;


@end

// - LoginView.m

#import "LoginView.h"
#import "ButtonView.h"
#import "LTView.h"

#define KTopMargin 20
#define KLeftMargin 20
#define KSpace 20
#define KLTViewHeight 50
@implementation LoginView

- (id)initWithFrame:(CGRect)frame{

    self = [super initWithFrame:frame];
    if (self) {

        // 用户名：方式一
        self.nameView = [[LTView alloc] initWithFrame:CGRectMake(KLeftMargin, KTopMargin, frame.size.width - KLeftMargin * 2, KLTViewHeight/2.0)];
        [self addSubview:self.nameView];

        // 密码：方式一
        self.passwordView = [[LTView alloc] initWithFrame:CGRectMake(self.nameView.frame.origin.x, self.nameView.frame.origin.y + self.nameView.frame.size.height + KSpace, self.nameView.frame.size.width, self.nameView.frame.size.height)];
        // 方式三
        self.passwordView.title = @"密码:";
        self.passwordView.placeHolder = @"请输入密码";
        self.passwordView.secureTextEntry = YES;
        [self addSubview:self.passwordView];

        // Btn
        NSArray *titlesArray = [NSArray arrayWithObjects:@"注册",@"登录",@"找回密码", nil];
        NSArray *selectorsArray = [NSArray arrayWithObjects:@"doRegister",@"doLogin",@"searchPassword", nil];
        ButtonView *buttonView = [[ButtonView alloc]initWithFrame:CGRectMake(KLeftMargin, self.passwordView.frame.origin.y + KSpace +self.passwordView.frame.size.height, frame.size.width - KLeftMargin * 2, KLTViewHeight) titles:titlesArray selector:selectorsArray];
        buttonView.backgroundColor = [UIColor darkGrayColor];
        [self addSubview:buttonView];
    }

    return self;
}

@end

// - ViewController.m

#import "ViewController.h"
#import "LTView.h"
#import "LoginView.h"
@interface ViewController ()
@property (retain, nonatomic) LoginView * loginView;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

//    // 方式一：输入用户名
//    LTView *lt01 = [[LTView alloc] initWithFrame:CGRectMake(20, 50, self.view.frame.size.width-60, 40)];
//    [lt01 setBackgroundColor:[UIColor blackColor]];
//    [self.view addSubview:lt01];

//    // 方式二：输入用户密码
//    LTView *lt02 = [[LTView alloc] initWithFrame:CGRectMake(20, 120, self.view.frame.size.width-60, 40) title:@"密码:" placeHolder:@"请输入密码" secureTextEntry:YES];
//    lt02.backgroundColor = [UIColor blackColor];
//    [self.view addSubview:lt02];

    
    // 方式三：封装了用户名、用户密码、注册、登录、找回密码 等控件
    self.loginView = [[LoginView alloc] initWithFrame:CGRectMake(10, 50, self.view.frame.size.width-20, 300)];
    self.loginView.backgroundColor = [UIColor brownColor];
    [self.view addSubview:self.loginView];
}

@end 

运行效果