工单 优化 ，增加图片

OrderSupportTicket/ViewModels/ChatMessageViewModel.cs

@@ -1,6 +1,10 @@
-using OrderSupportTicket.Models.Api;
+using OrderSupportTicket.Models.Api;
 using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.Globalization;
+using System.Linq;
+using System.Threading.Tasks;
 using WPFCommon.Models;
 
 namespace OrderSupportTicket.ViewModels;
@@ -22,6 +26,7 @@ public sealed class ChatMessageViewModel : BindableBaseEx
     {
         if (dto == null)
             throw new ArgumentNullException(nameof(dto));
+        Attachments = new ObservableCollection<ChatAttachmentViewModel>();
         MessageId = dto.MessageId;
         SequenceNo = dto.SequenceNo;
         SenderType = dto.SenderType;
@@ -33,6 +38,7 @@ public sealed class ChatMessageViewModel : BindableBaseEx
             ? "该消息已撤回"
             : (dto.Text ?? string.Empty);
         CreatedAt = ParseTimestamp(dto.CreatedAt);
+        ReplaceAttachments(dto.Attachments);
     }
 
     /// <summary>
@@ -81,9 +87,18 @@ public sealed class ChatMessageViewModel : BindableBaseEx
     public string Content
     {
         get => _content;
-        private set => SetValue(ref _content, value);
+        private set
+        {
+            if (SetValue(ref _content, value))
+                RaisePropertyChanged(nameof(HasText));
+        }
     }
 
+    /// <summary>
+    /// 是否有可展示的文字内容。
+    /// </summary>
+    public bool HasText => !string.IsNullOrWhiteSpace(Content);
+
     /// <summary>
     /// 消息是否已撤回。
     /// </summary>
@@ -106,6 +121,16 @@ public sealed class ChatMessageViewModel : BindableBaseEx
         }
     }
 
+    /// <summary>
+    /// 消息中的公开图片附件。
+    /// </summary>
+    public ObservableCollection<ChatAttachmentViewModel> Attachments { get; }
+
+    /// <summary>
+    /// 是否包含图片附件。
+    /// </summary>
+    public bool HasAttachments => Attachments.Count > 0;
+
     /// <summary>
     /// 当前消息是否由客户发送。
     /// </summary>
@@ -120,6 +145,50 @@ public sealed class ChatMessageViewModel : BindableBaseEx
             ? string.Empty
             : CreatedAt.ToLocalTime().ToString("MM-dd HH:mm", CultureInfo.CurrentCulture);
 
+    /// <summary>
+    /// 使用服务端最新数据更新消息。短时图片地址会随每次查询变化，因此需要刷新附件。
+    /// </summary>
+    public void UpdateFrom(TicketMessageDto dto)
+    {
+        if (dto == null)
+            return;
+
+        SenderDisplayName = string.IsNullOrWhiteSpace(dto.SenderName)
+            ? (IsCustomer ? "我" : "客服")
+            : dto.SenderName;
+        IsRecalled = dto.Recalled;
+        Content = dto.Recalled
+            ? "该消息已撤回"
+            : (dto.Text ?? string.Empty);
+        CreatedAt = ParseTimestamp(dto.CreatedAt);
+        ReplaceAttachments(dto.Attachments);
+    }
+
+    private void ReplaceAttachments(IEnumerable<TicketAttachmentDto> attachments)
+    {
+        Attachments.Clear();
+        foreach (var dto in attachments ?? Enumerable.Empty<TicketAttachmentDto>())
+        {
+            if (dto == null)
+                continue;
+            Attachments.Add(new ChatAttachmentViewModel(dto));
+        }
+        RaisePropertyChanged(nameof(HasAttachments));
+        _ = LoadAttachmentsAsync();
+    }
+
+    private async Task LoadAttachmentsAsync()
+    {
+        try
+        {
+            await Task.WhenAll(Attachments.Select(item => item.LoadAsync()));
+        }
+        catch
+        {
+            // 单张图片加载失败时保留占位提示，不影响文字留言显示。
+        }
+    }
+
     private static DateTimeOffset ParseTimestamp(string value)
     {
         if (DateTimeOffset.TryParse(