ios关于数据的存储

本文转载至http://blog.csdn.net/chen505358119/article/details/9278539

            这里我总结了一下数据的存储方式，一是保存在沙盒里创建文件，再把数据写到文件中，二是保存到plist中，三是保存到数据库中.

1.保存到文件中需要借助NSKeyedArchiver和NSKeyedUnArchiver

保存数据：                 NSArray*paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,               NSUserDomainMask,YES);

NSString *path = [pathsobjectAtIndex:0];

NSMutableData *data =[[NSMutableData alloc] init];

NSKeyedArchiver*archiver = [[NSKeyedArchiver alloc]

initForWritingWithMutableData:data];

[archiver encodeObject:_filleText.text forKey:@"ty"];

[archiver finishEncoding];

[data writeToFile:[path stringByAppendingPathComponent:@"test"]

atomically:YES];

[archiver release];

[data release];

获取数据：

NSArray *paths =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);

NSString *path = [pathsobjectAtIndex:0];

NSMutableData *data =[[NSMutableData alloc] initWithContentsOfFile:

[path stringByAppendingPathComponent:@"test"]];

NSKeyedUnarchiver *unarchiver =[[NSKeyedUnarchiver alloc]

initForReadingWithData:data];

NSObject*ret = [[unarchiverdecodeObjectForKey:@"ty"] retain];

[unarchiver finishDecoding];

[unarchiver release];

[data release];

也可以写成这样只不过前一种进行了序列化：

保存：

NSArray *paths =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);

NSString *path = [pathsobjectAtIndex:0];

[NSKeyedArchiver archiveRootObject:_filleText.text toFile:[pathstringByAppendingPathComponent:@"test"]];

获取：

NSArray *paths =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);

NSString *path = [pathsobjectAtIndex:0];

NSString* str=[NSKeyedUnarchiver unarchiveObjectWithFile:[pathstringByAppendingPathComponent:@"test"]];

2.保存到plist文件中

分为两种一种是保存在系统自带的plist中,另一种是保存在自已创建的plist文件中

保存到系统自带的plist

保存:

[[NSUserDefaults standardUserDefaults] setObject:_filleText.textforKey:@"save"];

[[NSUserDefaults standardUserDefaults]synchronize];

获取数据:

NSString*str=[[NSUserDefaults standardUserDefaults] objectForKey:@"save"];

保存到自已创的plist中

保存：

NSMutableDictionary* dict=[NSMutableDictionarydictionaryWithObjectsAndKeys:@"chen",@"sex",@"liang",@"name",nil];

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);

NSString *docPath = [pathsobjectAtIndex:0];

NSString *myFile = [docPath stringByAppendingPathComponent:@"user.plist"];

[dict writeToFile:myFile atomically:YES];

获取数据:

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);

NSString *docPath = [paths objectAtIndex:0];

NSString *myFile = [docPath stringByAppendingPathComponent:@"user.plist"];

NSDictionary* dic = [NSDictionary dictionaryWithContentsOfFile:myFile];

不过我写着写着，觉得第一种和第二种都差不多，基本上都可以归类为保存数据库到文件中，不同的就是保存到plist中可以打开看到里面的数据，第一种看不到，所以更安全些。

3.保存数据到数据库里，一般分为两种一种是ios自带的数据库coredata,另一种是sqllite,我想说的是因为sqllite好多和c关联，如果对c不是很熟悉的话，建议用FMDataBase这个第三方库，它是对sqllite的封装，很好用，对于数据库这块下次再写

有什么问题请大家多指教