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NSSearchPathForDirectoriesInDomains

2015-01-13 13:31 441 查看
fileManager的基本应用:查看列表

NSArray *NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory directory,NSSearchPathDomainMask domainMask,BOOL expandTilde);

参数

directory 类型有很多,说几个常用的

NSLibraryDirectory,         // various documentation, support, and configuration files, resources (Library)
NSDeveloperDirectory,       // developer resources (Developer) DEPRECATED - there is no one single Developer directory.
NSUserDirectory,            // user home directories (Users)
NSDocumentationDirectory,   // documentation (Documentation)
NSDocumentDirectory,        // documents (Documents)
NSCachesDirectory           // location of discardable cache files (Library/Caches)

domainMask

NSUserDomainMask ,         // user's home directory --- place to install user's personal items (~)
NSLocalDomainMask ,        // local to the current machine --- place to install items available to everyone


NSFileManager *fileManager=[NSFileManager defaultManager];
//NSAllDomainsMask 获取到所有目录结构
NSArray *documentPaths=NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory,NSAllDomainsMask , YES);

for (NSString *str in documentPaths) {
NSLog(@"documentPaths:%@",str);
}

NSString *documentDir=[documentPaths objectAtIndex:0] ;
NSLog(@"documentDir:%@",documentDir);


结果如下:

2013-06-14 16:30:48.253 helloword[1092:c07] documentPaths:/Users/qing/Library/Application Support/iPhone Simulator/6.1/Applications/A3EEDA4B-0F5E-49E5-91D8-FBCCD388B539/Library/Documentation
2013-06-14 16:30:48.258 helloword[1092:c07] documentPaths:/Library/Documentation
2013-06-14 16:30:48.258 helloword[1092:c07] documentPaths:/Network/Library/Documentation
2013-06-14 16:30:48.259 helloword[1092:c07] documentPaths:/System/Library/Documentation

2013-06-14 16:30:48.260 helloword[1092:c07] documentDir:/Users/qing/Library/Application Support/iPhone Simulator/6.1/Applications/A3EEDA4B-0F5E-49E5-91D8-FBCCD388B539/Library/Documentation


NSSearchPathForDirectoriesInDomains:

NSArray *documentPaths=NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory,NSUserDomainMask , YES);
//documentPaths:/Users/qing/Library/Application Support/iPhone Simulator/6.1/Applications/A3EEDA4B-0F5E-49E5-91D8-FBCCD388B539/Library/Documentation

documentPaths=NSSearchPathForDirectoriesInDomains(NSDownloadsDirectory,NSAllDomainsMask , YES);
///Users/qing/Library/Application Support/iPhone Simulator/6.1/Applications/A3EEDA4B-0F5E-49E5-91D8-FBCCD388B539/Downloads


转自 /article/4221551.html

这个主要就是返回一个绝对路径用来存放我们需要储存的文件。

- (NSString *)dataFilePath {

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];

return [documentsDirectory stringByAppendingPathComponent:@"shoppingCar.plist"];
}

NSFileManager* fm=[NSFileManager defaultManager];

if(![fm fileExistsAtPath:[self dataFilePath]]){
//下面是对该文件进行制定路径的保存
[fm createDirectoryAtPath:[self dataFilePath] withIntermediateDirectories:YES attributes:nil error:nil];
//取得一个目录下得所有文件名
NSArray *files = [fm subpathsAtPath: [self dataFilePath] ];
//读取某个文件
NSData *data = [fm contentsAtPath:[self dataFilePath]];
//或者
NSData *data = [NSData dataWithContentOfPath:[self dataFilePath]];
}


转自:http://marshal.easymorse.com/archives/3340

iOS中对文件的操作

因为应用是在沙箱(sandbox)中的,在文件读写权限上受到限制,只能在几个目录下读写文件:

Documents:应用中用户数据可以放在这里,iTunes备份和恢复的时候会包括此目录

tmp:存放临时文件,iTunes不会备份和恢复此目录,此目录下文件可能会在应用退出后删除

Library/Caches: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

在Documents目录下创建文件

代码如下:


NSArray *paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory

, NSUserDomainMask

, YES);

NSLog(@"Get document path: %@",[paths objectAtIndex:0]);

NSString *fileName=[[paths objectAtIndex:0] stringByAppendingPathComponent:@"myFile"];

NSString *content=@"a";

NSData *contentData=[content dataUsingEncoding:NSASCIIStringEncoding];

if ([contentData writeToFile:fileName atomically:YES]) {

NSLog(@">>write ok.");

}



可以通过ssh登录设备看到Documents目录下生成了该文件。

上述是创建ascii编码文本文件,如果要带汉字,比如:


NSString *fileName=[[paths objectAtIndex:0] stringByAppendingPathComponent:@"myFile"];

NSString *content=@"更深夜静人已息";

NSData *contentData=[content dataUsingEncoding:NSUnicodeStringEncoding];

if ([contentData writeToFile:fileName atomically:YES]) {

NSLog(@">>write ok.");

}



如果还用ascii编码,将不会生成文件。这里使用NSUnicodeStringEncoding就可以了。

通过filezilla下载到创建的文件打开,中文没有问题:






在其他目录下创建文件

如果要指定其他文件目录,比如Caches目录,需要更换目录工厂常量,上面代码其他的可不变:


NSArray *paths=NSSearchPathForDirectoriesInDomains(NSCachesDirectory

, NSUserDomainMask

, YES);



使用NSSearchPathForDirectoriesInDomains只能定位Caches目录和Documents目录。

tmp目录,不能按照上面的做法获得目录了,有个函数可以获得应用的根目录:


NSHomeDirectory()



也就是Documents的上级目录,当然也是tmp目录的上级目录。那么文件路径可以这样写:


NSString *fileName=[NSHomeDirectory() stringByAppendingPathComponent:@"tmp/myFile.txt"];



或者,更直接一点,可以用这个函数:


NSTemporaryDirectory()



不过生成的路径将可能是:


…/tmp/-Tmp-/myFile.txt



使用资源文件

在编写应用项目的时候,常常会使用资源文件,比如:





安装到设备上后,是在app目录下的:





以下代码演示如何获取到文件并打印文件内容:


NSString *myFilePath = [[NSBundle mainBundle]

pathForResource:@"f"

ofType:@"txt"];

NSString *myFileContent=[NSString stringWithContentsOfFile:myFilePath encoding:NSUTF8StringEncoding error:nil];

NSLog(@"bundel file path: %@ \nfile content:%@",myFilePath,myFileContent);



代码运行效果:



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