vb6.0如何获取程序窗口指定坐标的像素值

vb6.0如何获取程序窗口指定坐标的像素值，即使程序窗口最小化，也将获取程序窗口指定坐标的像素值。而不是获取电脑桌面这个坐标的像素值。

基于new Bing的回答：

以下是获取程序窗口指定坐标的像素值的VB6.0代码：

声明API函数

Private Declare Function GetDC Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function ReleaseDC Lib "user32" (ByVal hwnd As Long, ByVal hdc As Long) As Long
Private Declare Function GetPixel Lib "gdi32" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long) As Long

获取程序窗口的句柄

Dim hwnd As Long
hwnd = FindWindow(vbNullString, "程序窗口的标题")

获取程序窗口的设备上下文句柄

Dim hdc As Long
hdc = GetDC(hwnd)

获取指定坐标的像素值

Dim pixel As Long
pixel = GetPixel(hdc, x, y)

释放程序窗口的设备上下文句柄

ReleaseDC hwnd, hdc

完整代码如下：

Private Declare Function GetDC Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function ReleaseDC Lib "user32" (ByVal hwnd As Long, ByVal hdc As Long) As Long
Private Declare Function GetPixel Lib "gdi32" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long) As Long

Private Sub Command1_Click()
    Dim hwnd As Long
    hwnd = FindWindow(vbNullString, "程序窗口的标题")
    If hwnd = 0 Then
        MsgBox "未找到程序窗口"
        Exit Sub
    End If
    
    Dim hdc As Long
    hdc = GetDC(hwnd)
    
    Dim x As Long, y As Long
    x = 100
    y = 100
    Dim pixel As Long
    pixel = GetPixel(hdc, x, y)
    
    ReleaseDC hwnd, hdc
    
    MsgBox "像素值为：" & pixel
End Sub

需要注意的是，如果程序窗口最小化了，可以使用IsIconic函数来判断窗口是否最小化，如果最小化了，可以使用ShowWindow函数将窗口还原到正常状态

用 Windows API 函数 GetPixel

Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Private Declare Function GetDC Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function GetPixel Lib "gdi32" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long) As Long
Private Declare Function ReleaseDC Lib "user32" (ByVal hwnd As Long, ByVal hdc As Long) As Long

Private Sub Command1_Click()
    Dim hwnd As Long
    Dim hdc As Long
    Dim pixelValue As Long
    Dim x As Long, y As Long
    
    '获取窗口句柄
    hwnd = FindWindow(vbNullString, "窗口标题")
    
    '获取设备上下文
    hdc = GetDC(hwnd)
    
    '获取指定坐标的像素值
    x = 100 '指定 x 坐标
    y = 200 '指定 y 坐标
    pixelValue = GetPixel(hdc, x, y)
    
    '释放设备上下文
    ReleaseDC hwnd, hdc
    
    '显示像素值
    MsgBox "坐标 (" & x & ", " & y & ") 的像素值为 " & pixelValue
End Sub

以下内容部分参考ChatGPT模型：

可以使用API函数GetPixel获取窗口指定坐标的像素值。具体步骤如下：

1. 获取窗口句柄：使用FindWindow或FindWindowEx函数获取窗口句柄。

2. 获取设备上下文句柄：使用GetDC函数获取设备上下文句柄。

3. 使用SelectObject函数选择一个位图对象（可以使用CreateCompatibleBitmap创建一个位图对象）。

4. 使用BitBlt函数将窗口画面复制到位图对象中。

5. 使用GetPixel函数获取位图对象指定坐标的像素值。

6. 释放设备上下文句柄和位图对象。

以下是示例代码：

Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As Any, ByVal lpWindowName As Any) As Long
Private Declare Function GetDC Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function CreateCompatibleBitmap Lib "gdi32" (ByVal hdc As Long, ByVal nWidth As Long, ByVal nHeight As Long) As Long
Private Declare Function SelectObject Lib "gdi32" (ByVal hdc As Long, ByVal hObject As Long) As Long
Private Declare Function BitBlt Lib "gdi32" (ByVal hdcDest As Long, ByVal xDest As Long, ByVal yDest As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal hdcSrc As Long, ByVal xSrc As Long, ByVal ySrc As Long, ByVal dwRop As Long) As Long
Private Declare Function GetPixel Lib "gdi32" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long) As Long
Private Declare Function ReleaseDC Lib "user32" (ByVal hwnd As Long, ByVal hdc As Long) As Long

Private Sub Form_Load()
    '获取窗口句柄
    Dim hwnd As Long
    hwnd = FindWindow(vbNullString, "窗口标题")

    '获取设备上下文句柄
    Dim hdcScreen As Long
    hdcScreen = GetDC(hwnd)

