打印 Panel 内容的图像,不包括任何外部重叠 Window
Print an image of the content of a Panel excluding any external overlapping Window
我有一些问题。
我在表单中有一个面板和一个图片框。
我想打开一个 Windows 应用程序(例如记事本)并将其添加到面板。
然后我想在 PictureBox 中显示面板内容的图像:
我的代码:
[DllImport("user32.dll", SetLastError = true)]
private static extern long SetParent(IntPtr hWndChild, IntPtr hWndNewParent);
[DllImport("user32.dll", SetLastError = true)]
private static extern long SetWindowPos(IntPtr hwnd, long hWndInsertAfter, long x, long y, long cx, long cy, long wFlags);
[DllImport("user32.dll", SetLastError = true)]
private static extern bool MoveWindow(IntPtr hwnd, int x, int y, int cx, int cy, bool repaint);
IntPtr appWin1;
private void Notepad_Button_Click(object sender, EventArgs e)
{
ProcessStartInfo ps1 = new ProcessStartInfo(@"notepad.exe");
ps1.WindowStyle = ProcessWindowStyle.Minimized;
Process p1 = Process.Start(ps1);
System.Threading.Thread.Sleep(5000); // Allow the process to open it's window
appWin1 = p1.MainWindowHandle;
// Put it into this form
SetParent(appWin1, this.panel1.Handle);
}
private void timer1_Tick(object sender, EventArgs e)
{
Bitmap bm = new Bitmap(panel1.Width, panel1.Height);
Graphics g = Graphics.FromImage(bm);
g.CopyFromScreen(0, 0, 0, 0, bm.Size);
pictureBox1.Image = bm;
}
private void Form5_Load(object sender, EventArgs e)
{
}
private void panel1_Paint(object sender, PaintEventArgs e)
{
}
private void timer2_Tick(object sender, EventArgs e)
{
MoveWindow(appWin1, 0, 0, this.panel1.Width, this.panel1.Height, true);
}
private void pictureBox1_Click(object sender, EventArgs e)
{
}
运行 这段代码:
问题是这样的:我只想获取面板内部的内容,但是在我的面板前面移动的任何其他 Window 都包含在 PictureBox 中显示的位图中:
[}3
如图所示,外部页面放在panel1
时,也会出现在pictureBox1
(图中红框)
我只希望记事本出现在 pictureBox1
中,无论 Window 悬停在 panel1
.
上
由于您想将 Panel 的内容呈现为 Bitmap - 它正在托管外部应用程序 - 您不能使用 Control.DrawToBitmap():托管应用程序的内容,父级调用 SetParent()
,赢得' 被打印出来。
由于您还想从渲染中排除可能悬停在面板上的任何其他 Window,您可以使用 PrintWindow 函数,传递面板的父窗体的句柄。
表单将收到 WM_PRINT
或 WM_PRINTCLIENT
消息,并将自身打印到指定的设备上下文:在本例中,从位图生成。
这不是屏幕截图:Window 将自身及其内容绘制到 DC,因此其他 Windows 是否悬停/部分完全重叠并不重要,结果是一样的。
我正在使用 DwmGetWindowAttribute,设置 DWMWA_EXTENDED_FRAME_BOUNDS
,以获得要打印的 Window 的边界。它可能看起来 冗余,但是,如果您的应用不是 DpiAware 并且您有一个高 Dpi 屏幕,那么在这种情况下它会显得不那么 冗余 .最好有它,IMO。
此功能比 GetWindowRect
或 GetClientRect
更 可靠 ,它将 return 在可变 DPI 上下文中纠正措施。
您不能将子 Window 的句柄传递给此函数,所以我使用父窗体的句柄生成位图,然后 select 面板所在的部分位于。这取决于:
[ParentForm].RectangleToClient([Child].RectangleToScreen([Child].ClientRectangle))
启动进程和父记事本的Window到面板控件:
private void Notepad_Button_Click(object sender, EventArgs e)
{
var psi = new ProcessStartInfo(@"notepad.exe") { WindowStyle = ProcessWindowStyle.Minimized };
using (var p = Process.Start(psi)) {
p.WaitForInputIdle();
var handle = p.MainWindowHandle;
if (handle != IntPtr.Zero) {
SetParent(handle, panel1.Handle);
MoveWindow(handle, 0, 0, panel1.Width, panel1.Height, true);
}
}
}
现在,只要您想将面板所在的表单部分呈现为位图,请调用 RenderWindow 并获取您感兴趣的部分:面板的 ClientRectangle。
using (var image = RenderWindow(this.Handle, true, false)) {
if (image is null) return;
if (WindowState == FormWindowState.Minimized) return;
var panelRect = RectangleToClient(panel1.RectangleToScreen(panel1.ClientRectangle));
pictureBox1.Image?.Dispose();
pictureBox1.Image = image.Clone(panelRect, PixelFormat.Format32bppArgb);
}
// [...]
