ios读取文件

//    创建文件管理器
    NSFileManager *fm=[NSFileManager defaultManager];
    //获取路径
    NSArray *paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    
    NSString *documentsDirectory = [paths objectAtIndex:0];
    
    [fm changeCurrentDirectoryPath:documentsDirectory];
    
    //获取文件路劲
    
    NSString* path = [documentsDirectory stringByAppendingPathComponent:@"aaa.txt"];
    
    //查找文件，如果不存在，就创建一个文件
    
    if (![fm fileExistsAtPath:path]) {
        
        [fm createFileAtPath:path contents:nil attributes:nil]; 
    }
    
    NSString *astr = @"aadsdafdsgdfgfd";
    
    [astr writeToFile:path atomically:YES encoding:NSUTF8StringEncoding  error:nil];

 读取文件

//    创建文件管理器
    NSFileManager *fm=[NSFileManager defaultManager];
    //获取路径
    NSArray *paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    
    NSString *documentsDirectory = [paths objectAtIndex:0];
    
    [fm changeCurrentDirectoryPath:[documentsDirectory stringByExpandingTildeInPath]];／／扩张路径
    
    //获取文件路劲
    
    NSString* path = [documentsDirectory stringByAppendingPathComponent:@"aaa.txt"];／／把文件名加在路径后面
    
    NSString *s = [[NSString alloc] initWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
    self.aaa.text=s;

注意：在项目中获取文件路径

NSString  *path=[[NSBundlemainBundle] pathForResource:self.plistofType:@"plist"];

在整个本地计算机上获取文件路径

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