Question

我是VB.net的新手，我正在尝试使用VB.net在按钮点击应用程序上创建截图捕获。当我尝试使用按钮点击VB.net中的表单截取屏幕截图时，表单出现在屏幕截图中。当我尝试使用me.hide或Me.visible = false或me.sendtoback隐藏表单时，表单仍然出现在屏幕截图中。最好的部分是sendtoback在一个系统中工作，但在另一个系统中不正常。

以下是按钮点击的代码 count是全局整数，值为1，在开头

初始化

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

    clickpicfull()

    'PictureBox1.Image.Save("C:\Users\Bulusu\Desktop\Screenshots\" & count & ".jpg", System.Drawing.Imaging.ImageFormat.Jpeg)
    PictureBox1.Image.Save(picspath & "\" & count & ".jpg", System.Drawing.Imaging.ImageFormat.Jpeg)
    count = count + 1

    Me.Controls("label1").Text = "No of Screenshots: " & count - 1
    ' MsgBox(count)

End Sub

以下是获取屏幕截图的代码

Public Sub clickpicfull()
    If count = 1 Then
        Me.Size = New System.Drawing.Size(438, 300)
    End If
    Me.SendToBack()
    Me.Hide()
    Me.Opacity = 0
    Form2.Hide()

    Dim area As Rectangle
    Dim capture As System.Drawing.Bitmap
    Dim graph As Graphics
    area = Screen.PrimaryScreen.Bounds
    capture = New System.Drawing.Bitmap(area.Width, area.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb)
    graph = Graphics.FromImage(capture)
    graph.CopyFromScreen(area.X, area.Y, 0, 0, area.Size, CopyPixelOperation.SourceCopy)

    PictureBox1.Image = capture
    Me.Opacity = 100
    Me.Show()
    Me.BringToFront()
End Sub

Answer 1

感谢@HansPassant，通过更改下面的不透明度值给出了我想要的结果

在设计器中将表单的默认不透明度设置为99并进行交换使用以下

在0到0.99之间的不透明度

Me.Opacity = 0且Me.Opacity = 0.99

`Public Sub clickpicfull()
    ' Me.Hide()                 'solution 1
    'Thread.Sleep(500)          'solution 1
    Me.Opacity = 0              'solution 2
    Form2.Hide()

    Dim area As Rectangle
    Dim capture As System.Drawing.Bitmap
    Dim graph As Graphics
    area = Screen.PrimaryScreen.Bounds
    capture = New System.Drawing.Bitmap(area.Width, area.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb)
    graph = Graphics.FromImage(capture)
    graph.CopyFromScreen(area.X, area.Y, 0, 0, area.Size, CopyPixelOperation.SourceCopy)

    PictureBox1.Image = capture
    Me.Opacity = 0.99           'solution 2
    'Me.Show()                  'solution 1

End Sub`

Answer 2

您需要让系统处理事件。当您在Window类上调用大多数方法时，您可能希望等待事情稳定下来。尝试使用Application.DoEvents添加延迟（请务必阅读文档以了解可能发生的任何问题，例如调用非预期的事件处理程序）。此外，不透明度应介于0.0到1.0之间。 100％不透明设置为1.0。

Public Sub clickpicfull()
If count = 1 Then
    Me.Size = New System.Drawing.Size(438, 300)
End If
Me.SendToBack()
Me.Hide()
Me.Opacity = 0
Form2.Hide()
Application.DoEvents()

Dim area As Rectangle
Dim capture As System.Drawing.Bitmap
Dim graph As Graphics
area = Screen.PrimaryScreen.Bounds
capture = New System.Drawing.Bitmap(area.Width, area.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb)
graph = Graphics.FromImage(capture)
graph.CopyFromScreen(area.X, area.Y, 0, 0, area.Size, CopyPixelOperation.SourceCopy)

PictureBox1.Image = capture
Me.Opacity = 1.0
Me.Show()
Me.BringToFront()

End Sub

在VB.net上截取屏幕截图时，用按钮按下表单

2 个答案: