沙盒

1、沙盒

• 程序只能访问自己的沙盒
• NSHomeDirectory() 访问沙盒路径
• 沙盒下有三个目录：Documents、Library、tmp
• 图

屏幕快照 2016-03-12 下午4.48.19.png

Documents：
- 1)一般用存在程序中创建的文件
- 2)程序中浏览到的文件数据保存在该目录下
- 3)iTunes备份和恢复的时候会包括此目录

//Documents路径
NSString *address = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];

Library:
- 1)存储应用的默认设置及状态信息

Library/Caches：
- 1)存放缓存文件，iTunes不会备份此目录，此目录下文件不会在应用退出删除

Library/Preferences:
- 1)目录包含应用程序的偏好设置文件。您不应该直接创建偏好设置文件，而是应该使用NSUserDefaults

//Library路径
NSString * Libraryaddress = [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES) lastObject];

//Caches路径
NSString *address = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) firstObject];
//
[Libraryaddress stringByAppendingFormat:@"/Caches"]

//Preferences路径
[Libraryaddress stringByAppendingFormat:@"/Preference"]

tmp：
- 1)提供一个即时创建临时文件的地方

//tmp路径
NSString *string = NSHomeDirectory();
NSString *tmp = [string stringByAppendingFormat:@"/tmp"];
//
NSString *string = NSTemporaryDirectory();

• 注意

iTunes在与iPhone同步时，备份所有的Documents和Library文件。
iPhone在重启时，会丢弃所有的tmp文件。

• 写入沙盒

NSString *string = NSTemporaryDirectory();

//NSString
NSString *stringH = @"HHHHHHHHHHHHH";
[stringH writeToFile:[string stringByAppendingString:@"HH.text"] atomically:YES encoding:NSUTF8StringEncoding error:nil];

// NSArray/NSDictionary/NSData
NSArray *arr = [NSArray arrayWithObjects:@"1",@"2",@"3", nil];
[arr writeToFile:[string stringByAppendingString:@"arr.text"] atomically:YES];

• 删除沙盒文件

NSString *string = NSTemporaryDirectory();
NSFileManager *manager = [NSFileManager defaultManager];
[manager removeItemAtPath:[string stringByAppendingString:@"arr.text"] error:nil];

• 判断沙盒中是否有此文件

BOOL isExsit = [manager fileExistsAtPath:[string stringByAppendingString:@"HH.text"]];

    NSFileManager *manager = [NSFileManager defaultManager];
    NSString *imgHPath = [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) firstObject] stringByAppendingPathComponent:@"/imgH"];
    // 创建一个文件夹
    if (![manager isExecutableFileAtPath:imgHPath]) {
        [manager createDirectoryAtPath:imgHPath withIntermediateDirectories:YES attributes:nil error:nil];
    }
    
    //向imgH文件中添加图片
    NSURL *url = [NSURL URLWithString:imgString];
    NSString *pathString = [NSString stringWithFormat:@"/%@", [imgString substringFromIndex:(imgString.length - 7)]];
    NSString *cachePath = [imgHPath stringByAppendingPathComponent:pathString];
    NSLog(@"%@", cachePath);

    // 删除imgH文件
    NSString *imgHPath = [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) firstObject] stringByAppendingPathComponent:@"/imgH"];
    NSFileManager *manager = [NSFileManager defaultManager];
    if ([manager isExecutableFileAtPath:imgHPath]) {        
        [manager removeItemAtPath:imgHPath error:nil];
    }
    NSLog(@"%@", NSHomeDirectory());

转自：http://my.oschina.net/joanfen/blog/151145