UE4 热更新原理

最新推荐文章于 2025-11-15 17:57:55 发布

原创最新推荐文章于 2025-11-15 17:57:55 发布 · 1.2w 阅读

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CC 4.0 BY-SA版权

本文介绍UE4热更新中Pak包的生成方法及基于版本号的增量更新流程，涵盖自定义工具实现及蓝图调用HTTP下载。

本文参考https://blog.ch-wind.com/ue4-patch-release-dlc/

UE4的热更新，目的就是更新Pak包，生成Pak包的方法网上很多，根据需求看使用UE4自带的（搜索DLC），还是自己根据自己的规则打pak都是可以的（搜索UnrealPak.exe）

UE4生成Pak的规则是（基于UE4提供的Launch），先生成游戏主体，游戏主体会要填版本号，后面不管是DLC还是Patch都是基于这个游戏主体生成的，后面的不管项目改动什么，在生成DLC或者Patch的时候，都有一个基于版本号，这个版本号就是主体的版本号，都是基于主体做的增量更新，生成游戏主体在没有指定保存路径的情况下，是生成在项目根目录下的Release文件夹下面

下载pak包在蓝图里面提供的有Request Content 和 Start Install就可以完成pak的下载，这个下载只能一次下载一个pak，所有还是要有一个更新的文件列表，我自己简单写了一个Windows Application的工具后面添上源码，让人奇怪的是 UE4蓝图里面并没有提供Http的下载接口，所有自己也写了一个后面添上

Windows Application代码（生成Version的）

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using Newtonsoft.Json;
using System.IO;

namespace MakeVersion
{
public partial class Form1 : Form
{
private string mainfestPath = "";
private string versionPath = "";
private string version = "";
private List<string> mainfestList = new List<string>();
public Form1()
{
InitializeComponent();
}

//选择mainfest文件，并加入List
private void button1_Click(object sender, EventArgs e)
{
FolderBrowserDialog dialog = new FolderBrowserDialog();
dialog.Description = "选择MainfestDir目录";
if (dialog.ShowDialog() == DialogResult.OK)
{
if (string.IsNullOrEmpty(dialog.SelectedPath))
{
MessageBox.Show(this, "选择文件夹不能为空");
return;
}

MainfestPathText.Text = mainfestPath = dialog.SelectedPath;
DirectoryInfo folder = new DirectoryInfo(dialog.SelectedPath);
mainfestList.Clear();
foreach (FileInfo file in folder.GetFiles())
{
if (!file.Name.Contains(".manifest"))
continue;

mainfestList.Add(file.Name);
}
}
}

//选择保存version的目录
private void button2_Click(object sender, EventArgs e)
{
FolderBrowserDialog dialog = new FolderBrowserDialog();
dialog.Description = "选择保存version的目录";
if (dialog.ShowDialog() == DialogResult.OK)
{
if (string.IsNullOrEmpty(dialog.SelectedPath))
{
MessageBox.Show(this, "请选择文件夹");
return;
}

SavePathText.Text = versionPath = dialog.SelectedPath;
}
}

private void button3_Click(object sender, EventArgs e)
{
if (mainfestList.Count < 1 || string.IsNullOrEmpty(mainfestPath) || string.IsNullOrEmpty(versionPath))
{
MessageBox.Show(this, "前面的路径选择操作违法或没有要生成的mainfest文件");
return;
}

if (string.IsNullOrEmpty(VersionText.Text))
{
MessageBox.Show(this, "请输入生成的版本号");
return;

}

StringBuilder sb = new StringBuilder();
StringWriter sw = new StringWriter(sb);
JsonTextWriter jsonWrite = new JsonTextWriter(sw);
jsonWrite.Formatting = Formatting.Indented;

jsonWrite.WriteStartObject();
jsonWrite.WritePropertyName("ClientVersion:");
jsonWrite.WriteValue(VersionText.Text);

jsonWrite.WritePropertyName("Files");
jsonWrite.WriteStartArray();

string readTxt = string.Empty;
string readPath = string.Empty;
string value = string.Empty;
Newtonsoft.Json.Linq.JObject jo = null;
for (int i = 0; i < mainfestList.Count; i++)
{
readPath = mainfestPath + "\\" + mainfestList[i];
if (!File.Exists(readPath)) continue;
readTxt = File.ReadAllText(readPath, Encoding.ASCII);
if (string.IsNullOrEmpty(readTxt)) continue;

jo = (Newtonsoft.Json.Linq.JObject)JsonConvert.DeserializeObject(readTxt);
jsonWrite.WriteStartObject();
jsonWrite.WritePropertyName("FileName");
jsonWrite.WriteValue(jo["FileManifestList"][0]["Filename"].ToString());
jsonWrite.WritePropertyName("FileHash");
jsonWrite.WriteValue(jo["FileManifestList"][0]["FileHash"].ToString());
jsonWrite.WriteEndObject();
}

