Question

（VB）API 函数 GetCursorPos 的问题？

Private Structure POINTAPI
Dim x As Long
Dim y As Long
End Structure

Private Declare Function GetCursorPos Lib "user32" (ByVal AP As POINTAPI) As Long

Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim a As POINTAPI
GetCursorPos(a)
Bt1.Text = a.x
End Sub

这段代码那里错了？为什么有错误提示：
对 PInvoke 函数“练习!练习.Form1::GetCursorPos”的调用导致堆栈不对称。原因可能是托管的 PInvoke 签名与非托管的目标签名不匹配。请检查 PInvoke 签名的调用约定和参数与非托管的目标签名是否匹配。
我用的是VB 2005，所以你们写的代码会报错

Answer 1

自定义类型的变量在给api传递时必须传址，byval不行。

Answer 2

Private Structure POINTAPI
Dim x As Integer
Dim y As Integer
End Structure

Private Declare Function GetCursorPos Lib "user32" (ByRef AP As POINTAPI) As Integer

Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim a As POINTAPI
GetCursorPos(a)
Bt1.Text = a.x
End Sub

Answer 3

Private Declare Function GetCursorPos Lib "user32" (lpPoint As POINTAPI) As Long

Private Type POINTAPI
x As Long
y As Long
End Type

Private Sub Form_Click()
Dim a As POINTAPI
GetCursorPos a
Bt1.Text =a.x
End Sub

Answer 4

Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Form1_Load()这个过程是你自已写的呢,还是默认的呢?