fix: 修复hdc释放错误问题

nashaofu · Jan 26, 2024 · 4c12ea0 · 4c12ea0
1 parent 52f06a8
commit 4c12ea0
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Showing 3 changed files with 27 additions and 13 deletions.
diff --git a/src/windows/boxed.rs b/src/windows/boxed.rs
@@ -3,30 +3,39 @@ use windows::{
     core::PCWSTR,
     Win32::{
         Foundation::HWND,
-        Graphics::Gdi::{CreateDCW, DeleteDC, DeleteObject, GetWindowDC, HBITMAP, HDC},
+        Graphics::Gdi::{CreateDCW, DeleteDC, DeleteObject, GetWindowDC, ReleaseDC, HBITMAP, HDC},
     },
 };
 
-pub(super) 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 }
     }
 }
 
@@ -43,15 +52,17 @@ impl From<&[u16; 32]> for BoxHDC {
             )
         };
 
-        BoxHDC::new(hdc)
+        BoxHDC::new(hdc, None)
     }
 }
 
 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))
     }
 }
 
@@ -66,6 +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);
         };

diff --git a/src/windows/capture.rs b/src/windows/capture.rs
@@ -69,8 +69,9 @@ pub fn capture_monitor(x: i32, y: i32, width: i32, height: i32) -> XCapResult<Rg
         let hwnd = GetDesktopWindow();
         let box_hdc_desktop_window = BoxHDC::from(hwnd);
 
-        // 内存中的HDC
-        let box_hdc_mem = BoxHDC::new(CreateCompatibleDC(*box_hdc_desktop_window));
+        // 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,
@@ -103,8 +104,9 @@ pub fn capture_monitor(x: i32, y: i32, width: i32, height: i32) -> XCapResult<Rg
 pub fn capture_window(hwnd: HWND, width: i32, height: i32) -> XCapResult<RgbaImage> {
     unsafe {
         let box_hdc_window: BoxHDC = BoxHDC::from(hwnd);
-        // 内存中的HDC
-        let box_hdc_mem = BoxHDC::new(CreateCompatibleDC(*box_hdc_window));
+        // 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

diff --git a/src/windows/impl_monitor.rs b/src/windows/impl_monitor.rs
@@ -18,7 +18,7 @@ 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)]