MessageBox.Show("生成完毕");
jsonWrite.WriteEndArray();
jsonWrite.WriteEndObject();

File.WriteAllText(versionPath + "/Version.txt", sb.ToString());
}
}
}

Windows Appication（生成Pak的，要在项目的build.cs文件里面添加 Http 和 Json）

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace UnrealPakTool
{
public partial class Form1 : Form
{
private string m_UnrealToolPath = "";
private string m_InputFolderPath = "";
private string m_OutPutPakPath = "";
private List<string> m_NeedMakePakList = new List<string>();
public Form1()
{
InitializeComponent();
}

private void label1_Click(object sender, EventArgs e)
{

}
//UnrealPak所在的文件夹路径
private void button1_Click(object sender, EventArgs e)
{
FolderBrowserDialog dialog = new FolderBrowserDialog();
dialog.Description = "请选择UnrealPak所在的文件目录";
if (dialog.ShowDialog() == DialogResult.OK)
{
if (string.IsNullOrEmpty(dialog.SelectedPath))
{
MessageBox.Show(this, "选择文件夹不能为空");
return;
}

m_UnrealToolPath = dialog.SelectedPath;
textBox1.Text = dialog.SelectedPath;
}
}
//需要打包的文件夹路径
private void button2_Click(object sender, EventArgs e)
{
FolderBrowserDialog dialog = new FolderBrowserDialog();

dialog.Description = "请选择uasset所在的文件夹";
if (dialog.ShowDialog() == DialogResult.OK)
{
if (string.IsNullOrEmpty(dialog.SelectedPath))
{
MessageBox.Show(this, "选择文件夹不能为空");
return;
}

m_InputFolderPath = dialog.SelectedPath;
textBox2.Text = dialog.SelectedPath;
DirectoryInfo folder = new DirectoryInfo(dialog.SelectedPath);
m_NeedMakePakList.Clear();
foreach (FileInfo file in folder.GetFiles())
{
m_NeedMakePakList.Add(file.Name);
}
}
}
//生成pak的保存路径
private void button3_Click(object sender, EventArgs e)
{
FolderBrowserDialog dialog = new FolderBrowserDialog();
dialog.Description = "请选择pak文件的保存路径";
if (dialog.ShowDialog() == DialogResult.OK)
{
if (string.IsNullOrEmpty(dialog.SelectedPath))
{
MessageBox.Show(this, "选择文件夹不能为空");
return;
}

m_OutPutPakPath = dialog.SelectedPath;
textBox3.Text = dialog.SelectedPath;
}
}
//批量打包
private void button4_Click(object sender, EventArgs e)
{
if (string.IsNullOrEmpty(m_InputFolderPath) || string.IsNullOrEmpty(m_OutPutPakPath) || string.IsNullOrEmpty(m_UnrealToolPath))
{
MessageBox.Show(this, "有至少一个文件夹的路径为空，请选择相应的路径");
return;
}

StringBuilder sb = new StringBuilder();
StringWriter sw = new StringWriter(sb);
JsonTextWriter json = new JsonTextWriter(sw);
json.Formatting = Formatting.Indented;
DateTime dateTime = DateTime.UtcNow;
int second = dateTime.Second;

string fileMD5 = StrToMD5(second.ToString());
json.WriteStartObject();
json.WritePropertyName("FileVersion");
json.WriteStartObject();
json.WritePropertyName("MD5");
json.WriteValue(fileMD5);
json.WriteEndObject();

if (!File.Exists(m_UnrealToolPath + @"\UnrealPak.exe"))
{
MessageBox.Show(this, "UnrealPak.exe文件没找到");
return;
}

json.WritePropertyName("Files");
json.WriteStartArray();

string assetNamePath = m_InputFolderPath.Split(' ')[0].Replace("\\", "/");
for (int i = 0; i < m_NeedMakePakList.Count; i++)
{
string assetPath = m_InputFolderPath + "\\" + m_NeedMakePakList[i];
string assetName = ReplaceFileSuffixes(m_NeedMakePakList[i]);
string md5String = StrToMD5(assetPath);
string outPath = m_OutPutPakPath + "\\" + assetName + ".pak";