public static Bitmap RenderWindow(IntPtr hWnd, bool clientAreaOnly, bool tryGetFullContent = false)
{
var printOption = clientAreaOnly ? PrintWindowOptions.PW_CLIENTONLY : PrintWindowOptions.PW_DEFAULT;
printOption = tryGetFullContent ? PrintWindowOptions.PW_RENDERFULLCONTENT : printOption;
var hResult = DwmGetWindowAttribute(hWnd, DWMWINDOWATTRIBUTE.DWMWA_EXTENDED_FRAME_BOUNDS, out Rectangle dwmRect, Marshal.SizeOf<Rectangle>());
if (hResult < 0) {
Marshal.ThrowExceptionForHR(hResult);
return null;
}
if (dwmRect.Width <= 0 || dwmRect.Height <= 0) return null;
var bmp = new Bitmap(dwmRect.Width, dwmRect.Height);
using (var g = Graphics.FromImage(bmp)) {
var hDC = g.GetHdc();
try {
var success = PrintWindow(hWnd, hDC, printOption);
if (!success) {
// Failed, see what happened
var win32Error = Marshal.GetLastWin32Error();
return null;
}
return bmp;
}
finally {
g.ReleaseHdc(hDC);
}
}
}
Win32 声明:
[DllImport("user32.dll", SetLastError = true)]
static extern IntPtr SetParent(IntPtr hWndChild, IntPtr hWndNewParent);
[DllImport("user32.dll", SetLastError = true)]
static extern bool MoveWindow(IntPtr hWnd, int x, int y, int nWidth, int nHeight, bool bRepaint);
public enum PrintWindowOptions : uint
{
PW_DEFAULT = 0,
PW_CLIENTONLY = 1,
PW_RENDERFULLCONTENT = 2 // Undocumented. Use, e.g., with a WebBrowser
}
[DllImport("user32.dll", SetLastError = true)]
static extern internal bool PrintWindow(IntPtr hwnd, IntPtr hDC, PrintWindowOptions nFlags);
public enum DWMWINDOWATTRIBUTE : uint
{
DWMWA_NCRENDERING_ENABLED = 1, // [get] Is non-client rendering enabled/disabled
DWMWA_NCRENDERING_POLICY, // [set] DWMNCRENDERINGPOLICY - Non-client rendering policy - Enable or disable non-client rendering
DWMWA_TRANSITIONS_FORCEDISABLED, // [set] Potentially enable/forcibly disable transitions
DWMWA_ALLOW_NCPAINT, // [set] Allow contents rendered In the non-client area To be visible On the DWM-drawn frame.
DWMWA_CAPTION_BUTTON_BOUNDS, // [get] Bounds Of the caption button area In window-relative space.
DWMWA_NONCLIENT_RTL_LAYOUT, // [set] Is non-client content RTL mirrored
DWMWA_FORCE_ICONIC_REPRESENTATION, // [set] Force this window To display iconic thumbnails.
DWMWA_FLIP3D_POLICY, // [set] Designates how Flip3D will treat the window.
DWMWA_EXTENDED_FRAME_BOUNDS, // [get] Gets the extended frame bounds rectangle In screen space
DWMWA_HAS_ICONIC_BITMAP, // [set] Indicates an available bitmap When there Is no better thumbnail representation.
DWMWA_DISALLOW_PEEK, // [set] Don't invoke Peek on the window.
