Add Windows string conversion utilities and update usage

Introduced string_utils_windows.h with functions for converting between std::string and std::wstring, and for handling WCHAR arrays. Updated display, menu, tray icon, window manager, and window implementations to use these utilities for proper UTF-8/UTF-16 conversions, improving Unicode support in Windows API calls.

Author: lijy91

src/platform/windows/display_windows.cpp

@@ -1,6 +1,7 @@
 #include "../../display.h"
 
 #include <windows.h>
+#include "string_utils_windows.h"
 
 namespace nativeapi {
 
@@ -65,7 +66,7 @@ std::string Display::GetName() const {
   if (!pimpl_->h_monitor_)
     return "";
   MONITORINFOEX monitorInfo = GetMonitorInfo(pimpl_->h_monitor_);
-  return monitorInfo.szDevice;
+  return WCharArrayToString(monitorInfo.szDevice);
 }
 
 Point Display::GetPosition() const {

src/platform/windows/menu_windows.cpp

@@ -5,6 +5,7 @@
 #include <vector>
 #include "../../menu.h"
 #include "../../menu_event.h"
+#include "string_utils_windows.h"
 
 namespace nativeapi {
 
@@ -151,8 +152,9 @@ void MenuItem::SetLabel(const std::optional<std::string>& label) {
     MENUITEMINFO mii = {};
     mii.cbSize = sizeof(MENUITEMINFO);
     mii.fMask = MIIM_STRING;
-    const char* labelStr = label.has_value() ? label->c_str() : "";
-    mii.dwTypeData = const_cast<LPSTR>(labelStr);
+    std::string labelStr = label.has_value() ? *label : "";
+    std::wstring wLabelStr = StringToWString(labelStr);
+    mii.dwTypeData = const_cast<LPWSTR>(wLabelStr.c_str());
     SetMenuItemInfo(pimpl_->parent_menu_, pimpl_->menu_item_id_, FALSE, &mii);
   }
 }
@@ -355,8 +357,9 @@ void Menu::AddItem(std::shared_ptr<MenuItem> item) {
   }
 
   auto labelOpt = item->GetLabel();
-  const char* labelStr = labelOpt.has_value() ? labelOpt->c_str() : "";
-  AppendMenu(pimpl_->hmenu_, flags, menuId, labelStr);
+  std::string labelStr = labelOpt.has_value() ? *labelOpt : "";
+  std::wstring wLabelStr = StringToWString(labelStr);
+  AppendMenu(pimpl_->hmenu_, flags, menuId, wLabelStr.c_str());
 
   // Update the item's impl with menu info
   item->pimpl_->parent_menu_ = pimpl_->hmenu_;
@@ -380,9 +383,10 @@ void Menu::InsertItem(size_t index, std::shared_ptr<MenuItem> item) {
   }
 
   auto labelOpt = item->GetLabel();
-  const char* labelStr = labelOpt.has_value() ? labelOpt->c_str() : "";
+  std::string labelStr = labelOpt.has_value() ? *labelOpt : "";
+  std::wstring wLabelStr = StringToWString(labelStr);
   InsertMenu(pimpl_->hmenu_, static_cast<UINT>(index), flags, item->id,
-             labelStr);
+             wLabelStr.c_str());
 
   item->pimpl_->parent_menu_ = pimpl_->hmenu_;
   item->pimpl_->menu_item_id_ = static_cast<UINT>(item->id);