ProcessStartInfo info = new ProcessStartInfo();
info.FileName = m_UnrealToolPath + @"\UnrealPak.exe";
info.Arguments = @outPath + @" " + @assetPath;
info.WindowStyle = ProcessWindowStyle.Minimized;
Process process = Process.Start(info);
process.WaitForExit();

json.WriteStartObject();
json.WritePropertyName("FileName");
json.WriteValue(assetName);
json.WritePropertyName("MD5");
json.WriteValue(md5String);
json.WriteEndObject();
}

MessageBox.Show("生成pak完毕");
json.WriteEndArray();
json.WriteEndObject();

string saveData = m_UnrealToolPath + ";" + m_InputFolderPath + ";" + m_OutPutPakPath;
File.WriteAllText(Environment.CurrentDirectory + "/save.txt", saveData);

File.WriteAllText(m_OutPutPakPath + "/Version.txt", sb.ToString());
}

public string ReplaceFileSuffixes(string fileName)
{
if (fileName.Contains("."))
{
fileName = fileName.Split('.')[0];
}
return fileName;
}

public string StrToMD5(string str)
{
string md5Str = "";
byte[] data = Encoding.GetEncoding("GB2312").GetBytes(str);
MD5 md5 = new MD5CryptoServiceProvider();
byte[] outBytes = md5.ComputeHash(data);

for (int i = 0; i < outBytes.Length; i++)
{
md5Str += outBytes[i].ToString("x2");
}

return md5Str.ToLower();
}
}
}

UE4下载Http（蓝图可调用）

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "UObject/Interface.h"
#include"Http.h"
#include "HttpRequestTest.generated.h"

UCLASS(BlueprintType)
class UHttpDownLoadContont : public UObject
{
GENERATED_BODY()

public:
UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "DownLoadContont")
TArray<FString> FileNameArray;
};

DECLARE_DYNAMIC_DELEGATE_OneParam(FHttpDownLoadSuccess, UHttpDownLoadContont*, DownLoadContont);
DECLARE_DYNAMIC_DELEGATE_TwoParams(FHttpDownLoadFailed, int32, ErrorCode, FString, ErrorMsg);
// This class does not need to be modified.
UINTERFACE(meta = (CannotImplementInterfaceInBlueprint))
class UHttpRequestTest : public UInterface
{
GENERATED_BODY()
};

/**
*
*/
class CHUNKSTEST_API IHttpRequestTest
{
GENERATED_BODY()

   // Add interface functions to this class. This is the class that will be inherited to implement this interface.
public:
   UFUNCTION(BlueprintCallable, Category = "HttpDownload")
   virtual void HttpDownLoad(const FString &URL, FHttpDownLoadSuccess OnSuccess, FHttpDownLoadFailed OnFailed);

//获取Mainfeast中的FileName
void HttpRequestComplete(FHttpRequestPtr Request, FHttpResponsePtr Response, bool bWasSuccessful, FHttpDownLoadSuccess OnSuccess, FHttpDownLoadFailed OnFailed);

private:
void LoadLocalVersion();
bool bCompareLocalAndServerFileHash(FString FileNameByServer, FString FileHashByServer);

FString LocalVersionContent;
TMap<FString, FString> LocalVersionFileNameMap;
};

// Fill out your copyright notice in the Description page of Project Settings.

#include "HttpRequestTest.h"
#include "HttpModule.h"
#include "JsonSerializer.h"
#include "ModuleManager.h"
#include "Paths.h"
#include "PlatformFilemanager.h"
#include "FileHelper.h"
//#include "Interfaces/IHttpResponse.h"

// Add default functionality here for any IHttpRequestTest functions that are not pure virtual.
void IHttpRequestTest::LoadLocalVersion()
{

   LocalVersionContent.Empty();
   LocalVersionFileNameMap.Empty();
   FString Path = FPaths::ConvertRelativePathToFull(FPaths::GameDir()) + "/Version.txt";
   IPlatformFile &PlatformFile = FPlatformFileManager::Get().GetPlatformFile();
   if (!PlatformFile.FileExists(*Path))
   {
       return;
   }
   FFileHelper::LoadFileToString(LocalVersionContent, *Path);
   if (LocalVersionContent.IsEmpty())
   {
       return;
   }

