判短文件是否存在

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

    NSString *ducumentsDirectory = [paths objectAtIndex:0];

    NSFileManager *fm = [NSFileManager defaultManager];

    NSString *FilePath = [NSString stringWithFormat:@"%@%@",ducumentsDirectory,@"/LifeAccount.sqlite"];

    if ([fm fileExistsAtPath:FilePath]) {

        

        return FilePath;

    }