feat: 修改代码风格，优化截图方法 (#94)

* feat: 修改代码风格，优化截图方法

* fix: 修复hdc释放错误问题

* chore: update version

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "xcap"
-version = "0.0.1"
+version = "0.0.2"
 edition = "2021"
 description = "A cross-platform screen capture library"
 license = "Apache-2.0"

examples/monitor_capture.rs

@@ -17,7 +17,7 @@ fn main() {
         let image = monitor.capture_image().unwrap();
 
         image
-            .save(format!("monitor-{}.png", normalized(monitor.name())))
+            .save(format!("target/monitor-{}.png", normalized(monitor.name())))
             .unwrap();
     }
 

src/utils/image.rs

@@ -46,10 +46,10 @@ mod tests {
 
     #[test]
     fn bgra() {
-        let image = bgra_to_rgba_image(2, 1, vec![1, 2, 3, 4, 255, 254, 253, 252]).unwrap();
+        let image = bgra_to_rgba_image(2, 1, vec![1, 2, 3, 255, 255, 254, 253, 255]).unwrap();
         assert_eq!(
             image,
-            RgbaImage::from_vec(2, 1, vec![3, 2, 1, 4, 253, 254, 255, 252]).unwrap()
+            RgbaImage::from_vec(2, 1, vec![3, 2, 1, 255, 253, 254, 255, 255]).unwrap()
         );
     }
 

src/windows/boxed.rs

@@ -1,35 +1,41 @@
 use std::{ops::Deref, ptr};
 use windows::{
     core::PCWSTR,
-    Win32::Graphics::Gdi::{CreateDCW, DeleteDC, DeleteObject, GetWindowDC, HBITMAP, HDC},
+    Win32::{
+        Foundation::HWND,
+        Graphics::Gdi::{CreateDCW, DeleteDC, DeleteObject, GetWindowDC, ReleaseDC, HBITMAP, HDC},
+    },
 };
-use windows::Win32::Foundation::HWND;
-use windows::Win32::Graphics::Gdi::{GetDC, ReleaseDC};
-use windows::Win32::UI::WindowsAndMessaging::GetDesktopWindow;
-use crate::{XCapError, XCapResult};
 
-use super::{impl_monitor::ImplMonitor, impl_window::ImplWindow};
-
-pub(crate) struct BoxHDC(HDC);
+pub(super) struct BoxHDC {
+    hdc: HDC,
+    hwnd: Option<HWND>,
+}
 
 impl Deref for BoxHDC {
     type Target = HDC;
     fn deref(&self) -> &Self::Target {
-        &self.0
+        &self.hdc
     }
 }
 
 impl Drop for BoxHDC {
     fn drop(&mut self) {
+        // ReleaseDC 与 DeleteDC 的区别
+        // https://learn.microsoft.com/zh-cn/windows/win32/api/winuser/nf-winuser-releasedc
         unsafe {
-            DeleteDC(self.0);
+            if let Some(hwnd) = self.hwnd {
+                ReleaseDC(hwnd, self.hdc);
+            } else {
+                DeleteDC(self.hdc);
+            }
         };
     }
 }
 
 impl BoxHDC {
-    pub fn new(hdc: HDC) -> Self {
-        BoxHDC(hdc)
+    pub fn new(hdc: HDC, hwnd: Option<HWND>) -> Self {
+        BoxHDC { hdc, hwnd }
     }
 }
 
@@ -46,25 +52,21 @@ impl From<&[u16; 32]> for BoxHDC {
             )
         };
 
-        BoxHDC::new(hdc)
-    }
-}
-
-impl From<&ImplMonitor> for BoxHDC {
-    fn from(impl_monitor: &ImplMonitor) -> Self {
-        BoxHDC::from(&impl_monitor.monitor_info_ex_w.szDevice)
+        BoxHDC::new(hdc, None)
     }
 }
 
-impl From<&ImplWindow> for BoxHDC {
-    fn from(impl_window: &ImplWindow) -> Self {
-        let hdc = unsafe { GetWindowDC(impl_window.hwnd) };
+impl From<HWND> for BoxHDC {
+    fn from(hwnd: HWND) -> Self {
+        // GetWindowDC vs GetDC, GetDC 不会绘制窗口边框
+        // https://learn.microsoft.com/zh-cn/windows/win32/api/winuser/nf-winuser-getwindowdc
+        let hdc = unsafe { GetWindowDC(hwnd) };
 