src/platform/windows/string_utils_windows.h

@@ -0,0 +1,40 @@
+#ifndef NATIVEAPI_PLATFORM_WINDOWS_STRING_UTILS_H_
+#define NATIVEAPI_PLATFORM_WINDOWS_STRING_UTILS_H_
+
+#include <windows.h>
+#include <string>
+
+namespace nativeapi {
+namespace {  // 匿名命名空间，仅在包含此头文件的编译单元内可见
+
+// Convert std::string (UTF-8) to std::wstring (UTF-16)
+inline std::wstring StringToWString(const std::string& str) {
+  if (str.empty()) return std::wstring();
+  
+  int size_needed = MultiByteToWideChar(CP_UTF8, 0, str.c_str(), (int)str.size(), nullptr, 0);
+  std::wstring wstr(size_needed, 0);
+  MultiByteToWideChar(CP_UTF8, 0, str.c_str(), (int)str.size(), &wstr[0], size_needed);
+  return wstr;
+}
+
+// Convert std::wstring (UTF-16) to std::string (UTF-8)
+inline std::string WStringToString(const std::wstring& wstr) {
+  if (wstr.empty()) return std::string();
+  
+  int size_needed = WideCharToMultiByte(CP_UTF8, 0, wstr.c_str(), (int)wstr.size(), nullptr, 0, nullptr, nullptr);
+  std::string str(size_needed, 0);
+  WideCharToMultiByte(CP_UTF8, 0, wstr.c_str(), (int)wstr.size(), &str[0], size_needed, nullptr, nullptr);
+  return str;
+}
+
+// Convert WCHAR array to std::string
+inline std::string WCharArrayToString(const WCHAR* wchar_array) {
+  if (!wchar_array) return std::string();
+  return WStringToString(std::wstring(wchar_array));
+}
+
+}  // anonymous namespace
+}  // namespace nativeapi
+
+#endif  // NATIVEAPI_PLATFORM_WINDOWS_STRING_UTILS_H_
+

src/platform/windows/tray_icon_windows.cpp

@@ -7,6 +7,7 @@
 #include "../../menu.h"
 #include "../../tray_icon.h"
 #include "../../tray_icon_event.h"
+#include "string_utils_windows.h"
 
 namespace nativeapi {
 
@@ -102,16 +103,18 @@ TrayIcon::TrayIcon() : id(-1), pimpl_(std::make_unique<Impl>()) {
   static UINT next_class_id = 1;
   std::string class_name =
       "NativeAPITrayIcon_" + std::to_string(next_class_id++);
+  std::wstring wclass_name = StringToWString(class_name);
 
   WNDCLASS wc = {};
   wc.lpfnWndProc = DefWindowProc;
   wc.hInstance = hInstance;
-  wc.lpszClassName = class_name.c_str();
+  wc.lpszClassName = wclass_name.c_str();
 
   if (RegisterClass(&wc)) {
     // Create hidden message-only window
+    std::wstring wtitle = StringToWString("NativeAPI Tray Icon");
     HWND hwnd =
-        CreateWindow(class_name.c_str(), "NativeAPI Tray Icon", 0, 0, 0, 0, 0,
+        CreateWindow(wclass_name.c_str(), wtitle.c_str(), 0, 0, 0, 0, 0,
                      HWND_MESSAGE,  // Message-only window
                      nullptr, hInstance, nullptr);
 
@@ -148,12 +151,13 @@ void TrayIcon::SetIcon(std::string icon) {
     hIcon = LoadIcon(nullptr, IDI_APPLICATION);
   } else if (!icon.empty()) {
     // Try to load as file path first
-    hIcon = (HICON)LoadImage(nullptr, icon.c_str(), IMAGE_ICON, 16, 16,
+    std::wstring wicon = StringToWString(icon);
+    hIcon = (HICON)LoadImage(nullptr, wicon.c_str(), IMAGE_ICON, 16, 16,
                              LR_LOADFROMFILE);
 
     // If file path failed, try as resource
     if (!hIcon) {
-      hIcon = LoadIcon(GetModuleHandle(nullptr), icon.c_str());
+      hIcon = LoadIcon(GetModuleHandle(nullptr), wicon.c_str());
     }
 