TSharedPtr<FJsonObject> JsonObject;
TSharedRef<TJsonReader<>> Reader = TJsonReaderFactory<>::Create(LocalVersionContent);

   if (FJsonSerializer::Deserialize(Reader, JsonObject))
   {
       UHttpDownLoadContont *DownLoadContont = NewObject<UHttpDownLoadContont>();
       DownLoadContont->FileNameArray.Empty();
       const TArray<TSharedPtr<FJsonValue>> Files = JsonObject->GetArrayField("Files");
       for (int i = 0; i < Files.Num(); i++)
       {
           const TSharedPtr<FJsonObject>* FileMessageObject;
           if (Files[i].Get()->TryGetObject(FileMessageObject))
           {
               FString FileName = FileMessageObject->Get()->GetStringField("FileName");
               FString FileHash = FileMessageObject->Get()->GetStringField("FileHash");
               LocalVersionFileNameMap.Add(FileName, FileHash);
           }
       }
   }
}

bool IHttpRequestTest::bCompareLocalAndServerFileHash(FString FileNameByServer, FString FileHashByServer)
{
   if (FileNameByServer.IsEmpty() || FileHashByServer.IsEmpty())
   {
       return false;
   }

   if (LocalVersionFileNameMap.Contains(FileNameByServer))
   {
       FString *HashValue = LocalVersionFileNameMap.Find(FileNameByServer);
       if (HashValue != nullptr && HashValue->Compare(FileHashByServer))
       {
           return false;
       }
   }

return true;
}

void IHttpRequestTest::HttpDownLoad(const FString &URL, FHttpDownLoadSuccess OnSuccess, FHttpDownLoadFailed OnFailed)
{
   if (URL.IsEmpty())
   {
       UE_LOG(LogClass, Log, TEXT("URL Is Null"));
       return;
   }

//LoadLocalVersion();

   FHttpModule& HttpModule = FModuleManager::LoadModuleChecked<FHttpModule>("HTTP");
   TSharedRef<class IHttpRequest> HttpRequest = HttpModule.Get().CreateRequest();
   HttpRequest->OnProcessRequestComplete().BindRaw(this, &IHttpRequestTest::HttpRequestComplete, OnSuccess, OnFailed);
   HttpRequest->SetURL(URL);
   HttpRequest->SetHeader(TEXT("Content-Type"), TEXT("application/json"));
   HttpRequest->SetVerb(TEXT("GET"));
   HttpRequest->ProcessRequest();
}

void IHttpRequestTest::HttpRequestComplete(FHttpRequestPtr Request, FHttpResponsePtr Response, bool bWasSuccessful, FHttpDownLoadSuccess OnSuccess, FHttpDownLoadFailed OnFailed)
{
   if (!bWasSuccessful || !Response.IsValid())
   {
       OnFailed.ExecuteIfBound(400,"NetWork Connect Failed");
       return;
   }

   if (!EHttpResponseCodes::IsOk(Response->GetResponseCode()))
   {
       OnFailed.ExecuteIfBound(Response->GetResponseCode(),"NetWork Connect Failed");
       return;
   }

   FString MainfestTxt = Response->GetContentAsString();
   if (MainfestTxt.IsEmpty())
   {
       OnFailed.ExecuteIfBound(401,"Mainfest Not Content");
       return;
   }

   TSharedPtr<FJsonObject> JsonObject;
   TSharedRef<TJsonReader<>> Reader = TJsonReaderFactory<>::Create(MainfestTxt);
   //将文件中的内容变成你需要的数据格式
   if (FJsonSerializer::Deserialize(Reader, JsonObject))
   {
       UHttpDownLoadContont *DownLoadContont = NewObject<UHttpDownLoadContont>();
       DownLoadContont->FileNameArray.Empty();
       const TArray<TSharedPtr<FJsonValue>> Files = JsonObject->GetArrayField("Files");
       for (int i = 0; i < Files.Num(); i++)
       {
           const TSharedPtr<FJsonObject>* FileMessageObject;
           if (Files[i].Get()->TryGetObject(FileMessageObject))
           {
               FString FileName = FileMessageObject->Get()->GetStringField("FileName");
               /*FString FileHash = FileMessageObject->Get()->GetStringField("FileHash");
               if (bCompareLocalAndServerFileHash(FileName, FileHash))
               {
                   DownLoadContont->FileNameArray.Add(FileName);
               }*/
               DownLoadContont->FileNameArray.Add(FileName);
           }
       }