-        BoxHDC::new(hdc)
+        BoxHDC::new(hdc, Some(hwnd))
     }
 }
 
-pub(crate) struct BoxHBITMAP(HBITMAP);
+pub(super) struct BoxHBITMAP(HBITMAP);
 
 impl Deref for BoxHBITMAP {
     type Target = HBITMAP;
@@ -75,6 +77,7 @@ impl Deref for BoxHBITMAP {
 
 impl Drop for BoxHBITMAP {
     fn drop(&mut self) {
+        // https://learn.microsoft.com/zh-cn/windows/win32/api/wingdi/nf-wingdi-createcompatiblebitmap
         unsafe {
             DeleteObject(self.0);
         };
@@ -86,36 +89,3 @@ impl BoxHBITMAP {
         BoxHBITMAP(h_bitmap)
     }
 }
-
-pub(crate) struct BoxMonitorHDC {
-    hwnd: HWND,
-    hdc: HDC,
-}
-impl Deref for BoxMonitorHDC {
-    type Target = HDC;
-    fn deref(&self) -> &Self::Target {
-        &self.hdc
-    }
-}
-
-impl Drop for BoxMonitorHDC {
-    fn drop(&mut self) {
-        unsafe {
-            ReleaseDC(self.hwnd, self.hdc);
-        };
-    }
-}
-
-impl BoxMonitorHDC {
-    pub unsafe  fn new() -> XCapResult<BoxMonitorHDC> {
-        let hwnd = GetDesktopWindow();
-        let hdc = GetDC(hwnd);
-        if hdc.is_invalid() {
-            return Err(XCapError::new("GetDC is failed"))
-        }
-        Ok(BoxMonitorHDC{
-            hwnd,
-            hdc,
-        })
-    }
-}

src/windows/capture.rs

@@ -1,25 +1,21 @@
 use image::RgbaImage;
 use std::mem;
 use windows::Win32::{
+    Foundation::HWND,
     Graphics::Gdi::{
         BitBlt, CreateCompatibleBitmap, CreateCompatibleDC, GetDIBits, SelectObject, BITMAPINFO,
         BITMAPINFOHEADER, DIB_RGB_COLORS, RGBQUAD, SRCCOPY,
     },
     Storage::Xps::{PrintWindow, PRINT_WINDOW_FLAGS, PW_CLIENTONLY},
-    UI::WindowsAndMessaging::PW_RENDERFULLCONTENT,
+    UI::WindowsAndMessaging::{GetDesktopWindow, PW_RENDERFULLCONTENT},
 };
 
 use crate::{
     error::{XCapError, XCapResult},
     utils::image::bgra_to_rgba_image,
 };
-use crate::platform::boxed::BoxMonitorHDC;
 
-use super::{
-    boxed::{BoxHBITMAP, BoxHDC},
-    impl_monitor::ImplMonitor,
-    impl_window::ImplWindow,
-};
+use super::boxed::{BoxHBITMAP, BoxHDC};
 
 fn to_rgba_image(
     box_hdc_mem: BoxHDC,
@@ -68,33 +64,33 @@ fn to_rgba_image(
 }
 
 #[allow(unused)]
-pub fn capture_monitor(
-    impl_monitor: &ImplMonitor,
-    x: i32,
-    y: i32,
-    width: i32,
-    height: i32,
-) -> XCapResult<RgbaImage> {
+pub fn capture_monitor(x: i32, y: i32, width: i32, height: i32) -> XCapResult<RgbaImage> {
     unsafe {
-        let box_hdc_monitor = BoxMonitorHDC::new()?;
-
-        // 内存中的HDC
-        let box_hdc_mem = BoxHDC::new(CreateCompatibleDC(*box_hdc_monitor));
-        let box_h_bitmap = BoxHBITMAP::new(CreateCompatibleBitmap(*box_hdc_monitor, width, height));
+        let hwnd = GetDesktopWindow();
+        let box_hdc_desktop_window = BoxHDC::from(hwnd);
+
+        // 内存中的HDC，使用 DeleteDC 函数释放
+        // https://learn.microsoft.com/zh-cn/windows/win32/api/wingdi/nf-wingdi-createcompatibledc
+        let box_hdc_mem = BoxHDC::new(CreateCompatibleDC(*box_hdc_desktop_window), None);
+        let box_h_bitmap = BoxHBITMAP::new(CreateCompatibleBitmap(
+            *box_hdc_desktop_window,
+            width,
+            height,
+        ));
 
         // 使用SelectObject函数将这个位图选择到DC中
         SelectObject(*box_hdc_mem, *box_h_bitmap);
 
