iOS开发知识体系——File Manager

一、获取文件属性的方法：
    1> NSDictionary *folderAttr = [[NSFileManager defaultManager] attributesOfFileSystemForPath:NSHomeDirectory() error:nil];
    获取文件夹大小：[folderAttr objectForKey:NSFileSystemSize];
    剩余空间：[folderAttr objectForKey:NSFileSystemFreeSize];
    代替方法：fileSystemAttributesAtPath
    2> NSDictionary * fileAttributes = [FileDefaultManager attributesOfItemAtPath:filePath error:&error];
    获取文件大小：unsigned long long length = [fileAttributes fileSize];
    代替方法：fileAttributesAtPath:traverseLink

二、常用方法整理

//返回文件大小(字节byte)
+ (unsigned long long)getFileSize:(NSString *)filePath{
    if (![FileDefaultManager fileExistsAtPath:filePath]) {MyNSLog(@"要计算大小的文件不存在!!!filePath=%@", filePath);return 0;}
    NSError *error=nil;//局部变量必须赋值，并不是默认的nil
    NSDictionary * fileAttributes = [FileDefaultManager attributesOfItemAtPath:filePath error:&error];
    if (fileAttributes == nil || error!=nil) {MyNSLog(@"文件大小计算出错！err=%@",error.localizedDescription);return 0;}    
    return [fileAttributes fileSize];
}
//拷贝文件
+ (BOOL)fileCopy:(NSString *)sName TargetName:(NSString *)tName{
    NSError *error=nil;
    BOOL isSucces=NO;
    if (![FileDefaultManager fileExistsAtPath:sName]) {
        MyNSLog(@"要拷贝的源文件不存在!!!sName=%@", sName);
        return NO;
    }
    if ([FileDefaultManager fileExistsAtPath:tName]) {
        MyNSLog(@"要拷贝的目标文件已经存在!!!马上删除之...%@", tName);
        isSucces=[self fileDelete:tName];//如果不删除，后面的拷贝要失败
    }
    
    isSucces=[FileDefaultManager copyItemAtPath:sName toPath:tName error:&error];//调用拷贝方法
    if (error != nil) {
        MyNSLog(@"拷贝文件出错:%@", [error localizedDescription]);
    }else{
        MyNSLog(@"拷贝文件成功！");
    }
    return isSucces; 
}
//删除文件和文件夹
+ (BOOL)fileDelete:(NSString *)filePath{
    NSError *error=nil;
    BOOL isSucces=NO;
    if (![FileDefaultManager fileExistsAtPath:filePath]) {
        MyNSLog(@"要删除的地址不存在!!!filePath=%@", filePath);
        return NO;
    }
    
    isSucces=[FileDefaultManager removeItemAtPath:filePath error:&error];//调用删除方法
    if (error != nil) {
        MyNSLog(@"删除出错:%@", [error localizedDescription]);
    }else{
        MyNSLog(@"删除成功！");
    }
    return isSucces; 
}

//返回目录下所有的文件名(不包括路径)数组
+ (NSArray *)allFilesInFolderPath:(NSString *)folderPath{
    return [FileDefaultManager contentsOfDirectoryAtPath:folderPath error:nil];
}
//返回目录下所有文件的名称(不包括路径)和大小
+ (NSMutableArray *)allFilesAttributeInFolderPath:(NSString *)folderPath{
    NSArray *filesName = [FileDefaultManager contentsOfDirectoryAtPath:folderPath error:nil];
    NSMutableArray *fileAttributes = [NSMutableArray new];
    for (NSString *fileName in filesName) {
        NSString *filePath = [folderPath stringByAppendingPathComponent:fileName];//完整路径
        BOOL isDir;//判断该路径是不是文件夹
        BOOL isExists = [FileDefaultManager fileExistsAtPath:filePath isDirectory:&isDir];
        if (![fileName.lowercaseString hasSuffix:@"ds_store"] && isExists && !isDir) {//过滤文件夹和索引文件.DS_Store
            NSError *error = nil;
            NSDictionary *attributes = [FileDefaultManager attributesOfItemAtPath:filePath error:&error];
            NSDictionary *dicTemp = [[NSDictionary alloc] initWithObjectsAndKeys:
                                     fileName,@"filename",
                                     [NSString stringWithFormat:@"%llu",[attributes fileSize]],@"filesize",
                                     nil];
            [fileAttributes addObject:dicTemp];
            dicTemp = nil;
        }
    }
    return fileAttributes;
}
//删除目录下所有文件和文件夹
+ (void)filesDelete:(NSString *)folderPath{
    NSArray *files = [self allFilesInFolderPath:folderPath];
    MyNSLog(@"files count=%d", [files count]);
    for (NSString *file in files) {
        NSString *filePath = [folderPath stringByAppendingPathComponent:file];//转换成url
        BOOL isDir;//判断该路径是不是文件夹
        BOOL isExists = [FileDefaultManager fileExistsAtPath:filePath isDirectory:&isDir];//返回文件或文件夹是否存在
        if (isExists) {
            [self fileDelete:filePath];
        }
    }
}
//创建文件夹
+ (BOOL)folderCreate:(NSString *)folderPath{
    NSError *error = nil;
    BOOL isSucces=NO;
    BOOL isDir;//判断该路径是不是文件夹
    BOOL isExists = [FileDefaultManager fileExistsAtPath:folderPath isDirectory:&isDir];//返回文件或文件夹是否存在
    if (isExists && isDir) {
        MyNSLog(@"%@文件夹已经存在!不需要创建!",folderPath);
        return YES;
    }
    
    MyNSLog(@"开始创建文件夹%@",folderPath);
    isSucces=[FileDefaultManager createDirectoryAtPath:folderPath withIntermediateDirectories:YES attributes:nil error:&error];
    if (error != nil) {
        MyNSLog(@"创建出错:%@", [error localizedDescription]);
    }else{
        MyNSLog(@"创建成功！");
    }
    return isSucces;
}