Unity C# 网络学习（十）——UnityWebRequest（二）

一.Unity提供的自定义获取数据DownLoadHandler

Unity帮我们定义好了一些相关的类，用于解析下载下来的数据的类，使用对应的类处理下载数据，他们就会在内部将下载的数据处理为对应的类型，方便使用

1.DownLoadHandlerBuffer（用于简单的数据存储，得到对应的二进制数据）

private IEnumerator DownLoadBuffer()
{
    UnityWebRequest req = new UnityWebRequest("http://192.168.1.103:8080/Http_Server/xxx.jpg",
        UnityWebRequest.kHttpVerbGET);
    DownloadHandlerBuffer downloadHandlerBuffer = new DownloadHandlerBuffer();
    req.downloadHandler = downloadHandlerBuffer;
    yield return req.SendWebRequest();
    if (req.result == UnityWebRequest.Result.Success)
    {
        byte[] buffer = downloadHandlerBuffer.data;
        Debug.Log(buffer.Length);
        Debug.Log("下载成功!");
    }
    else
    {
        Debug.Log("下载失败:"+req.result);
    }
}

2.DownLoadHandlerFile（用于下载文件并将文件保存到磁盘，内存占用少）

private IEnumerator DownLoadFile()
{
    UnityWebRequest req = new UnityWebRequest("http://192.168.1.103:8080/Http_Server/xxx.jpg", UnityWebRequest.kHttpVerbGET);
    req.downloadHandler = new DownloadHandlerFile(Application.persistentDataPath + "/WebDownLoad.jpg");
    yield return req.SendWebRequest();
    Debug.Log(req.result);
}

3.DownLoadHandlerTexture（用于下载图片）

private IEnumerator DownLoadTexture()
{
    UnityWebRequest req = new UnityWebRequest("http://192.168.1.103:8080/Http_Server/xxx.jpg", UnityWebRequest.kHttpVerbGET);
    DownloadHandlerTexture downloadHandlerTexture = new DownloadHandlerTexture();
    req.downloadHandler = downloadHandlerTexture;
    yield return req.SendWebRequest();
    if (req.result == UnityWebRequest.Result.Success)
    {
        Debug.Log(downloadHandlerTexture.texture);
        Debug.Log("下载成功!");
    }
    else
    {
        Debug.Log("下载失败:"+req.result);
    }
}

4.DownLoadHandlerAssetBundle（用于提取AssetBundle）

private IEnumerator DownLoadAssetBundle()
{
    UnityWebRequest req = new UnityWebRequest("http://192.168.1.103:8080/Http_Server/photo.ywj", UnityWebRequest.kHttpVerbGET);
    DownloadHandlerAssetBundle downloadHandlerAssetBundle = new DownloadHandlerAssetBundle(req.url,0);
    req.downloadHandler = downloadHandlerAssetBundle;
    yield return req.SendWebRequest();
    if (req.result == UnityWebRequest.Result.Success)
    {
        Debug.Log(downloadHandlerAssetBundle.assetBundle.name);
        Debug.Log("下载成功!");
    }
    else
    {
        Debug.Log("下载失败:"+req.result);
    }
}

5.DownLoadHandlerAudioClip（用于下载音频文件）

private IEnumerator DownLoadAudioClip()
{
    UnityWebRequest req = new UnityWebRequest("http://192.168.1.103:8080/Http_Server/music.mp3", UnityWebRequest.kHttpVerbGET);
    DownloadHandlerAudioClip downloadHandlerAudioClip = new DownloadHandlerAudioClip(req.url,AudioType.MPEG);
    req.downloadHandler = downloadHandlerAudioClip;
    yield return req.SendWebRequest();
    if (req.result == UnityWebRequest.Result.Success)
    {
        Debug.Log(downloadHandlerAudioClip.audioClip);
        Debug.Log("下载成功!");
    }
    else
    {
        Debug.Log("下载失败:"+req.result);
    }
}

二.自定义DownLoadHandler去处理数据

• 当我们对数据有需要进行拓展时，可以继承自DownloadHandlerScript类对其拓展使用

public class CustomDownLoadFileHandler : DownloadHandlerScript
{
    
    private string _savePath;
    private byte[] _cacheBytes;
    private int _index;
    public CustomDownLoadFileHandler() : base()
    {
    
    }
    public CustomDownLoadFileHandler(byte[] bytes) : base(bytes)
    {
    
        
    }
    public CustomDownLoadFileHandler(string path) : base()
    {
    
        this._savePath = path;
    }

    protected override byte[] GetData()
    {
    
        return _cacheBytes;
    }

    //从网络收到数据后，每帧会调用的方法
    protected override bool ReceiveData(byte[] buffer, int dataLength)
    {
    
        buffer.CopyTo(_cacheBytes,_index);
        _index += dataLength;
        return true;
    }

    //从服务器收到contentLength标头时会调用
    protected override void ReceiveContentLengthHeader(ulong contentLength)
    {
    
        _cacheBytes = new byte[contentLength];
    }

    //消息收完了，会自动调用的方法
    protected override void CompleteContent()
    {
    
        File.WriteAllBytes(_savePath,_cacheBytes);
    }
}

进行测试

private IEnumerator CustomDownLoadFile()
{
    UnityWebRequest unityWebRequest = new UnityWebRequest("http://192.168.1.103:8080/Http_Server/xxx.jpg",
        UnityWebRequest.kHttpVerbGET);
    unityWebRequest.downloadHandler = new CustomDownLoadFileHandler(Application.persistentDataPath+"/zzsCustom.jpg");
    yield return unityWebRequest.SendWebRequest();
    Debug.Log(unityWebRequest.result);
}

三.自定义DownLoadHandler练习处理

public class DownLoadHandlerMsg : DownloadHandlerScript
{
    
    private byte[] _cacheBuffer;
    private int _index;
    private MsgBase _msgBase;
    public DownLoadHandlerMsg()
    {
    
        
    }

    public T GetMsg<T>() where T : MsgBase
    {
    
        return _msgBase as T;
    }

    protected override byte[] GetData()
    {
    
        return _cacheBuffer;
    }

    protected override void ReceiveContentLengthHeader(ulong contentLength)
    {
    
        _cacheBuffer = new byte[contentLength];
    }

    protected override bool ReceiveData(byte[] buffer, int dataLength)
    {
    
        buffer.CopyTo(_cacheBuffer,_index);
        _index += dataLength;
        return true;
    }

    protected override void CompleteContent()
    {
    
        int index = 0;
        int msgId = BitConverter.ToInt32(_cacheBuffer,index);
        index += 4;
        int msgLength = BitConverter.ToInt32(_cacheBuffer, index);
        index += 4;
        switch (msgId)
        {
    
            case 1001:
                _msgBase = new PlayerMsg();
                _msgBase.Reading(_cacheBuffer, index);
                break;
        }
        Debug.Log(_msgBase == null ? "消息Id错误!" : "消息解析成功!");
    }
}

测试代码

private IEnumerator Start()
{
    UnityWebRequest unityWebRequest = new UnityWebRequest("", UnityWebRequest.kHttpVerbGET);
    unityWebRequest.downloadHandler = new DownLoadHandlerMsg();
    yield return unityWebRequest.SendWebRequest();
    Debug.Log(unityWebRequest.result);
}