WebView2 控件进程和状态管理
进程管理
BrowserProcessId 属性
- 描述:获取浏览器进程的 ProcessID
- 类型:Long
- 示例:
vb
' 获取并显示浏览器进程ID
Private Sub ShowBrowserProcessInfo()
Dim pid As Long
pid = WebView21.BrowserProcessId
Debug.Print "浏览器进程ID: " & pid
End Sub
ProcessFailed 事件处理
- 描述:处理WebView2相关进程失败的情况
- 示例:
vb
Private Sub WebView21_ProcessFailed(ByVal Kind As wv2ProcessFailedKind)
Select Case Kind
Case wv2ProcessFailedKind.wv2ProcessFailedKindBrowserProcessExited
' 浏览器进程退出
HandleBrowserCrash
Case wv2ProcessFailedKind.wv2ProcessFailedKindRenderProcessExited
' 渲染进程退出
HandleRenderProcessCrash
Case wv2ProcessFailedKind.wv2ProcessFailedKindFrameRenderProcessExited
' 框架渲染进程退出
HandleFrameProcessCrash
End Select
End Sub
Private Sub HandleBrowserCrash()
' 记录错误
LogError "浏览器进程崩溃"
' 尝试恢复
If MsgBox("浏览器进程已终止。是否重新加载页面?", _
vbQuestion + vbYesNo) = vbYes Then
WebView21.Reload
End If
End Sub
Private Sub HandleRenderProcessCrash()
' 记录错误
LogError "渲染进程崩溃"
' 显示错误页面
WebView21.LoadHtml "<html><body>" & _
"<h1>页面渲染失败</h1>" & _
"<p>请刷新页面重试。</p>" & _
"</body></html>"
End Sub
暂停和恢复
暂停/恢复支持检查
- 描述:检查是否支持暂停和恢复功能
- 属性:
SupportsSuspendResumeFeatures As Boolean
- 示例:
vb
' 检查是否支持暂停/恢复功能
Private Function CanUseSuspendFeatures() As Boolean
CanUseSuspendFeatures = WebView21.SupportsSuspendResumeFeatures
End Function
Suspend 方法
- 描述:暂停 WebView2 的处理和渲染
- 用途:用于实现标签页功能,减少非活动标签的资源占用
- 示例:
vb
' 暂停当前标签页
Private Sub SuspendTab()
If WebView21.SupportsSuspendResumeFeatures Then
WebView21.Suspend
End If
End Sub
Resume 方法
- 描述:恢复之前暂停的 WebView2 处理和渲染
- 示例:
vb
' 恢复暂停的标签页
Private Sub ResumeTab()
If WebView21.SupportsSuspendResumeFeatures Then
WebView21.Resume
End If
End Sub
IsSuspended 属性
- 描述:获取 WebView2 是否处于暂停状态
- 类型:Boolean
- 示例:
vb
' 检查并处理暂停状态
Private Sub HandleTabActivation()
If WebView21.SupportsSuspendResumeFeatures Then
If WebView21.IsSuspended Then
' 标签页被激活,恢复处理
WebView21.Resume
End If
End If
End Sub
完整的标签页管理示例
vb
' 标签页类型定义
Private Type TabInfo
WebView As WebView2
Caption As String
IsSuspended As Boolean
End Type
' 标签页集合
Private Tabs() As TabInfo
Private ActiveTabIndex As Long
' 切换到指定标签页
Private Sub SwitchToTab(ByVal Index As Long)
If Index < 0 Or Index > UBound(Tabs) Then Exit Sub
' 暂停当前活动标签页
If ActiveTabIndex >= 0 And ActiveTabIndex <= UBound(Tabs) Then
With Tabs(ActiveTabIndex)
If Not .IsSuspended And .WebView.SupportsSuspendResumeFeatures Then
.WebView.Suspend
.IsSuspended = True
End If
.WebView.Visible = False
End With
End If
' 激活新标签页
With Tabs(Index)
If .IsSuspended And .WebView.SupportsSuspendResumeFeatures Then
.WebView.Resume
.IsSuspended = False
End If
.WebView.Visible = True
.WebView.SetFocus
End With
ActiveTabIndex = Index
UpdateTabButtons
End Sub
' 创建新标签页
Private Sub CreateNewTab(ByVal Url As String)
' 扩展数组
ReDim Preserve Tabs(UBound(Tabs) + 1)
Dim newIndex As Long
newIndex = UBound(Tabs)
' 创建新的WebView2控件
With Tabs(newIndex)
Set .WebView = Controls.Add("WebView2Control.WebView2", "tab" & newIndex)
' 配置WebView2
With .WebView
.Move TabContainer.Left, TabContainer.Top, _
TabContainer.Width, TabContainer.Height
.IsStatusBarEnabled = False
.Navigate Url
End With
.Caption = "新标签页"
.IsSuspended = False
End With
' 切换到新标签页
SwitchToTab newIndex
End Sub
' 关闭标签页
Private Sub CloseTab(ByVal Index As Long)
If Index < 0 Or Index > UBound(Tabs) Then Exit Sub
' 移除WebView2控件
Controls.Remove Tabs(Index).WebView.Name
' 重组数组
For i = Index To UBound(Tabs) - 1
Tabs(i) = Tabs(i + 1)
Next i
ReDim Preserve Tabs(UBound(Tabs) - 1)
' 如果关闭的是当前标签页,切换到其他标签页
If Index = ActiveTabIndex Then
If UBound(Tabs) >= 0 Then
SwitchToTab IIf(Index > 0, Index - 1, 0)
End If
ElseIf Index < ActiveTabIndex Then
ActiveTabIndex = ActiveTabIndex - 1
End If
UpdateTabButtons
End Sub
这个示例展示了如何结合使用暂停/恢复功能来实现一个完整的多标签页浏览器。它包含了:
- 标签页数据结构
- 标签页切换逻辑
- 新建标签页功能
- 关闭标签页功能
- 资源管理优化