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:];

    [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];