Java - 窗口图像 [英] Java - Window Image
本文介绍了Java - 窗口图像的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
有没有人知道如何捕获Java中的屏幕截图（不是它自己的屏幕，而是桌面上的任何其他窗口，他们不必须是活动窗口）？这个类似的主题有很多线索，但我还没有找到答案。
Does anyone know how to capture a screen shot in Java (not it's own screen, but any other window on the desktop and they don't necessarily have to be the active window) in Windows? There are a number of threads here on this similar subject, but I have yet to find an answer.
我尝试过使用JNA，但经过几次尝试后卡住了。例如......
I've tried using JNA, but became stuck after a few attempts. For example...
public class Main {
public static void main(String[] args) {
Main m = new Main();
List<WindowInfo> list = m.getWindows();
for (int i=0;i<list.size();i++)
{
WindowInfo info = list.get(i);
System.out.println(info.getTitle());
}
WindowInfo wi = list.get(0);
W32API.HDC hdcSrc = User32.instance.GetWindowDC(wi.getHwnd());
W32API.HDC hdcMemory = Gdi32.instance.CreateCompatibleDC(hdcSrc);
//W32API.HBITMAP hBitmapMemory = Gdi32.instance.CreateCompatibleBitmap(hdcSrc, int width, int height);
int width = wi.getRect().right - wi.getRect().left;
int height = wi.getRect().bottom - wi.getRect().top;
W32API.HBITMAP hBitmapMemory = Gdi32.instance.CreateCompatibleBitmap(hdcSrc, width, height);
W32API.HANDLE hOld = Gdi32.instance.SelectObject(hdcMemory, hBitmapMemory);
Gdi32.instance.BitBlt(hdcMemory, 0, 0, width, height, hdcSrc, width+2, height+2, 0x00CC0020);
/* # now how do we convert to a BufferedImage??? */
// clean up
Gdi32.instance.SelectObject(hdcMemory, hOld);
Gdi32.instance.DeleteDC(hdcMemory);
Gdi32.instance.DeleteObject(hBitmapMemory);
User32.instance.ReleaseDC(wi.getHwnd(), hdcSrc);
}
/**
*
* @return
*/
private List<WindowInfo> getWindows() {
final List<WindowInfo> list = new ArrayList<WindowInfo>();
User32.instance.EnumWindows(new WndEnumProc() {
public boolean callback(int hWnd, int lParam) {
if (User32.instance.IsWindowVisible(hWnd)) {
RECT r = new RECT();
User32.instance.GetWindowRect(hWnd, r);
byte[] buffer = new byte[1024];
User32.instance.GetWindowTextA(hWnd, buffer, buffer.length);
String title = Native.toString(buffer);
if (title!=null&&title.length()>0) {
list.add(new WindowInfo(hWnd, r, title));
}
}
return true;
}
}, 0);
Collections.sort(list, new Comparator<WindowInfo>() {
public int compare(WindowInfo o1, WindowInfo o2) {
int i1 = (o1.getTitle()!=null&&o1.getTitle().length()>0?o1.getTitle():" ").charAt(0);
int i2 = (o2.getTitle()!=null&&o2.getTitle().length()>0?o2.getTitle():" ").charAt(0);
return i1 - i2;
}
});
return list;
}
}
我也试过相当于PrintWindow（ ）API ...
I've also tried the equivalent of "PrintWindow()" API...
Graphics g = form.CreateGraphics();
Bitmap bmp = new Bitmap(form.Size.Width, form.Size.Height, g);
Graphics memoryGraphics = Graphics.FromImage(bmp);
IntPtr dc = memoryGraphics.GetHdc();
bool success = PrintWindow(form.Handle, dc, 0);
memoryGraphics.ReleaseHdc(dc);
// bmp now contains the screenshot
或者我是否必须使用JNI或任何其他工具？
Or do I have to use JNI, or any other tool?
推荐答案
这是一个有效的例子。
该应用程序被捕获不能被最小化，但它不需要有焦点或在顶部（即可见）。
The application being captured can't be minimized but it doesn't need to have focus or be on top (i.e. visible).
相关C＃线程中提供的代码， MSDN文章捕获图像和jmemoryeditorw提供必要的部分。
The code provided in the related C# thread, the MSDN article Capturing an Image and jmemoryeditorw provided the necessary pieces.
代码使用GetDC和GetClientRect来捕获窗口的客户区域。如果你想捕获包括窗口装饰在内的整个窗口，可以用GetWindowDC和GetWindowRect替换它们。
The code uses GetDC and GetClientRect to capture the client area of the window. They can be replaced by GetWindowDC and GetWindowRect if you want to capture the whole window including window decorations.