    '创建位图对象
    Dim bmp As Long
    bmp = CreateCompatibleBitmap(hdcScreen, Me.ScaleWidth, Me.ScaleHeight)

    '选择位图对象
    Dim hdcBmp As Long
    hdcBmp = CreateCompatibleDC(hdcScreen)
    SelectObject hdcBmp, bmp

    '复制窗口画面到位图对象中
    BitBlt hdcBmp, 0, 0, Me.ScaleWidth, Me.ScaleHeight, hdcScreen, 0, 0, vbSrcCopy

    '获取指定坐标的像素值
    Dim x As Long, y As Long
    x = 100
    y = 100
    Dim pixelColor As Long
    pixelColor = GetPixel(hdcBmp, x, y)

    '释放设备上下文句柄和位图对象
    ReleaseDC hwnd, hdcScreen
    DeleteDC hdcBmp
    DeleteObject bmp

    '显示像素值
    MsgBox "坐标(" & x & "," & y & ")的像素值为：" & pixelColor
End Sub

注意：在最小化状态下，窗口的画面可能无法完全复制到位图对象中，因此获取的像素值可能不准确。

如果我的建议对您有帮助、请点击采纳、祝您生活愉快

• 这个问题的回答你可以参考下: https://ask.csdn.net/questions/357761
• 我还给你找了一篇非常好的博客，你可以看看是否有帮助，链接：VB让窗体图片随着窗体大小而缩放，适合做换肤窗口
• 除此之外, 这篇博客: VB程序设计练习题（一）中的 4.猴子吃桃，递推举法 部分也许能够解决你的问题, 你可以仔细阅读以下内容或跳转源博客中阅读:
  

• （要以上一个本身做铺垫才能求出下一个的值的，如果把i设为循环值，在循环中的i只是它的下标签，在循环中不需要把i当系数，也就是说循环中不出现i）

  

  答案:

  Private Sub Command1_Click()

  x = 1

  Print "第8天的桃子数量是1个"

  For i = 7 To 1 Step -1

        x = (x + 1) * 2         #循环中不需要出现i

        Print "第" & i & "天的桃子数量是" & x & "个"

  Next

  End Sub

  ---

• 您还可以看一下 张景平老师的VB程序设计教程:从入门到精通课程中的 多重窗体小节, 巩固相关知识点
  

以下答案由GPT-3.5大模型与博主波罗歌共同编写：
获取程序窗口指定坐标的像素值，可以通过API函数GetDC和GetPixel实现。

具体实现步骤如下：

1. 获取目标程序窗口的句柄：可以使用API函数FindWindow或FindWindowEx，如果已知窗口标题，则可以使用FindWindow，如果已知窗口类名，则可以使用FindWindowEx。

2. 获取目标程序窗口的设备上下文句柄：使用API函数GetDC获取设备上下文句柄。

3. 使用API函数GetPixel获取指定坐标的像素值。

4. 释放设备上下文句柄：使用API函数ReleaseDC释放设备上下文句柄。

示例代码如下：

Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Private Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" (ByVal hWndParent As Long, ByVal hWndChildAfter As Long, ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Private Declare Function GetDC Lib "user32" (ByVal hWnd As Long) As Long
Private Declare Function GetPixel Lib "gdi32" (ByVal hdc As Long, ByVal X As Long, ByVal Y As Long) As Long
Private Declare Function ReleaseDC Lib "user32" (ByVal hWnd As Long, ByVal hdc As Long) As Long

Private Sub Command1_Click()
    Dim hWnd As Long
    Dim hdc As Long
    Dim pixelVal As Long
    
    hWnd = FindWindow(vbNullString, "目标窗口标题")
    If hWnd = 0 Then
        MsgBox "未找到目标窗口"已黑化的小白         Exit Sub
    End If
    
    hdc = GetDC(hWnd)
    If hdc = 0 Then
        MsgBox "获取设备上下文句柄失败"已黑化的小白         Exit Sub
    End If
    
    '获取指定坐标(100,100)的像素值
    pixelVal = GetPixel(hdc, 100, 100)
    '将像素值转换为RGB值
    Dim red As Byte, green As Byte, blue As Byte
    red = pixelVal Mod 256
    green = (pixelVal \ 256) Mod 256
    blue = (pixelVal \ 65536) Mod 256
    MsgBox "红色分量：" & red & "，绿色分量：" & green & "，蓝色分量：" & blue
    
    ReleaseDC hWnd, hdc
End Sub

需要注意的是，该方法只能获取指定窗口内的像素值，不能获取窗口外的像素值。如果需要获取窗口外的像素值，则需要使用其他方法，例如使用API函数PrintWindow将窗口截图并保存为位图文件，然后再读取位图文件中的像素值。
如果我的回答解决了您的问题，请采纳！