         // 拷贝原始图像到内存
-        // 咋合理不需要i缩放图片，所以直接使用BitBlt
+        // 这里不需要缩放图片，所以直接使用BitBlt
         // 如需要缩放，则使用 StretchBlt
         BitBlt(
             *box_hdc_mem,
             0,
             0,
             width,
             height,
-            *box_hdc_monitor,
+            *box_hdc_desktop_window,
             x,
             y,
             SRCCOPY,
@@ -105,11 +101,12 @@ pub fn capture_monitor(
 }
 
 #[allow(unused)]
-pub fn capture_window(impl_window: &ImplWindow, width: i32, height: i32) -> XCapResult<RgbaImage> {
+pub fn capture_window(hwnd: HWND, width: i32, height: i32) -> XCapResult<RgbaImage> {
     unsafe {
-        let box_hdc_window: BoxHDC = BoxHDC::from(impl_window);
-        // 内存中的HDC
-        let box_hdc_mem = BoxHDC::new(CreateCompatibleDC(*box_hdc_window));
+        let box_hdc_window: BoxHDC = BoxHDC::from(hwnd);
+        // 内存中的HDC，使用 DeleteDC 函数释放
+        // https://learn.microsoft.com/zh-cn/windows/win32/api/wingdi/nf-wingdi-createcompatibledc
+        let box_hdc_mem = BoxHDC::new(CreateCompatibleDC(*box_hdc_window), None);
         let box_h_bitmap = BoxHBITMAP::new(CreateCompatibleBitmap(*box_hdc_window, width, height));
 
         // 使用SelectObject函数将这个位图选择到DC中
@@ -121,7 +118,7 @@ pub fn capture_window(impl_window: &ImplWindow, width: i32, height: i32) -> XCap
         // the window that are drawn using DirectComposition.
         // https://github.com/chromium/chromium/blob/main/ui/snapshot/snapshot_win.cc#L39-L45
         let flags = PW_CLIENTONLY.0 | PW_RENDERFULLCONTENT;
-        PrintWindow(impl_window.hwnd, *box_hdc_mem, PRINT_WINDOW_FLAGS(flags));
+        PrintWindow(hwnd, *box_hdc_mem, PRINT_WINDOW_FLAGS(flags));
 
         to_rgba_image(box_hdc_mem, box_h_bitmap, width, height)
     }

src/windows/impl_monitor.rs

@@ -5,27 +5,27 @@ use windows::{
     Win32::{
         Foundation::{BOOL, LPARAM, POINT, RECT, TRUE},
         Graphics::Gdi::{
-            EnumDisplayMonitors, GetDeviceCaps, GetMonitorInfoW,
-            MonitorFromPoint, DESKTOPHORZRES, DEVMODEW, DEVMODE_DISPLAY_ORIENTATION,
+            EnumDisplayMonitors, EnumDisplaySettingsW, GetDeviceCaps, GetMonitorInfoW,
+            MonitorFromPoint, DESKTOPHORZRES, DEVMODEW, DMDO_180, DMDO_270, DMDO_90, DMDO_DEFAULT,
             ENUM_CURRENT_SETTINGS, HDC, HMONITOR, HORZRES, MONITORINFO, MONITORINFOEXW,
             MONITOR_DEFAULTTONULL,
         },
         UI::WindowsAndMessaging::MONITORINFOF_PRIMARY,
     },
 };
-use windows::Win32::Graphics::Gdi::EnumDisplaySettingsW;
 
 use crate::error::{XCapError, XCapResult};
 
 use super::{boxed::BoxHDC, capture::capture_monitor, utils::wide_string_to_string};
 
-// A函数与W函数区别
+// A 函数与 W 函数区别
 // https://learn.microsoft.com/zh-cn/windows/win32/learnwin32/working-with-strings
 
 #[derive(Debug, Clone)]
 pub(crate) struct ImplMonitor {
     #[allow(unused)]
     pub hmonitor: HMONITOR,
+    #[allow(unused)]
     pub monitor_info_ex_w: MONITORINFOEXW,
     pub id: u32,
     pub name: String,
@@ -59,13 +59,7 @@ fn get_dev_mode_w(monitor_info_exw: &MONITORINFOEXW) -> XCapResult<DEVMODEW> {
     dev_mode_w.dmSize = mem::size_of::<DEVMODEW>() as u16;
 
     unsafe {
-        EnumDisplaySettingsW(
-            PCWSTR(sz_device),
-            ENUM_CURRENT_SETTINGS,
-            &mut dev_mode_w,
-            // EDS_RAWMODE,
-        )
-        .ok()?;
+        EnumDisplaySettingsW(PCWSTR(sz_device), ENUM_CURRENT_SETTINGS, &mut dev_mode_w).ok()?;
     };
 
