第四节：关于NSUserDefaults介绍

   //将NSUserDefaults的实例化定义成宏

   #define USER_DEFAULT [NSUserDefaults standardUserDefaults]

 /*NSUserDefaults是一个单例，适合存储轻量级的本地数据，一些简单的数据（NSString类型的）例如密码，网址等在整个程序中只有一个实例对象，他可以用于数据的永久保存，一般用来存储简单的信息(支持的数据类有：NSNumber（NSInteger、float、double），NSString，NSDate，NSArray，NSDictionary，BOOL)。*/

   //实例化

   // NSUserDefaults *userdefaults = [NSUserDefaults standardUserDefaults];

   //存数据

   //类型-> NSString

   NSString*userName =@"用户名";

   NSString*userUid =@"用户id";

    [USER_DEFAULTsetObject:userNameforKey:@"name"];

    [USER_DEFAULTsetObject:userUidforKey:@"uid"];

    [USER_DEFAULTsynchronize];//同步存储到磁盘中(可选)

   //取数据

   NSString*_userName = [USER_DEFAULTobjectForKey:@"name"];

   NSString*_userUid = [USER_DEFAULTobjectForKey:@"uid"];

   NSLog(@"_userName = %@,_userUid = %@",_userName,_userUid);

   //清除指定数据

    [USER_DEFAULTremoveObjectForKey:@"name"];

    [USER_DEFAULTremoveObjectForKey:@"uid"];

   //清除所有数据

   NSString*bundle = [[NSBundlemainBundle]bundleIdentifier];

    [USER_DEFAULTremovePersistentDomainForName:bundle];

   //存储时，除NSNumber类型

   //1、存取->NSInteger

   NSIntegerinteger =1;

    [USER_DEFAULTsetInteger:integerforKey:@"integer"];

    [USER_DEFAULTintegerForKey:@"integer"];

   //2、存取->float

   floatflaot =1.0;

    [USER_DEFAULTsetFloat:flaotforKey:@"flaot"];

    [USER_DEFAULTfloatForKey:@"flaot"];

   //3、存取->BOOL

   BOOLisBool =YES;

    [USER_DEFAULTsetBool:isBoolforKey:@"isBool"];

    [USER_DEFAULTboolForKey:@"isBool"];

   //4、存取—>Double

   doubledoulbe =1.2;

    [USER_DEFAULTsetDouble:doulbeforKey:@"doulbe"];

    [USER_DEFAULTdoubleForKey:@"doulbe"];

   /*NSUserDefaults存储的对象全是不可变。要存储一个NSMutableArray对象，必须先创建一个不可变数组（NSArray）再将它存入NSUserDefaults中去。 */

    //7、存取—>NSArray

   NSMutableArray*marry = [NSMutableArrayarrayWithObjects:@"obj_one",@"obj_two",nil];

   NSArray*arry = [NSArrayarrayWithArray:marry];

    [USER_DEFAULTsetObject:arryforKey:@"arry"];

    [NSMutableArrayarrayWithArray:[USER_DEFAULTarrayForKey:@"arry"]];

    //8、存取—>NSDictionary

   NSDictionary*diction = [NSDictionarydictionaryWithObjectsAndKeys:@"Jack",@"name",@"18",@"age",nil];

    [USER_DEFAULTsetObject:dictionforKey:@"diction"];

    [USER_DEFAULTdictionaryForKey:@"diction"];

    //9、存取—>NSData

   UIImage*image = [UIImageimageNamed:@""];

   NSData*imagedata =UIImageJPEGRepresentation(image,1.0);//UIImage-NSData

    [USER_DEFAULTsetObject:imagedataforKey:@"imagedata"];

   NSData*dataimage = [USER_DEFAULTdataForKey:@"imagedata"];

   UIImage*_image = [UIImageimageWithData:dataimage];//NSData-UIImage

   NSLog(@"获取image->%@",_image);