如何将图像加载到类的数组中？

Question

我有以下代码在其中加载图像。 但是，每当我运行代码时，发现集合中的其他字段都是空的，并且在所有集合数据中只有一个图像，＆amp;生成以下错误。 indexoutofrangeException：索引不在数组的范围之外。 （包装器stelemref）system.Object.virt_stelemref_class_small_idepth（intptr，object）

下面是我的代码：

[System.Serializable]
public class CollectionDataClass
{
    public string name;
    public string id;
    public string thumbnail;
    public Texture2D collectionImage;
}

[System.Serializable]
public class DataClass
{
    [SerializeField] public CollectionDataClass[] collectionDataClass;
}

[SerializeField] private DataClass[] DataClassArray;

public IEnumerator BookCatogary(string reqParameter)
{
    BookCatogaryBodyClass BookCatogryClass = new BookCatogaryBodyClass(reqParameter);
    string json = JsonConvert.SerializeObject(BookCatogryClass);
    Debug.Log("==========================>" + json);

    var req = new UnityWebRequest(bookCategaryAPI, "POST");
    byte[] jsonToSend = new System.Text.UTF8Encoding().GetBytes(json);

    req.uploadHandler = (UploadHandler)new UploadHandlerRaw(jsonToSend);
    req.downloadHandler = (DownloadHandler)new DownloadHandlerBuffer();
    req.SetRequestHeader("Content-Type", "application/json");

    yield return req.SendWebRequest();

    if (req.isNetworkError)
    {
        Debug.Log("Error While Sending: " + req.error);
    }

    else
    {
        Debug.Log("Received: " + req.downloadHandler.text);
        string temp = req.downloadHandler.text;
        bookCatogaryObject = JsonConvert.DeserializeObject<BookCatogaryReceivedDataClass>(temp);
        catogaryCount = bookCatogaryObject.Data.Rows.Count;

        GetCatogariesName(catogaryCount);
        GenerateCollectionData();
    }
}


public void GenerateCollectionData()
{
    DataClassArray = new DataClass[bookCatogaryObject.Data.Rows.Count];

    for (int i = 0; i <= bookCatogaryObject.Data.Rows.Count; i++)
    {
        DataClassArray[i] = new DataClass();
        DataClassArray[i].collectionDataClass = new CollectionDataClass[bookCatogaryObject.Data.Rows[i].String.Count];

        for (int m = 0; m < bookCatogaryObject.Data.Rows[i].String.Count; m++)
        {
            DataClassArray[i].collectionDataClass[m] = new CollectionDataClass();

            DataClassArray[i].collectionDataClass[m].name = bookCatogaryObject.Data.Rows[i].String[m].CollectionTitle;
            DataClassArray[i].collectionDataClass[m].id = bookCatogaryObject.Data.Rows[i].String[m].Id;
            DataClassArray[i].collectionDataClass[m].thumbnail = bookCatogaryObject.Data.Rows[i].String[m].CollectionThumbnail;
            StartCoroutine(DownloadImage(mediaUrl: DataClassArray[i].collectionDataClass[m].thumbnail , bookCatogaryObject.Data.Rows[i].String.Count));
        }
    }
}

IEnumerator DownloadImage(string mediaUrl, int count)
{
    UnityWebRequest request = UnityWebRequestTexture.GetTexture(mediaUrl);
    yield return request.SendWebRequest();
    if (request.isNetworkError || request.isHttpError)
        Debug.Log(request.error);
    else
    {
        //collectionImage = ((DownloadHandlerTexture)request.downloadHandler).texture;
        //collectionImageContainer[count] = collectionImage;
        for (int i = 0; i <= bookCatogaryObject.Data.Rows.Count; i++)
        {
            DataClassArray[i] = new DataClass();
            DataClassArray[i].collectionDataClass = new CollectionDataClass[bookCatogaryObject.Data.Rows[i].String.Count];

            for (int m = 0; m < bookCatogaryObject.Data.Rows[i].String.Count; m++)
            {
                DataClassArray[i].collectionDataClass[m] = new CollectionDataClass();
                DataClassArray[i].collectionDataClass[m].collectionImage = ((DownloadHandlerTexture)request.downloadHandler).texture;
            }
        }
    }
}

Answer 1

这不是您问题的答案。我只是想向您展示如何使用临时当地人和对象初始化器来简化代码。它还使代码更有效，因为它消除了重复的索引和成员访问。但更重要的是，它使代码更可读。

public async void GenerateCollectionData()
{
    var rows = bookCatogaryObject.Data.Rows;
    DataClassArray = new DataClass[rows.Count];

    for (int i = 0; i < rows.Count; i++) {
        var currentString = rows[i].String;
        var dc = new DataClass {
            collectionDataClass = new CollectionDataClass[currentString.Count]
        };
        DataClassArray[i] = dc;

        for (int m = 0; m < currentString.Count; m++) {
            var collection = currentString[m];
            dc.collectionDataClass[m] = new CollectionDataClass {
                name = collection.CollectionTitle,
                id = collection.Id,
                thumbnail = collection.CollectionThumbnail,
                collectionImage = await GetImage(collection.CollectionThumbnail)
            };
        }
    }
}

Answer 2

因此，最后我找到了上述问题的答案，而不是使用coroutines，而是使用async任务将下载的纹理返回到generateCollectionData（）方法。
以下是参考代码：

public async void GenerateCollectionData()
{
    DataClassArray = new DataClass[bookCatogaryObject.Data.Rows.Count];

    for (int i = 0; i < bookCatogaryObject.Data.Rows.Count; i++)
    {
        DataClassArray[i] = new DataClass();
        DataClassArray[i].collectionDataClass = new CollectionDataClass[bookCatogaryObject.Data.Rows[i].String.Count];

        for (int m = 0; m < bookCatogaryObject.Data.Rows[i].String.Count; m++)
        {
            DataClassArray[i].collectionDataClass[m] = new CollectionDataClass();

            DataClassArray[i].collectionDataClass[m].name = bookCatogaryObject.Data.Rows[i].String[m].CollectionTitle;
            DataClassArray[i].collectionDataClass[m].id = bookCatogaryObject.Data.Rows[i].String[m].Id;
            DataClassArray[i].collectionDataClass[m].thumbnail = bookCatogaryObject.Data.Rows[i].String[m].CollectionThumbnail;
            DataClassArray[i].collectionDataClass[m].collectionImage = 
                await GetImage(bookCatogaryObject.Data.Rows[i].String[m].CollectionThumbnail);
        }
    }
}

public static async Task<Texture2D> GetImage(string imageURL)
{
    using (UnityWebRequest www = UnityWebRequestTexture.GetTexture(imageURL))
    {
        var asyncOperation = www.SendWebRequest();
        while (asyncOperation.isDone == false)
        {
            await Task.Delay(1000 / 30);
        }

        if (www.isNetworkError || www.isHttpError)
        {
            Debug.Log($"{www.error}, URL:{www.url}");
            return null;
        }
        else
        {
            return DownloadHandlerTexture.GetContent(www);
        }
    }
}