     Ok(dev_mode_w)
@@ -80,23 +74,23 @@ impl ImplMonitor {
 
         // https://learn.microsoft.com/zh-cn/windows/win32/api/winuser/nf-winuser-getmonitorinfoa
         unsafe { GetMonitorInfoW(hmonitor, monitor_info_ex_w_ptr).ok()? };
-        let mut rc_monitor = monitor_info_ex_w.monitorInfo.rcMonitor;
 
         let dev_mode_w = get_dev_mode_w(&monitor_info_ex_w)?;
 
+        let dm_position = unsafe { dev_mode_w.Anonymous1.Anonymous2.dmPosition };
+        let dm_pels_width = dev_mode_w.dmPelsWidth;
+        let dm_pels_height = dev_mode_w.dmPelsHeight;
+
         let dm_display_orientation =
             unsafe { dev_mode_w.Anonymous1.Anonymous2.dmDisplayOrientation };
-
         let rotation = match dm_display_orientation {
-            DEVMODE_DISPLAY_ORIENTATION(0) => 0.0,
-            DEVMODE_DISPLAY_ORIENTATION(1) => 90.0,
-            DEVMODE_DISPLAY_ORIENTATION(2) => 180.0,
-            DEVMODE_DISPLAY_ORIENTATION(3) => 270.0,
-            _ => dm_display_orientation.0 as f32,
+            DMDO_90 => 90.0,
+            DMDO_180 => 180.0,
+            DMDO_270 => 270.0,
+            DMDO_DEFAULT => 0.0,
+            _ => 0.0,
         };
 
-        let dev_mode_w = get_dev_mode_w(&monitor_info_ex_w)?;
-
         let box_hdc_monitor = BoxHDC::from(&monitor_info_ex_w.szDevice);
 
         let scale_factor = unsafe {
@@ -106,23 +100,15 @@ impl ImplMonitor {
             physical_width as f32 / logical_width as f32
         };
 
-        unsafe {
-            rc_monitor.left = dev_mode_w.Anonymous1.Anonymous2.dmPosition.x;
-            rc_monitor.right = dev_mode_w.Anonymous1.Anonymous2.dmPosition.x + dev_mode_w.dmPelsWidth as i32;
-            rc_monitor.top  = dev_mode_w.Anonymous1.Anonymous2.dmPosition.y;
-            rc_monitor.bottom  = dev_mode_w.Anonymous1.Anonymous2.dmPosition.y + dev_mode_w.dmPelsHeight as i32;
-
-        }
-
         Ok(ImplMonitor {
             hmonitor,
             monitor_info_ex_w,
             id: hmonitor.0 as u32,
             name: wide_string_to_string(&monitor_info_ex_w.szDevice)?,
-            x: rc_monitor.left,
-            y: rc_monitor.top,
-            width: (rc_monitor.right - rc_monitor.left) as u32,
-            height: (rc_monitor.bottom - rc_monitor.top) as u32,
+            x: dm_position.x,
+            y: dm_position.y,
+            width: dm_pels_width,
+            height: dm_pels_height,
             rotation,
             scale_factor,
             frequency: dev_mode_w.dmDisplayFrequency as f32,
@@ -167,10 +153,6 @@ impl ImplMonitor {
 
 impl ImplMonitor {
     pub fn capture_image(&self) -> XCapResult<RgbaImage> {
-        // let width = ((self.width as f32) * self.scale_factor) as i32;
-        // let height = ((self.height as f32) * self.scale_factor) as i32;
-        // let x = ((self.x as f32) * self.scale_factor) as i32;
-        // let y = ((self.y as f32) * self.scale_factor) as i32;
-        capture_monitor(self,self.x,self.y, self.width as i32, self.height as i32)
+        capture_monitor(self.x, self.y, self.width as i32, self.height as i32)
     }
 }

src/windows/impl_window.rs

@@ -163,6 +163,6 @@ impl ImplWindow {
         let width = ((self.width as f32) * self.current_monitor.scale_factor) as i32;
         let height = ((self.height as f32) * self.current_monitor.scale_factor) as i32;
 
-        capture_window(self, width, height)
+        capture_window(self.hwnd, width, height)
     }
 }