DWMWA_EXCLUDED_FROM_PEEK, // [set] LivePreview exclusion information
DWMWA_CLOAK, // [set] Cloak Or uncloak the window
DWMWA_CLOAKED, // [get] Gets the cloaked state Of the window. Returns a DWMCLOACKEDREASON object
DWMWA_FREEZE_REPRESENTATION, // [set] BOOL, Force this window To freeze the thumbnail without live update
PlaceHolder1,
PlaceHolder2,
PlaceHolder3,
DWMWA_ACCENTPOLICY = 19
}
[DllImport("dwmapi.dll", SetLastError = true)]
static extern internal int DwmGetWindowAttribute(IntPtr hwnd, DWMWINDOWATTRIBUTE dwAttribute, out Rectangle pvAttribute, int cbAttribute);
我有一些问题。
我在表单中有一个面板和一个图片框。
我想打开一个 Windows 应用程序(例如记事本)并将其添加到面板。
然后我想在 PictureBox 中显示面板内容的图像:
我的代码:
[DllImport("user32.dll", SetLastError = true)]
private static extern long SetParent(IntPtr hWndChild, IntPtr hWndNewParent);
[DllImport("user32.dll", SetLastError = true)]
private static extern long SetWindowPos(IntPtr hwnd, long hWndInsertAfter, long x, long y, long cx, long cy, long wFlags);
[DllImport("user32.dll", SetLastError = true)]
private static extern bool MoveWindow(IntPtr hwnd, int x, int y, int cx, int cy, bool repaint);
IntPtr appWin1;
private void Notepad_Button_Click(object sender, EventArgs e)
{
ProcessStartInfo ps1 = new ProcessStartInfo(@"notepad.exe");
ps1.WindowStyle = ProcessWindowStyle.Minimized;
Process p1 = Process.Start(ps1);
System.Threading.Thread.Sleep(5000); // Allow the process to open it's window
appWin1 = p1.MainWindowHandle;
// Put it into this form
SetParent(appWin1, this.panel1.Handle);
}
private void timer1_Tick(object sender, EventArgs e)
{
Bitmap bm = new Bitmap(panel1.Width, panel1.Height);
Graphics g = Graphics.FromImage(bm);
g.CopyFromScreen(0, 0, 0, 0, bm.Size);
pictureBox1.Image = bm;
}
private void Form5_Load(object sender, EventArgs e)
{
}
private void panel1_Paint(object sender, PaintEventArgs e)
{
}
private void timer2_Tick(object sender, EventArgs e)
{
MoveWindow(appWin1, 0, 0, this.panel1.Width, this.panel1.Height, true);
}
private void pictureBox1_Click(object sender, EventArgs e)
{
}
运行 这段代码:
问题是这样的:我只想获取面板内部的内容,但是在我的面板前面移动的任何其他 Window 都包含在 PictureBox 中显示的位图中:
[
如图所示,外部页面放在panel1
时,也会出现在pictureBox1
(图中红框)
我只希望记事本出现在 pictureBox1
中,无论 Window 悬停在 panel1
.
由于您想将 Panel 的内容呈现为 Bitmap - 它正在托管外部应用程序 - 您不能使用 Control.DrawToBitmap():托管应用程序的内容,父级调用 SetParent()
,赢得' 被打印出来。
由于您还想从渲染中排除可能悬停在面板上的任何其他 Window,您可以使用 PrintWindow 函数,传递面板的父窗体的句柄。
表单将收到 WM_PRINT
或 WM_PRINTCLIENT
消息,并将自身打印到指定的设备上下文:在本例中,从位图生成。
这不是屏幕截图:Window 将自身及其内容绘制到 DC,因此其他 Windows 是否悬停/部分完全重叠并不重要,结果是一样的。
我正在使用 DwmGetWindowAttribute,设置 DWMWA_EXTENDED_FRAME_BOUNDS
,以获得要打印的 Window 的边界。它可能看起来 冗余,但是,如果您的应用不是 DpiAware 并且您有一个高 Dpi 屏幕,那么在这种情况下它会显得不那么 冗余 .最好有它,IMO。
此功能比 GetWindowRect
或 GetClientRect
更 可靠 ,它将 return 在可变 DPI 上下文中纠正措施。
您不能将子 Window 的句柄传递给此函数,所以我使用父窗体的句柄生成位图,然后 select 面板所在的部分位于。这取决于:
[ParentForm].RectangleToClient([Child].RectangleToScreen([Child].ClientRectangle))
启动进程和父记事本的Window到面板控件:
private void Notepad_Button_Click(object sender, EventArgs e)
{
var psi = new ProcessStartInfo(@"notepad.exe") { WindowStyle = ProcessWindowStyle.Minimized };
using (var p = Process.Start(psi)) {
p.WaitForInputIdle();
var handle = p.MainWindowHandle;
if (handle != IntPtr.Zero) {
SetParent(handle, panel1.Handle);
MoveWindow(handle, 0, 0, panel1.Width, panel1.Height, true);
}
}
}
现在,只要您想将面板所在的表单部分呈现为位图,请调用 RenderWindow 并获取您感兴趣的部分:面板的 ClientRectangle。
using (var image = RenderWindow(this.Handle, true, false)) {
if (image is null) return;
if (WindowState == FormWindowState.Minimized) return;
var panelRect = RectangleToClient(panel1.RectangleToScreen(panel1.ClientRectangle));
pictureBox1.Image?.Dispose();
pictureBox1.Image = image.Clone(panelRect, PixelFormat.Format32bppArgb);
}
// [...]
