Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
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Static f As Boolean = False
If Not f Then
f = True
Button2.Hide()
Button3.Show()
End If
End Sub
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
Static f As Boolean = False
If Not f Then
f = True
Button2.Show()
Button3.Hide()
End If
End Sub
这么难的问题才5分？给你思路：VB.NET改变鼠标形状的唯一方法就是加载图片，但是因为你要求“横向和纵向都到达PictureBox的边界”，也就是说，这个图片必须跟着鼠标移动而变化，显然这是无法做到的。
因此，可以先将鼠标指针隐藏，然后根据鼠标的当前位置，在PictureBox中画十字线，鼠标移动后，将前面画的线擦除，然后在新位置重新画。
为了不擦除PictureBox中已有的图像，在画十字线之前，先保存十字线所覆盖像素点的值，擦除的时候，恢复这些值就可以了。
几乎找不到真正VB.NET的api，都是自己将VB的api改成VB.NET的api，我的理解是声明中对应输入是H的地方保留Long，其他的Long改成Integer，既然VB.NET连MSDN都找不到较全的api说明，不保证api的用法在VB.NET其他版本中适用。
给你个好玩的例子，包括鼠标的隐藏（Ctrl_↓）、显示（Ctrl_↑），移动、点击
在Form1上放上2个TextBox，其中TextBox1.Multiline = True，并且面积大些，2个Button，运行后在TextBox1中点击一下会记录位置，移开鼠标，点击移动或点击Button，可模拟在TextBox1中的点击
Public Class Form1
Public My_MousePosition As Point
'模拟鼠标移动、点击
Declare Sub mouse_event Lib "user32" (ByVal dwFlags As Long, ByVal dx As Integer, ByVal dy As Integer, ByVal cButtons As Long, ByVal dwExtraInfo As Long)
'定义光标的位置
Declare Function SetCursorPos Lib "user32" Alias "SetCursorPos" (ByVal x As Integer, ByVal y As Integer) As Integer
'鼠标的隐藏
Declare Function ShowCursor Lib "user32" Alias "ShowCursor" (ByVal bShow As Integer) As Integer
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
TextBox1.Multiline = True
Button1.Text = "点击"
Button2.Text = "移动"
Me.KeyPreview = True
End Sub
Private Sub Form1_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles Me.KeyDown
If e.Control And e.KeyCode = Keys.Down Then ShowCursor(0)
If e.Control And e.KeyCode = Keys.Up Then ShowCursor(1)
End Sub
Private Sub Form1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseMove
TextBox2.Text = MousePosition.X " " MousePosition.Y
End Sub
Private Sub TextBox1_MouseClick(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles TextBox1.MouseClick
My_MousePosition = MousePosition
TextBox1.Text = My_MousePosition.X " " My_MousePosition.Y vbCrLf
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
SetCursorPos(My_MousePosition.X, My_MousePosition.Y)
mouse_event(H2, 0, 0, 0, 0)
mouse_event(H4, 0, 0, 0, 0)
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
SetCursorPos(My_MousePosition.X, My_MousePosition.Y)
End Sub
End Class
其中
mouse_event Lib "user32" (ByVal dwFlags As Long
的dwFlags的代码是
Const MOUSEEVENTF_LEFTDOWN = H2
Const MOUSEEVENTF_LEFTUP = H4
Const MOUSEEVENTF_MIDDLEDOWN = H20
Const MOUSEEVENTF_MIDDLEUP = H40
Const MOUSEEVENTF_MOVE = H1
Const MOUSEEVENTF_ABSOLUTE = H8000
Const MOUSEEVENTF_RIGHTDOWN = H8
Const MOUSEEVENTF_RIGHTUP = H10
VB.net可以调用DLL吗?如果可以的话,你用VB6.0编写一个DLL给VB.NET调用就行了