A.从ViewController分离View
之前的代码中，View的数据加载逻辑放在了总的ViewController中，增加了耦合性，应该对控制器ViewController隐藏数据加载到View的细节。
封装View的创建逻辑
封装View的数据加载逻辑到自定义的UIView中
B.思路
使用xib封装自定义view的步骤：
1.新建一个继承UIView的自定义view，这里的名字是“AppView”，用来封装独立控件组
每个AppView封装了如下图的控件组
2.新建一个xib文件来描述控件结构，就是上图的控件组
3.在Controller中使用AppView作为每个独立控件组的类型单位
4.将控件和View “AppView” 进行连线
5.View “AppView” 提供一个模型属性
6.重写模型属性的setter，解析模型数据
7.设置模型数据到控件中
8.自定义View “AppView”的构造方法，屏蔽读取xib文件的细节
其实这就是一种简单的MVC模式
Model: App.h, App.m
View: AppView.h, AppView.m
Controller: ViewController.h, ViewController.m
Controller连接了View和Model，取得数据后加载到Model，然后传给View进行解析并显示
C.实现
1.新建UIView类”AppView"，继承自UIView
new file ==> iOS ==> Source ==> Cocoa Touch Class
创建声明文件”AppView.h”和“AppView.m”
a.
b.
c.
2.设置xib的class (默认是UIView) 为新建的”AppView"
3.在新建的UIView中编写View的数据加载逻辑
（1）在”AppView.h”中创建Model成员
// 在Controller和View之间传输的Model数据 @property(nonatomic, strong) App *appData;
（2）连接控件和”AppView"，创建私有控件成员
（3）在”AppView.m”中解析加载数据
- (void)setAppData:(App *)appData {
_appData = appData;
// 1.设置图片
self.iconView.image = [UIImage imageNamed:appData.icon];
// 2.设置名字
self.nameLabel.text = appData.name;
}
（4）自定义构造方法
AppView.h:
// 自定义将Model数据加载到View的构造方法
- (instancetype) initWithApp:(App *) appData;
// 自定义构造的类方法
+ (instancetype) appViewWithApp:(App *) appData;
// 返回一个不带Model数据的类构造方法
+ (instancetype) appView;
AppView.m:
// 自定义将Model数据加载到View的构造方法
- (instancetype) initWithApp:(App *) appData {
// 1.从NIB取得控件
UINib *nib = [UINib nibWithNibName:@"app" bundle:[NSBundle mainBundle]];
NSArray *viewArray = [nib instantiateWithOwner:nil options:nil];
AppView *appView = [viewArray lastObject];
// 2.加载Model
appView.appData = appData;
return appView;
}
// 自定义构造的类方法
+ (instancetype) appViewWithApp:(App *) appData {
return [[self alloc] initWithApp:appData];
}
// 返回一个不带Model数据的类构造方法
+ (instancetype) appView {
return [self appViewWithApp:nil];
}
（5）在Controller中创建”AppView”并加载数据
// 1.创建View
AppView *appView = [AppView appViewWithApp:appData];
// 2.定义每个app的位置、尺寸
CGFloat appX = marginX + column * (marginX + APP_WIDTH);
CGFloat appY = marginY + row * (marginY + APP_HEIGHT);
appView.frame = CGRectMake(appX, appY, APP_WIDTH, APP_HEIGHT);
// 3.加入此app信息到总view
[self.view addSubview:appView];
主要代码
ViewController.m
#import "ViewController.h"
#import "App.h"
#import "AppView.h"
#define ICON_KEY @"icon"
#define NAME_KEY @"name"
#define APP_WIDTH 85
#define APP_HEIGHT 90
#define MARGIN_HEAD 20
#define ICON_WIDTH 50
#define ICON_HEIGHT 50
#define NAME_WIDTH APP_WIDTH
#define NAME_HEIGHT 20
#define DOWNLOAD_WIDTH (APP_WIDTH - 20)
#define DOWNLOAD_HEIGHT 20
@interface ViewController ()
/** 存放应用信息 */
@property(nonatomic, strong) NSArray *apps; // 应用列表
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[self loadApps];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#pragma mark 取得应用列表
- (NSArray *) apps {
if (nil == _apps) {
// 1.获得plist的全路径
NSString *path = [[NSBundle mainBundle] pathForResource:@"app.plist" ofType:nil];
// 2.加载数据
