Unitywebrequest asynchronous Download

UnityWebRequest Asynchronous writing of

using System;
using System.Threading;
using System.Threading.Tasks;
using UnityEngine;
using UnityEngine.Networking;

public class Example : MonoBehaviour
{
    
    /// <summary>
    ///  Task cancellation source 
    /// </summary>
    CancellationTokenSource ts = new CancellationTokenSource();
    void Start()
    {
    
        SynchronizationContext.SetSynchronizationContext(SynchronizationContext.Current);
        Test();
    }

    private void OnDestroy()
    {
    
        //  Cancel access 
        ts.Cancel();
    }

    async void Test()
    {
    
        string url = "http://www.baidu.com";
        try
        {
    
            //  Update progress 
            var progress = new Progress<float>(v =>
            {
    
                Debug.Log(v);
            });
            // ts.Token  Create cancellation notification 
            //  Access link 
            var www = await RequestHelper.GetAsync(url, null, progress, ts.Token, 5000);
            //  If the access is cancelled , Because asynchronism throws AggregateException abnormal , The following statement will not be executed 
            Debug.Log(www.downloadHandler.text.Length);
        }
        catch(Exception ex)
        {
    
            Debug.LogError(ex);
        }
    }
}

public class RequestHelper
{
    
    public static async Task<UnityWebRequest> GetAsync(string url, int timeout = 10000)
    {
    
        var request = UnityGetRequest.Create(url, null, timeout);
        while (!request.isDone)
        {
    
            await Task.Delay(16);
        }
        return request.unityWebRequest;
    }
    public static async Task<UnityWebRequest> GetAsync(string url, IProgress<float> progress, int timeout = 10000)
    {
    
        var request = UnityGetRequest.Create(url, null, timeout);

        while (!request.isDone)
        {
    
            progress.Report(request.Progress);
            await Task.Delay(16);
        }
        return request.unityWebRequest;
    }
    public static async Task<UnityWebRequest> GetAsync(string url, IProgress<float> progress, CancellationToken token, int timeout = 10000)
    {
    
        var request = UnityGetRequest.Create(url, null, timeout);

        while (!request.isDone)
        {
    
            if (token.IsCancellationRequested)
            {
    
                token.ThrowIfCancellationRequested();
            }
            progress.Report(request.Progress);
            await Task.Delay(16);
        }
        return request.unityWebRequest;
    }
    public static async Task<UnityWebRequest> GetAsync(string url, WWWForm formData,  IProgress<float> progress, CancellationToken token, int timeout=10000)
    {
    
        var request = UnityGetRequest.Create(url, formData, timeout);

        while (!request.isDone)
        {
    
            if (token.IsCancellationRequested)
            {
    
                token.ThrowIfCancellationRequested();
            }
            progress.Report(request.Progress);
            await Task.Delay(16);
        }
        return request.unityWebRequest;
    }

    public static async Task<UnityWebRequest> PostAsync(string url, WWWForm formData, IProgress<float> progress, CancellationToken token, int timeout = 10000)
    {
    
        var request = UnityPostRequest.Create(url, formData, timeout);

        while (!request.isDone)
        {
    
            if (token.IsCancellationRequested)
            {
    
                token.ThrowIfCancellationRequested();
            }
            progress.Report(request.Progress);
            await Task.Delay(16);
        }
        return request.unityWebRequest;
    }

    interface IUnityWebRequest
    {
    
        bool isDone {
     get; }
        float Progress {
     get; }
        UnityWebRequest unityWebRequest {
     get; }
    }
    class UnityGetRequest : IUnityWebRequest
    {
    
        UnityWebRequest request;
        bool IUnityWebRequest.isDone => request.isDone;

        float IUnityWebRequest.Progress => request.downloadProgress;

        UnityWebRequest IUnityWebRequest.unityWebRequest => request;

        public static IUnityWebRequest Create(string url, WWWForm formData, int timeout)
        {
    
            UnityGetRequest unityGetRequest = new UnityGetRequest();
            unityGetRequest.request = UnityWebRequest.Get(url);
            unityGetRequest.request.timeout = timeout;
            if (formData != null)
            {
    
                foreach (var header in formData.headers)
                {
    
                    unityGetRequest.request.SetRequestHeader(header.Key, header.Value);
                }
            }
            unityGetRequest.request.SendWebRequest();
            return unityGetRequest;
        }
    }
    class UnityPostRequest : IUnityWebRequest
    {
    
        UnityWebRequest request;

        bool IUnityWebRequest.isDone => request.isDone;

        float IUnityWebRequest.Progress => request.uploadProgress;

        UnityWebRequest IUnityWebRequest.unityWebRequest => request;

        public static IUnityWebRequest Create(string url, WWWForm formData, int timeout)
        {
    
            UnityPostRequest unityPostRequest = new UnityPostRequest();
            unityPostRequest.request = UnityWebRequest.Post(url, formData);
            unityPostRequest.request.timeout = timeout;
            unityPostRequest.request.SendWebRequest();
            return unityPostRequest;
        }
    }
}