     // If still failed, use default application icon
@@ -193,10 +197,10 @@ std::optional<std::string> TrayIcon::GetTitle() {
 
 void TrayIcon::SetTooltip(std::optional<std::string> tooltip) {
   if (pimpl_->hwnd_) {
-    const char* tooltip_str = tooltip.has_value() ? tooltip->c_str() : "";
-    strncpy_s(pimpl_->nid_.szTip, tooltip_str,
-              sizeof(pimpl_->nid_.szTip) - 1);
-    pimpl_->nid_.szTip[sizeof(pimpl_->nid_.szTip) - 1] = '\0';
+    std::string tooltip_str = tooltip.has_value() ? *tooltip : "";
+    std::wstring wtooltip = StringToWString(tooltip_str);
+    wcsncpy_s(pimpl_->nid_.szTip, sizeof(pimpl_->nid_.szTip) / sizeof(WCHAR), 
+              wtooltip.c_str(), _TRUNCATE);
 
     // Update if icon is visible (check if hIcon is set as indicator)
     if (pimpl_->nid_.hIcon) {
@@ -206,8 +210,8 @@ void TrayIcon::SetTooltip(std::optional<std::string> tooltip) {
 }
 
 std::optional<std::string> TrayIcon::GetTooltip() {
-  if (pimpl_->hwnd_ && pimpl_->nid_.szTip[0] != '\0') {
-    return std::string(pimpl_->nid_.szTip);
+  if (pimpl_->hwnd_ && pimpl_->nid_.szTip[0] != L'\0') {
+    return WCharArrayToString(pimpl_->nid_.szTip);
   }
   return std::nullopt;
 }

src/platform/windows/window_manager_windows.cpp

@@ -5,6 +5,7 @@
 #include "../../window.h"
 #include "../../window_event.h"
 #include "../../window_manager.h"
+#include "string_utils_windows.h"
 
 namespace nativeapi {
 
@@ -114,13 +115,13 @@ std::shared_ptr<Window> WindowManager::Create(const WindowOptions& options) {
 
   // Register window class if not already registered
   static bool class_registered = false;
-  const char* class_name = "NativeAPIWindow";
+  static std::wstring wclass_name = StringToWString("NativeAPIWindow");
 
   if (!class_registered) {
     WNDCLASS wc = {};
     wc.lpfnWndProc = WindowProc;
     wc.hInstance = hInstance;
-    wc.lpszClassName = class_name;
+    wc.lpszClassName = wclass_name.c_str();
     wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
     wc.hCursor = LoadCursor(nullptr, IDC_ARROW);
 
@@ -140,8 +141,9 @@ std::shared_ptr<Window> WindowManager::Create(const WindowOptions& options) {
   // Create the window
   DWORD style = WS_OVERLAPPEDWINDOW;
   DWORD exStyle = 0;
+  std::wstring wtitle = StringToWString(options.title);
 
-  HWND hwnd = CreateWindowEx(exStyle, class_name, options.title.c_str(), style,
+  HWND hwnd = CreateWindowEx(exStyle, wclass_name.c_str(), wtitle.c_str(), style,
                              CW_USEDEFAULT, CW_USEDEFAULT,
                              static_cast<int>(options.size.width),
                              static_cast<int>(options.size.height), nullptr,

src/platform/windows/window_windows.cpp

@@ -2,6 +2,7 @@
 #include <iostream>
 #include "../../window.h"
 #include "../../window_manager.h"
+#include "string_utils_windows.h"
 
 namespace nativeapi {
 
@@ -393,7 +394,8 @@ Point Window::GetPosition() const {
 
 void Window::SetTitle(std::string title) {
   if (pimpl_->hwnd_) {
-    SetWindowText(pimpl_->hwnd_, title.c_str());
+    std::wstring wtitle = StringToWString(title);
+    SetWindowText(pimpl_->hwnd_, wtitle.c_str());
   }
 }
 
@@ -405,9 +407,10 @@ std::string Window::GetTitle() const {
   if (length == 0)
     return "";
 
-  std::string title(length, '\0');
-  GetWindowText(pimpl_->hwnd_, &title[0], length + 1);
-  return title;
+  std::wstring wtitle(length + 1, L'\0');
+  GetWindowText(pimpl_->hwnd_, &wtitle[0], length + 1);
+  wtitle.resize(length);
+  return WStringToString(wtitle);
 }
 
 void Window::SetHasShadow(bool has_shadow) {