NSDictionary的使用方法及其小例子

NSArray*array1=[NSArrayarrayWithObjects:@"iphone",@"ipod",nil];

NSArray*array2=[NSArrayarrayWithObjects:@"mac",@"imac",@"macpro",nil];

//类方法初始化自动释放

NSDictionary*myDictionary=[NSDictionarydictionaryWithObjectsAndKeys:array1,@"mobile",array2,@"computers",nil];//注意用nil结束

NSLog(@"myDictionary=%@",myDictionary);

intdictSize=[myDictionarycount];

//访问字典中的值

NSArray*mobile=[myDictionaryobjectForKey:@"mobile"];

//从一个对象获取键

NSArray*keys=[myDictionaryallKeysForObject:array1];

//获取字典中所有值得一个数组

NSArray*values=[myDictionaryallValues];

//快速枚举

for(idkeyinmyDictionary)

{

NSLog(@"key:%@,value:%@",key,[myDictionaryobjectForKey:key]);

}

//如果字典只包含属性列表对象(NSData,NSDate,NSNumber,NSString,NSArray或NSDictionary)可以保存到文件中

NSString*filePath=[[[NSBundlemainBundle]resourcePath]stringByAppendingPathComponent:@"dict.txt"];

BOOLsuccess=[myDictionarywriteToFile:filePathatomically:YES];

//用文件填充

NSDictionary*myDict2=[NSDictionarydictionaryWithContentsOfFile:filePath];

//可变字典

NSMutableDictionary*dictMutable=[[NSMutableDictionaryalloc]initWithObjectsAndKeys:array1,@"mobile",array2,@"computer",nil];

NSString*string4=@"stringTV";

//修改对象

[dictMutablesetObject:string4forKey:@"media"];

//删除对象

[dictMutableremoveObjectForKey:@"mobile"];

//删除多个对象

NSArray*keyArray=[NSArrayarrayWithObjects:@"mobile",@"computer",nil];

[dictMutableremoveObjectForKey:keyArray];

//删除所有对象

[dictMutableremoveAllObjects];