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import javax.swing.JFrame;
import jna.extra.GDI32Extra;
import jna.extra.User32Extra;
import jna.extra.WinGDIExtra;
import com.sun.jna.Memory;
import com.sun.jna.platform.win32.GDI32;
import com.sun.jna.platform.win32.User32;
import com.sun.jna.platform.win32.WinDef.HBITMAP;
import com.sun.jna.platform.win32.WinDef.HDC;
import com.sun.jna.platform.win32.WinDef.HWND;
import com.sun.jna.platform.win32.WinDef.RECT;
import com.sun.jna.platform.win32.WinGDI;
import com.sun.jna.platform.win32.WinGDI.BITMAPINFO;
import com.sun.jna.platform.win32.WinNT.HANDLE;
public class Paint extends JFrame {
public BufferedImage capture(HWND hWnd) {
HDC hdcWindow = User32.INSTANCE.GetDC(hWnd);
HDC hdcMemDC = GDI32.INSTANCE.CreateCompatibleDC(hdcWindow);
RECT bounds = new RECT();
User32Extra.INSTANCE.GetClientRect(hWnd, bounds);
int width = bounds.right - bounds.left;
int height = bounds.bottom - bounds.top;
HBITMAP hBitmap = GDI32.INSTANCE.CreateCompatibleBitmap(hdcWindow, width, height);
HANDLE hOld = GDI32.INSTANCE.SelectObject(hdcMemDC, hBitmap);
GDI32Extra.INSTANCE.BitBlt(hdcMemDC, 0, 0, width, height, hdcWindow, 0, 0, WinGDIExtra.SRCCOPY);
GDI32.INSTANCE.SelectObject(hdcMemDC, hOld);
GDI32.INSTANCE.DeleteDC(hdcMemDC);
BITMAPINFO bmi = new BITMAPINFO();
bmi.bmiHeader.biWidth = width;
bmi.bmiHeader.biHeight = -height;
bmi.bmiHeader.biPlanes = 1;
bmi.bmiHeader.biBitCount = 32;
bmi.bmiHeader.biCompression = WinGDI.BI_RGB;
Memory buffer = new Memory(width * height * 4);
GDI32.INSTANCE.GetDIBits(hdcWindow, hBitmap, 0, height, buffer, bmi, WinGDI.DIB_RGB_COLORS);
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
image.setRGB(0, 0, width, height, buffer.getIntArray(0, width * height), 0, width);
GDI32.INSTANCE.DeleteObject(hBitmap);
User32.INSTANCE.ReleaseDC(hWnd, hdcWindow);
return image;
}
public static void main(String[] args) {
new Paint();
}
BufferedImage image;
public Paint() {
HWND hWnd = User32.INSTANCE.FindWindow(null, "Untitled - Notepad");
this.image = capture(hWnd);
setDefaultCloseOperation(EXIT_ON_CLOSE);
pack();
setExtendedState(MAXIMIZED_BOTH);
setVisible(true);
}
@Override
public void paint(Graphics g) {
super.paint(g);
g.drawImage(image, 20, 40, null);
}
}
我必须定义一些未包含在platform.jar中的额外函数（可以在JNA网站上找到）。
I had to define some extra functions that weren't included in platform.jar (which can be found on the JNA website).
package jna.extra;
import com.sun.jna.Native;
import com.sun.jna.platform.win32.GDI32;
import com.sun.jna.platform.win32.WinDef.DWORD;
import com.sun.jna.platform.win32.WinDef.HDC;
import com.sun.jna.win32.W32APIOptions;
public interface GDI32Extra extends GDI32 {
GDI32Extra INSTANCE = (GDI32Extra) Native.loadLibrary("gdi32", GDI32Extra.class, W32APIOptions.DEFAULT_OPTIONS);
public boolean BitBlt(HDC hObject, int nXDest, int nYDest, int nWidth, int nHeight, HDC hObjectSource, int nXSrc, int nYSrc, DWORD dwRop);
}
package jna.extra;
import com.sun.jna.Native;
import com.sun.jna.platform.win32.User32;
import com.sun.jna.platform.win32.WinDef.HDC;
import com.sun.jna.platform.win32.WinDef.HWND;
import com.sun.jna.platform.win32.WinDef.RECT;
import com.sun.jna.win32.W32APIOptions;
public interface User32Extra extends User32 {
User32Extra INSTANCE = (User32Extra) Native.loadLibrary("user32", User32Extra.class, W32APIOptions.DEFAULT_OPTIONS);
public HDC GetWindowDC(HWND hWnd);
public boolean GetClientRect(HWND hWnd, RECT rect);
}
package jna.extra;
import com.sun.jna.platform.win32.WinDef.DWORD;
import com.sun.jna.platform.win32.WinGDI;
public interface WinGDIExtra extends WinGDI {
public DWORD SRCCOPY = new DWORD(0x00CC0020);
}
这篇关于Java - 窗口图像的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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