文件路径相关的方法在NSPathUtilities中,主要是操作路径

获得一个路径

 NSString *documents = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]; //获得Document的路径<pre name="code" class="objc">//---~~~/Application/43A22272-F08C-4078-93A9-CAF451BF9814/Documents  //~~~是省略写法

NSArray *components = [documents pathComponents]; //路径的每一个节点的元素<pre name="code" class="objc">     
     "/",
     Users,
     admin,
     Library,
     Developer,
     CoreSimulator,
     Devices,
     "87AB942E-1A11-479C-8010-1F5C36646658",
     data,
     Containers,
     Data,
     Application,
     "43A22272-F08C-4078-93A9-CAF451BF9814",
     Documents

NSString *lastPathComponent = [documents lastPathComponent]; //最后的一个路径节点元素
    //---Documents

NSString *stringByDeletingLastPathComponent = [documents stringByDeletingLastPathComponent];//删除最后一个路径节点元素
    //---~~~/Application/3B14DAE5-8890-42E1-8DC1-664BB35B6333

NSString *stringByAppendingPathComponent = [documents stringByAppendingPathComponent:@"new.txt"]; //加入一个路径元素
    //---~~~/Application/20FED3FC-859A-4C56-945A-FFEEB17A93A2/Documents/new.txt

NSString *pathExtension = [stringByAppendingPathComponent pathExtension];  //文件的后缀名
    //---txt

NSString *stringByDeletingPathExtension = [stringByAppendingPathComponent stringByDeletingPathExtension]; //去掉后缀名
    //---~~~/Application/20FED3FC-859A-4C56-945A-FFEEB17A93A2/Documents/new

NSString *stringByAppendingPathExtension = [stringByDeletingPathExtension stringByAppendingPathExtension:@"txt"]; //加入后缀名
    //---~~~/Application/20FED3FC-859A-4C56-945A-FFEEB17A93A2/Documents/new.txt

NSString *stringByAbbreviatingWithTildeInPath = [documents stringByAbbreviatingWithTildeInPath];  //变成相对路径,前面的都用波浪号省略
    //--- ~/Documents

NSString *stringByExpandingTildeInPath = [stringByAbbreviatingWithTildeInPath stringByExpandingTildeInPath]; //把相对路径变成绝对路径

NSArray *stringsByAppendingPaths = [documents stringsByAppendingPaths:@[@"a",@"b",@"c.txt"]];  //批量加入多个路径,得到一个路径数组
    //---~~~/Application/16474B22-B287-4F7C-9931-E7454B83822E/Documents/a
    //---~~~/Application/16474B22-B287-4F7C-9931-E7454B83822E/Documents/b
    //---~~~/Application/16474B22-B287-4F7C-9931-E7454B83822E/Documents/c.txt