WindowsFormsApplicationBase.OpenForms 属性

public:
 property System::Windows::Forms::FormCollection ^ OpenForms { System::Windows::Forms::FormCollection ^ get(); };

public System.Windows.Forms.FormCollection OpenForms { get; }

member this.OpenForms : System.Windows.Forms.FormCollection

Public ReadOnly Property OpenForms As FormCollection

属性值

包含应用程序的所有打开窗体的集合。

示例

此示例循环访问应用程序的打开窗体，选择当前线程直接访问的窗体，并在 控件中 ListBox 显示其标题。 此示例要求Windows 窗体应用程序具有名为 的Form1窗体，其中包含名为 ListBox1的列表框。

Private Sub GetOpenFormTitles()
    Dim formTitles As New Collection

    Try
        For Each f As Form In My.Application.OpenForms
            If Not f.InvokeRequired Then
                ' Can access the form directly.
                formTitles.Add(f.Text)
            End If
        Next
    Catch ex As Exception
        formTitles.Add("Error: " & ex.Message)
    End Try

    Form1.ListBox1.DataSource = formTitles
End Sub

此示例循环访问应用程序的打开窗体，并在 控件中 ListBox 显示其标题。

Private Sub GetOpenFormTitles()
    Dim formTitles As New Collection

    Try
        For Each f As Form In My.Application.OpenForms
            ' Use a thread-safe method to get all form titles.
            formTitles.Add(GetFormTitle(f))
        Next
    Catch ex As Exception
        formTitles.Add("Error: " & ex.Message)
    End Try

    Form1.ListBox1.DataSource = formTitles
End Sub

Private Delegate Function GetFormTitleDelegate(f As Form) As String
Private Function GetFormTitle(f As Form) As String
    ' Check if the form can be accessed from the current thread.
    If Not f.InvokeRequired Then
        ' Access the form directly.
        Return f.Text
    Else
        ' Marshal to the thread that owns the form. 
        Dim del As GetFormTitleDelegate = AddressOf GetFormTitle
        Dim param As Object() = {f}
        Dim result As System.IAsyncResult = f.BeginInvoke(del, param)
        ' Give the form's thread a chance process function.
        System.Threading.Thread.Sleep(10)
        ' Check the result.
        If result.IsCompleted Then
            ' Get the function's return value.
            Return "Different thread: " & f.EndInvoke(result).ToString
        Else
            Return "Unresponsive thread"
        End If
    End If
End Function

注解

属性 My.Application.OpenForms 获取应用程序的所有打开窗体的集合。 该行为与 Application.OpenForms 属性相同。

可用性（按项目类型）

另请参阅

• FormCollection
• OpenForms
• 对象 (Visual Basic)