public static Bitmap RenderWindow(IntPtr hWnd, bool clientAreaOnly, bool tryGetFullContent = false)
{
var printOption = clientAreaOnly ? PrintWindowOptions.PW_CLIENTONLY : PrintWindowOptions.PW_DEFAULT;
printOption = tryGetFullContent ? PrintWindowOptions.PW_RENDERFULLCONTENT : printOption;
var hResult = DwmGetWindowAttribute(hWnd, DWMWINDOWATTRIBUTE.DWMWA_EXTENDED_FRAME_BOUNDS, out Rectangle dwmRect, Marshal.SizeOf<Rectangle>());
if (hResult < 0) {
Marshal.ThrowExceptionForHR(hResult);
return null;
}
if (dwmRect.Width <= 0 || dwmRect.Height <= 0) return null;
var bmp = new Bitmap(dwmRect.Width, dwmRect.Height);
using (var g = Graphics.FromImage(bmp)) {
var hDC = g.GetHdc();
try {
var success = PrintWindow(hWnd, hDC, printOption);
if (!success) {
// Failed, see what happened
var win32Error = Marshal.GetLastWin32Error();
return null;
}
return bmp;
}
finally {
g.ReleaseHdc(hDC);
}
}
}
Win32 声明:
[DllImport("user32.dll", SetLastError = true)]
static extern IntPtr SetParent(IntPtr hWndChild, IntPtr hWndNewParent);
[DllImport("user32.dll", SetLastError = true)]
static extern bool MoveWindow(IntPtr hWnd, int x, int y, int nWidth, int nHeight, bool bRepaint);
public enum PrintWindowOptions : uint
{
PW_DEFAULT = 0,
PW_CLIENTONLY = 1,
PW_RENDERFULLCONTENT = 2 // Undocumented. Use, e.g., with a WebBrowser
}
[DllImport("user32.dll", SetLastError = true)]
static extern internal bool PrintWindow(IntPtr hwnd, IntPtr hDC, PrintWindowOptions nFlags);
public enum DWMWINDOWATTRIBUTE : uint
{
DWMWA_NCRENDERING_ENABLED = 1, // [get] Is non-client rendering enabled/disabled
DWMWA_NCRENDERING_POLICY, // [set] DWMNCRENDERINGPOLICY - Non-client rendering policy - Enable or disable non-client rendering
DWMWA_TRANSITIONS_FORCEDISABLED, // [set] Potentially enable/forcibly disable transitions
DWMWA_ALLOW_NCPAINT, // [set] Allow contents rendered In the non-client area To be visible On the DWM-drawn frame.
DWMWA_CAPTION_BUTTON_BOUNDS, // [get] Bounds Of the caption button area In window-relative space.
DWMWA_NONCLIENT_RTL_LAYOUT, // [set] Is non-client content RTL mirrored
DWMWA_FORCE_ICONIC_REPRESENTATION, // [set] Force this window To display iconic thumbnails.
DWMWA_FLIP3D_POLICY, // [set] Designates how Flip3D will treat the window.
DWMWA_EXTENDED_FRAME_BOUNDS, // [get] Gets the extended frame bounds rectangle In screen space
DWMWA_HAS_ICONIC_BITMAP, // [set] Indicates an available bitmap When there Is no better thumbnail representation.
DWMWA_DISALLOW_PEEK, // [set] Don't invoke Peek on the window.
DWMWA_EXCLUDED_FROM_PEEK, // [set] LivePreview exclusion information
DWMWA_CLOAK, // [set] Cloak Or uncloak the window
DWMWA_CLOAKED, // [get] Gets the cloaked state Of the window. Returns a DWMCLOACKEDREASON object
DWMWA_FREEZE_REPRESENTATION, // [set] BOOL, Force this window To freeze the thumbnail without live update
PlaceHolder1,
PlaceHolder2,
PlaceHolder3,
DWMWA_ACCENTPOLICY = 19
}
[DllImport("dwmapi.dll", SetLastError = true)]
static extern internal int DwmGetWindowAttribute(IntPtr hwnd, DWMWINDOWATTRIBUTE dwAttribute, out Rectangle pvAttribute, int cbAttribute);