用VB6.0生成一个支持扩展屏截图的截图工具

下面是一个使用VB6.0编写的支持扩展屏截图的截图工具示例。该程序使用Windows API函数和VB6.0自带控件实现屏幕截图功能，并支持多个显示器。

1. 创建一个新的VB6.0项目，并添加以下控件：一个PictureBox控件，一个CommandButton控件和一个Label控件。

2. 在代码窗口中插入以下代码：

Option Explicit

Private Declare Function GetWindowRect Lib "user32" (ByVal hwnd As Long, lpRect As RECT) As Long
Private Declare Function GetForegroundWindow Lib "user32" () As Long
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 BitBlt Lib "gdi32" (ByVal hDestDC As Long, ByVal x As Long, ByVal y As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal hSrcDC As Long, ByVal xSrc As Long, ByVal ySrc As Long, ByVal dwRop As Long) As Long

Private Type RECT
    Left As Long
    Top As Long
    Right As Long
    Bottom As Long
End Type

Private Sub Command1_Click()
    Dim hWnd As Long, hDC As Long, result As Long
    Dim rect As RECT
    Dim picWidth As Long, picHeight As Long
    
    '获取当前活动窗口的句柄
    hWnd = GetForegroundWindow()
    
    '获取窗口的位置和大小
    result = GetWindowRect(hWnd, rect)
    
    '计算截图的宽度和高度
    picWidth = rect.Right - rect.Left
    picHeight = rect.Bottom - rect.Top
    
    '创建图像对象并绘制截图
    Picture1.AutoRedraw = True
    Picture1.Width = picWidth / Screen.TwipsPerPixelX
    Picture1.Height = picHeight / Screen.TwipsPerPixelY
    hDC = GetDC(hWnd)
    result = BitBlt(Picture1.hDC, 0, 0, picWidth, picHeight, hDC, 0, 0, vbSrcCopy)
    result = ReleaseDC(hWnd, hDC)
    Picture1.AutoRedraw = False
    
    '显示截图的宽度和高度
    Label1.Caption = "Width: " & Picture1.ScaleWidth & " Height: " & Picture1.ScaleHeight
End Sub

3. 在窗体的Load事件中添加以下代码，以将PictureBox控件设置为自动换行和自动大小：

Private Sub Form_Load()
    Picture1.AutoSize = True
    Picture1.BorderStyle = vbBSNone
End Sub

4. 运行程序并单击CommandButton控件来进行截图。截图将显示在PictureBox控件中，并且Label控件将显示截图的宽度和高度。

注意：此示例代码只提供了基本的截图功能，并没有包含保存截图或支持多个显示器的完整代码。如果您需要实现更高级的截图功能，请参考Windows API文档和VB6.0开发文档以获取更多信息。