|
|
@@ -0,0 +1,116 @@
|
|
|
+Public Class MyImage
|
|
|
+ Inherits Image
|
|
|
+
|
|
|
+#Region "辅助属性注册"
|
|
|
+
|
|
|
+ ''' <summary>
|
|
|
+ ''' 网络图片的缓存有效期。
|
|
|
+ ''' 在这个时间后，才会重新尝试下载图片。
|
|
|
+ ''' </summary>
|
|
|
+ Public FileCacheExpiredTime As New TimeSpan(7, 0, 0, 0) '7 天
|
|
|
+
|
|
|
+ ''' <summary>
|
|
|
+ ''' 是否允许将网络图片存储到本地用作缓存。
|
|
|
+ ''' </summary>
|
|
|
+ Public Property EnableCache As Boolean
|
|
|
+ Get
|
|
|
+ Return _EnableCache
|
|
|
+ End Get
|
|
|
+ Set(value As Boolean)
|
|
|
+ _EnableCache = value
|
|
|
+ End Set
|
|
|
+ End Property
|
|
|
+ Private _EnableCache As Boolean = True
|
|
|
+
|
|
|
+ '将 Source 属性映射到 XAML
|
|
|
+ Public Shared Shadows ReadOnly SourceProperty As DependencyProperty = DependencyProperty.Register(
|
|
|
+ "Source", GetType(String), GetType(MyImage), New PropertyMetadata(New PropertyChangedCallback(
|
|
|
+ Sub(sender, e) If sender IsNot Nothing Then CType(sender, MyImage).Source = e.NewValue.ToString())))
|
|
|
+
|
|
|
+#End Region
|
|
|
+
|
|
|
+ Private _Source As String = ""
|
|
|
+ ''' <summary>
|
|
|
+ ''' 与 Image 的 Source 类似。
|
|
|
+ ''' 若输入以 http 开头的字符串，则会尝试下载图片然后显示，图片会保存为本地缓存。
|
|
|
+ ''' 支持 WebP 格式的图片。
|
|
|
+ ''' </summary>
|
|
|
+ Public Shadows Property Source As String '覆写 Image 的 Source 属性
|
|
|
+ Get
|
|
|
+ Return _Source
|
|
|
+ End Get
|
|
|
+ Set(value As String)
|
|
|
+ If value = "" Then value = Nothing
|
|
|
+ If _Source = value Then Exit Property
|
|
|
+ _Source = value
|
|
|
+ Dim TempPath As String = $"{PathTemp}MyImage\{GetHash(value)}.png"
|
|
|
+ Try
|
|
|
+ '空
|
|
|
+ If value Is Nothing Then
|
|
|
+ MyBase.Source = Nothing
|
|
|
+ Exit Property
|
|
|
+ End If
|
|
|
+ '本地图片
|
|
|
+ If Not value.StartsWithF("http") Then
|
|
|
+ MyBase.Source = New MyBitmap(value)
|
|
|
+ Exit Property
|
|
|
+ End If
|
|
|
+ '从缓存加载网络图片
|
|
|
+ If EnableCache AndAlso File.Exists(TempPath) Then
|
|
|
+ MyBase.Source = New MyBitmap(TempPath)
|
|
|
+ If (Date.Now - File.GetCreationTime(TempPath)) < FileCacheExpiredTime Then
|
|
|
+ Exit Property '无需刷新缓存
|
|
|
+ Else
|
|
|
+ File.Delete(TempPath) '需要刷新缓存
|
|
|
+ End If
|
|
|
+ Else
|
|
|
+ MyBase.Source = Nothing '清空显示
|
|
|
+ End If
|
|
|
+ '下载网络图片
|
|
|
+ RunInNewThread(
|
|
|
+ Sub()
|
|
|
+ Dim Url As String = value '重新捕获变量，以检测在下载过程中 Source 被修改的情况
|
|
|
+ Dim Retried As Boolean = False
|
|
|
+RetryStart:
|
|
|
+ Dim TempDownloadingPath As String = TempPath & RandomInteger(0, 10000000)
|
|
|
+ Try
|
|
|
+ Log("[MyImage] 正在下载图片：" & Url)
|
|
|
+ NetDownload(Url, TempDownloadingPath, True)
|
|
|
+ If Url <> Source Then
|
|
|
+ '若 Source 在下载时被修改，则不显示
|
|
|
+ File.Delete(TempDownloadingPath)
|
|
|
+ ElseIf EnableCache Then
|
|
|
+ '保存缓存并显示
|
|
|
+ Rename(TempDownloadingPath, TempPath)
|
|
|
+ RunInUi(Sub() MyBase.Source = New MyBitmap(TempPath))
|
|
|
+ Else
|
|
|
+ '直接显示
|
|
|
+ RunInUiWait(Sub() MyBase.Source = New MyBitmap(TempDownloadingPath))
|
|
|
+ File.Delete(TempDownloadingPath)
|
|
|
+ End If
|
|
|
+ Catch ex As Exception
|
|
|
+ Try
|
|
|
+ File.Delete(TempDownloadingPath)
|
|
|
+ Catch
|
|
|
+ End Try
|
|
|
+ If Not Retried Then
|
|
|
+ Log(ex, $"下载图片可重试地失败（{Url}）", LogLevel.Developer)
|
|
|
+ Retried = True
|
|
|
+ Thread.Sleep(1000)
|
|
|
+ GoTo RetryStart
|
|
|
+ Else
|
|
|
+ Log(ex, $"下载图片失败（{Url}）", LogLevel.Hint)
|
|
|
+ End If
|
|
|
+ End Try
|
|
|
+ End Sub, "MyImage PicLoader " & GetUuid() & "#", ThreadPriority.BelowNormal)
|
|
|
+ Catch ex As Exception
|
|
|
+ Log(ex, $"加载图片失败（{value}）", LogLevel.Hint)
|
|
|
+ Try
|
|
|
+ File.Delete(TempPath) '删除缓存，以免缓存出现问题导致一直加载失败
|
|
|
+ Catch
|
|
|
+ End Try
|
|
|
+ End Try
|
|
|
+ End Set
|
|
|
+ End Property
|
|
|
+
|
|
|
+End Class
|
龙腾猫跃