NSArray *dictArray = [NSArray arrayWithContentsOfFile:path];
// 3.将dictArray里面的所有字典转成模型，放到新数组中
NSMutableArray *appArray = [NSMutableArray array];
for (NSDictionary *dict in dictArray) {
// 3.1创建模型对象
App *app = [App appWithDictionary:dict];
// 3.2 添加到app数组中
[appArray addObject:app];
}
_apps = appArray;
}
return _apps;
}
#pragma mark 加载全部应用列表
- (void) loadApps {
int appColumnCount = [self appColumnCount];
int appRowCount = [self appRowCount];
CGFloat marginX = (self.view.frame.size.width - APP_WIDTH * appColumnCount) / (appColumnCount + 1);
CGFloat marginY = (self.view.frame.size.height - APP_HEIGHT * appRowCount) / (appRowCount + 1) + MARGIN_HEAD;
int column = 0;
int row = 0;
for (int index=0; index<self.apps.count; index++) {
App *appData = self.apps[index];
// 1.创建View
AppView *appView = [AppView appViewWithApp:appData];
// 2.定义每个app的位置、尺寸
CGFloat appX = marginX + column * (marginX + APP_WIDTH);
CGFloat appY = marginY + row * (marginY + APP_HEIGHT);
appView.frame = CGRectMake(appX, appY, APP_WIDTH, APP_HEIGHT);
// 3.加入此app信息到总view
[self.view addSubview:appView];
column++;
if (column == appColumnCount) {
column = 0;
row++;
}
}
}
#pragma mark 计算列数
- (int) appColumnCount {
int count = 0;
count = self.view.frame.size.width / APP_WIDTH;
if ((int)self.view.frame.size.width % (int)APP_WIDTH == 0) {
count--;
}
return count;
}
#pragma mark 计算行数
- (int) appRowCount {
int count = 0;
count = (self.view.frame.size.height - MARGIN_HEAD) / APP_HEIGHT;
if ((int)(self.view.frame.size.height - MARGIN_HEAD) % (int)APP_HEIGHT == 0) {
count--;
}
return count;
}
@end
AppView.m:
#import "AppView.h"
#import "App.h"
// 封装私有属性
@interface AppView()
// 封装View中的控件，只允许自己访问
@property (weak, nonatomic) IBOutlet UIImageView *iconView;
@property (weak, nonatomic) IBOutlet UILabel *nameLabel;
@end
@implementation AppView
- (void)setAppData:(App *)appData {
// 1.赋值Medel成员
_appData = appData;
// 2.设置图片
self.iconView.image = [UIImage imageNamed:appData.icon];
// 3.设置名字
self.nameLabel.text = appData.name;
}
// 自定义将Model数据加载到View的构造方法
- (instancetype) initWithApp:(App *) appData {
// 1.从NIB取得控件
UINib *nib = [UINib nibWithNibName:@"app" bundle:[NSBundle mainBundle]];
NSArray *viewArray = [nib instantiateWithOwner:nil options:nil];
AppView *appView = [viewArray lastObject];
// 2.加载Model
appView.appData = appData;
return appView;
}
// 自定义构造的类方法
+ (instancetype) appViewWithApp:(App *) appData {
return [[self alloc] initWithApp:appData];
}
// 返回一个不带Model数据的类构造方法
+ (instancetype) appView {
return [self appViewWithApp:nil];
}
@end
App.m
#import "App.h"
#define ICON_KEY @"icon"
#define NAME_KEY @"name"
@implementation App
- (instancetype) initWithDictionary:(NSDictionary *) dictionary {
if (self = [super init]) {
self.name = dictionary[NAME_KEY];
self.icon = dictionary[ICON_KEY];
}
return self;
}
+ (instancetype) appWithDictionary:(NSDictionary *) dictionary {
// 使用self代表类名代替真实类名，防止子类调用出错
return [[self alloc] initWithDictionary:dictionary];
}
@end
时间： 2024-08-07 00:14:16