Unity 매뉴얼: DownloadHandler 개요

이 문서는 Unity의 DownloadHandler에 대한 안내서입니다. DownloadHandler는 UnityWebRequest와 함께 사용되어 데이터를 다운로드할 때 유용하게 활용됩니다. 이 문서에서는 다양한 DownloadHandler 유형과 그 사용 사례에 대해 설명합니다.

DownloadHandler 유형

다양한 DownloadHandler 유형이 있으며, 각각의 사용 용도에 따라 차별화됩니다.

사용 예제

각 DownloadHandler의 사용 예제는 다음과 같습니다:

1. DownloadHandlerBuffer

using UnityEngine;
using UnityEngine.Networking;
using System.Collections;

public class MyBehaviour : MonoBehaviour {
    void Start() {
        StartCoroutine(GetText());
    }

    IEnumerator GetText() {
        UnityWebRequest www = new UnityWebRequest("https://www.my-server.com");
        www.downloadHandler = new DownloadHandlerBuffer();
        yield return www.SendWebRequest();

        if (www.result != UnityWebRequest.Result.Success) {
            Debug.Log(www.error);
        }
        else {
            Debug.Log(www.downloadHandler.text);
        }
    }
}

2. DownloadHandlerFile

using System.Collections;
using System.IO;
using UnityEngine;
using UnityEngine.Networking;

public class FileDownloader : MonoBehaviour {
    void Start () {
        StartCoroutine(DownloadFile());
    }

    IEnumerator DownloadFile() {
        var uwr = new UnityWebRequest("https://unity3d.com/");
        string path = Path.Combine(Application.persistentDataPath, "unity3d.html");
        uwr.downloadHandler = new DownloadHandlerFile(path);
        yield return uwr.SendWebRequest();

        if (uwr.result != UnityWebRequest.Result.Success) {
            Debug.LogError(uwr.error);
        }
        else {
            Debug.Log("File successfully downloaded and saved to " + path);
        }
    }
}

3. DownloadHandlerTexture

using UnityEngine;
using UnityEngine.UI;
using UnityEngine.Networking;
using System.Collections;

[RequireComponent(typeof(Image))]
public class ImageDownloader : MonoBehaviour {
    Image _img;

    void Start () {
        _img = GetComponent<Image>();
        Download("https://www.mysite.com/myimage.png");
    }

    public void Download(string url) {
        StartCoroutine(LoadFromWeb(url));
    }

    IEnumerator LoadFromWeb(string url) {
        UnityWebRequest wr = new UnityWebRequest(url);
        DownloadHandlerTexture texDl = new DownloadHandlerTexture(true);
        wr.downloadHandler = texDl;
        yield return wr.SendWebRequest();

        if (wr.result == UnityWebRequest.Result.Success) {
            Texture2D t = texDl.texture;
            Sprite s = Sprite.Create(t, new Rect(0, 0, t.width, t.height), Vector2.zero, 1f);
            _img.sprite = s;
        }
    }
}

4. DownloadHandlerAssetBundle

using UnityEngine;
using UnityEngine.Networking;
using System.Collections;

public class MyBehaviour : MonoBehaviour {
    void Start() {
        StartCoroutine(GetAssetBundle());
    }

    IEnumerator GetAssetBundle() {
        UnityWebRequest www = new UnityWebRequest("https://www.my-server.com");
        DownloadHandlerAssetBundle handler = new DownloadHandlerAssetBundle(www.url, uint.MaxValue);
        www.downloadHandler = handler;
        yield return www.SendWebRequest();

        if (www.result != UnityWebRequest.Result.Success) {
            Debug.Log(www.error);
        }
        else {
            AssetBundle bundle = handler.assetBundle;
        }
    }
}

5. DownloadHandlerAudioClip

using System.Collections;
using UnityEngine;
using UnityEngine.Networking;

public class AudioDownloader : MonoBehaviour {
    void Start () {
        StartCoroutine(GetAudioClip());
    }

    IEnumerator GetAudioClip() {
        using (var uwr = UnityWebRequestMultimedia.GetAudioClip("https://myserver.com/mysound.ogg", AudioType.OGGVORBIS)) {
            yield return uwr.SendWebRequest();

            if (uwr.result != UnityWebRequest.Result.Success) {
                Debug.LogError(uwr.error);
            } else {
                AudioClip clip = DownloadHandlerAudioClip.GetContent(uwr);
                // use audio clip
            }
        }
    }
}

6. DownloadHandlerScript

using UnityEngine;
using UnityEngine.Networking;

public class LoggingDownloadHandler : DownloadHandlerScript {
    public LoggingDownloadHandler(): base() { }

    public LoggingDownloadHandler(byte[] buffer): base(buffer) { }

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

    protected override bool ReceiveData(byte[] data, int dataLength) {
||
|---|
            Debug.Log("LoggingDownloadHandler :: ReceiveData - received a null/empty buffer");
            return false;
        }
        Debug.Log(string.Format("LoggingDownloadHandler :: ReceiveData - received {0} bytes", dataLength));
        return true;
    }

    protected override void CompleteContent() {
        Debug.Log("LoggingDownloadHandler :: CompleteContent - DOWNLOAD COMPLETE!");
    }

    protected override void ReceiveContentLengthHeader(ulong contentLength) {
        Debug.Log(string.Format("LoggingDownloadHandler :: ReceiveContentLength - length {0}", contentLength));
    }
}

결론

Unity의 DownloadHandler는 다양한 데이터를 다운로드하고 처리하는 데 유용한 클래스입니다. 각 DownloadHandler는 특정 용도를 위해 설계 되었으며, 상황에 맞는 적절한 Handler를 선택하여 사용하는 것이 중요합니다. 본 문서를 통해 DownloadHandler의 기본적인 사용 방법에 대해 이해할 수 있기를 바랍니다.