工厂模式-简单工厂模式---简介: 工厂模式是创建类型的模式,为什么使用工厂模式?
原因:解除耦合
示例1:
```
//直接实例化对象 控制器和Button 之间建立关系 就有了耦合UIButton *button = [[UIButton alloc] init]; 解决方案: 间接创建 简单工厂模式(静态工厂模式)
ViewFactory.h
#import
#import
@interface ViewFactory : NSObject+ (NSObject *)creatView;
@endViewFactory.m
#import ViewFactory.h
@implamentation ViewFactiory
+(NSObject *)creatView
{return [[UIButton alloc] init];}
@end
```
由于[**示例1**](#markdown-pane)并不完善,相对来说 一个类只能生成一个对象,会造成大量不变,可以查看[**示例2**](#示例2)
示例2:
```
ViewFactory.h
#import
#import
@interface ViewFactory1 : NSObject
+ (NSObject *)creatView:(NSIntger):chose;
@end
ViewFactory.m
#import
@implamentation ViewFactiory1
//根据条件定制对象,有一种增加一种,相对于[示例1]来说 增加了少许的拓展性,这种拓展方法跟[UIButton buttonWithType:UIButtonTypeContactAdd] 实现方式是类似的 buttonWithType: 基于在在父类中做了一系列的判断 并且创建出来
+ (NSObject *)creatView:(NSIntger):chose
{
NSObject *obj = nil;
switch(chose)
{case 1:obj = [[UIButton alloc] init];
break;case 2:
//也可以创建不同的类 比如UIImageView UITextField 等等
obj = [UIButton buttonWithType:UIButtonTypeContactAdd];
break;
default:
obj = [[UIButton alloc] init];
break;
}
return obj;
}@end
```
相对应于[**示例2**](#示例2), 如果添加新的类,就需要不停的更改ViewFactory类文件,这是我们不想看到的,频繁的更改中间文件,所以我们拓展了[**示例3**](#示例3)
示例3:
[ViewFactoryConfing](image/ViewFactoryConfing.xml)
```ViewFactory.h
#import
typedef enum
{ kCreatedControlTypeButton = 1,
kCreatedControlTypeImageView = 2
}kCreatedControlType;
@interface ViewFactory : NSObject
+ (id)getInstance:(NSInteger)chosse;
@end
ViewFactory.m
#import "ViewFactory.h"
#import "ViewXmlParser.h"
@implementation ViewFactory
+ (id)getInstance:(NSInteger)chosse {
ViewXmlParser *parser = [[ViewXmlParser alloc] init];
NSMutableDictionary *dict = [parser parser];
NSString *className = [NSString stringWithFormat:@"%ld",(long)chosse];
return [[[NSClassFromString([dict objectForKey:className]) class] alloc] init];}
@end
ViewXmlParser.h
#import
@interface ViewXmlParser : NSObject
- (NSMutableDictionary *)parser;
@endViewXmlParser.m
#import
"ViewXmlParser.h"
@interface ViewXmlParser ()
@property (nonatomic, strong) NSMutableDictionary *dict;
@property (nonatomic, strong) NSString *currentElementName;
@end
@implementation ViewXmlParser
- (instancetype)init{
self = [super init];
if (self)
{
_dict = [NSMutableDictionary dictionary];
}
return self;}
#pragma mark - Getter
- (NSMutableDictionary *)parser {
NSString *path = [[NSBundle mainBundle] pathForResource:@"ViewFactoryConfing" ofType:@"xml"];
NSURL *url = [[NSURL alloc] initFileURLWithPath:path];
NSXMLParser *parser = [[NSXMLParser alloc] initWithContentsOfURL:url]; parser.delegate = self;
[parser parse];
return _dict;}
#pragma mark - NSXMLParserDelegate
- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary*)attributeDict{
_currentElementName = elementName;
if ([elementName isEqualToString:@"view"]) {
NSString *key = [attributeDict objectForKey:@"key"];
NSString *className = [attributeDict objectForKey:@"className"];
[_dict setObject:className forKey:key];
}
}
```
相对来说[示例3](#示例3)只需要**ViewFacyoryConfing.xml**这个配置文件, 其实苹果的**故事版**和**XIB**也是用工厂模式写的
上诉,说的不对的,请老铁们斧正