Objective-C 中的反射机制

刚刚发现，OC 中也有类似 Java 中的反射机制：

 

如下代码：

 

UIView *view =[[APLabel alloc] initWithNode:node];

 

可以改写为：

 

Class class= NSClassFromString(@"APLabel");

UIView *view =[[class alloc] initWithNode:node];

 

那么我们现有代码 UIFactory.m 中的 createViewFromNode: 函数只要稍加改造，就可以使代码更简洁，更易扩展。

 

1. 新建一个 plist 文件：ClassRegistry.plist

2. 对 createViewFromNode: 函数重写

- (UIView*)createViewFromNode:(NSDictionary *)node {

               staticNSDictionary *dict = nil;

               if(dict == nil) {

                               NSString*path = [[NSBundle mainBundle] pathForResource:@"ClassRegistry"ofType:@"plist"];

                               dict= [[NSDictionary alloc] initWithContentsOfFile:path];

               }

               NSString*tagName = [[node objectForKey:@"type"] lowercaseString];

               NSString*className = [dict objectForKey:tagName];

               Classclass = NSClassFromString(className);

               return[[[class alloc] initWithNode:node] autorelease];

}