CFB 容器

CFB 容器

Compound File Binary(CFB)是 Outlook .msg 文件使用的容器格式。Aspose.Email FOSS for .NET 提供 CfbReader 用于读取,以及 CfbWriter / CfbDocument 用于直接写入 CFB 容器。


读取 CFB 容器

打开 CFB 文件

using Aspose.Email.Foss.Cfb;

// From file
using var reader = CfbReader.FromFile("sample.msg");

// From stream
using var stream = File.OpenRead("sample.msg");
using var reader2 = CfbReader.FromStream(stream);

// From byte array
var data = File.ReadAllBytes("sample.msg");
using var reader3 = new CfbReader(data);

检查标题和结构

Console.WriteLine($"Version: {reader.MajorVersion}");
Console.WriteLine($"Sector size: {reader.SectorSize}");
Console.WriteLine($"Mini-sector size: {reader.MiniSectorSize}");
Console.WriteLine($"Directory entries: {reader.DirectoryEntryCount}");
Console.WriteLine($"Streams materialized: {reader.MaterializedStreamCount}");
Console.WriteLine($"File size: {reader.FileSize}");

遍历目录树

// Full recursive traversal with depth
foreach (var (depth, entry) in reader.IterTree())
{
    var indent = new string(' ', depth * 2);
    Console.WriteLine($"{indent}{entry.Name} [{entry.ObjectType}]");
}

// Iterate only storages
foreach (var entry in reader.IterStorages())
    Console.WriteLine($"Storage: {entry.Name}");

// Iterate only streams
foreach (var entry in reader.IterStreams())
    Console.WriteLine($"Stream: {entry.Name} ({entry.StreamSize} bytes)");

导航子项并解析路径

// Direct children of the root
foreach (var entry in reader.IterChildren(CfbConstants.RootStreamId))
    Console.WriteLine(entry.Name);

// Resolve a nested path
var target = reader.ResolvePath(new[] { "__substg1.0_0037001F" });
if (target != null)
{
    var streamData = reader.GetStreamData(target.Value);
    Console.WriteLine($"Stream data: {streamData.Length} bytes");
}

按名称查找子项

var child = reader.FindChildByName(CfbConstants.RootStreamId, "__properties_version1.0");
if (child != null)
{
    var bytes = reader.GetStreamData(child.Value);
    Console.WriteLine($"Property stream: {bytes.Length} bytes");
}

编写 CFB 容器

构建 CFB 文档

using Aspose.Email.Foss.Cfb;

var root = new CfbStorage("Root Entry");
root.AddStream(new CfbStream("data.bin", new byte[] { 0x01, 0x02, 0x03 }));

var subStorage = new CfbStorage("SubFolder");
subStorage.AddStream(new CfbStream("nested.txt", System.Text.Encoding.UTF8.GetBytes("hello")));
root.AddStorage(subStorage);

var document = new CfbDocument(root);

序列化为字节或文件

// To byte array
byte[] cfbBytes = CfbWriter.ToBytes(document);

// To file
CfbWriter.WriteFile(document, "output.cfb");

往返验证

// Write and reload
CfbWriter.WriteFile(document, "test.cfb");
using var reloaded = CfbReader.FromFile("test.cfb");

foreach (var entry in reloaded.IterChildren(CfbConstants.RootStreamId))
    Console.WriteLine(entry.Name);

加载现有 CFB 为 CfbDocument

CfbDocument 为现有的 CFB 文件提供内存模型:

var doc = CfbDocument.FromFile("sample.msg");
Console.WriteLine($"Root: {doc.Root.Name}");
Console.WriteLine($"Version: {doc.MajorVersion}.{doc.MinorVersion}");

另请参阅

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