63 lines
2.0 KiB
C#
63 lines
2.0 KiB
C#
using System.Collections.Generic;
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using UnityEngine;
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using UnityEngine.Networking;
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using System.Threading.Tasks;
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using System;
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public class ImageLoader : MonoBehaviour
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{
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// 缓存字典
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private Dictionary<string, Sprite> imageCache = new Dictionary<string, Sprite>();
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public Sprite sprite;
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// 异步加载图片
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public async Task<Sprite> LoadImageAsync(string url)
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{
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if (!IsValidUrl(url))
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{
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return sprite;
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}
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// 如果缓存中已经有图片，则直接返回缓存的图片
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if (imageCache.ContainsKey(url))
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{
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return imageCache[url];
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}
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// 如果缓存中没有图片，则异步加载
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using (UnityWebRequest webRequest = UnityWebRequestTexture.GetTexture(url))
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{
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// 发送请求并等待响应
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var operation = webRequest.SendWebRequest();
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while (!operation.isDone)
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await Task.Yield(); // 等待请求完成，使用await以非阻塞的方式处理
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// 检查请求是否成功
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if (webRequest.result == UnityWebRequest.Result.Success)
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{
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// 获取下载的纹理
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Texture2D texture = ((DownloadHandlerTexture)webRequest.downloadHandler).texture;
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// 将纹理缓存
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imageCache[url] = TextureToSprite(texture);
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return imageCache[url];
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}
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else
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{
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//Debug.LogError("Failed to load image: " + webRequest.error);
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return sprite;
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}
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}
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}
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// 将Texture2D转换为Sprite
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Sprite TextureToSprite(Texture2D texture)
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{
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// 使用纹理的尺寸创建一个Sprite
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return Sprite.Create(texture, new Rect(0, 0, texture.width, texture.height), new Vector2(0.5f, 0.5f));
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}
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public static bool IsValidUrl(string url)
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{
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Uri uriResult;
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return Uri.TryCreate(url, UriKind.Absolute, out uriResult) && (uriResult.Scheme == Uri.UriSchemeHttp || uriResult.Scheme == Uri.UriSchemeHttps);
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}
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}
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