// win32_window.cpp
bool Win32Window::CreateAndShow(const std::wstring& title,
                                const Point& origin,
                                const Size& size) {
 // ...此處省略代碼...
 // 這里創(chuàng)建了win32接口的句柄
  HWND window = CreateWindow(
      window_class, title.c_str(), WS_POPUP | WS_SYSMENU | WS_MINIMIZEBOX | WS_MAXIMIZEBOX,
      Scale(origin.x, scale_factor), Scale(origin.y, scale_factor),
      Scale(size.width, scale_factor), Scale(size.height, scale_factor),
      nullptr, nullptr, GetModuleHandle(nullptr), this);
  UpdateWindow(window);
  if (!window) {
    return false;
  }
  return OnCreate();
}

bool FlutterWindow::OnCreate() {
  if (!Win32Window::OnCreate()) {
    return false;
  }
  // GetClientArea獲取創(chuàng)建的win32Window區(qū)域
  RECT frame = GetClientArea();
  // 綁定窗口和flutter engine
  flutter_controller_ = std::make_unique<flutter::FlutterViewController>(
      frame.right - frame.left, frame.bottom - frame.top, project_);
  if (!flutter_controller_->engine() || !flutter_controller_->view()) {
    return false;
  }
  RegisterPlugins(flutter_controller_->engine());
  SetChildContent(flutter_controller_->view()->GetNativeWindow());
  return true;
}

<!-- android/app/src/main/res/values/styles.xml -->
<style name="Theme.DialogApp" parent="Theme.AppCompat.Light.Dialog"> 
    <item name="android:windowBackground">@drawable/launch_application</item> 
    <item name="android:windowIsTranslucent">true</item> 
    <item name="android:windowContentOverlay">@null</item> 
    <item name="android:backgroundDimEnabled">false</item> 
    <item name="windowActionBar">false</item> 
    <item name="windowNoTitle">true</item> 
</style>

<!-- android/app/src/main/AndroidManifest.xml -->
<activity
android:name=".MainActivity"
android:exported="true"
android:hardwareAccelerated="true"
android:launchMode="singleTop"
android:theme="@style/Theme.DialogApp"
android:windowSoftInputMode="adjustResize"> 
    <meta-data
        android:name="io.flutter.embedding.android.NormalTheme"
        android:resource="@style/Theme.DialogApp" /> 
    <intent-filter> 
        <action android:name="android.intent.action.MAIN" /> 
        <category android:name="android.intent.category.LAUNCHER" /> 
    </intent-filter>
</activity>

// android/app/src/main/kotlin/com/maxhub/upgrade_assistant/MainActivity.kt
class MainActivity : FlutterActivity() {
    override fun getTransparencyMode(): TransparencyMode {
        // 設(shè)置窗口背景透明
        return TransparencyMode.transparent
    }
    override fun onResume() {
        super.onResume()
        setFinishOnTouchOutside(false) // 點(diǎn)擊外部，dialog不消失
        // 設(shè)置窗口全屏
        var lp = window.attributes
        lp.width = -1
        lp.height = -1
        window.attributes = lp
    }
}

class GlobalBoxManager extends StatelessWidget {
  GlobalBoxManager({Key? key, required this.child}) : super(key: key);
  final Widget child;
  @override
  Widget build(BuildContext context) {
    return Container(
        width: ScreenUtil().screenWidth,
        height: ScreenUtil().screenHeight,
        // android偽全屏，加入邊距
        padding: EdgeInsets.symmetric(horizontal: 374.w, vertical: 173.h),
        child: child,
    );
  }
}

// MyApp下的build構(gòu)造方法
GlobalBoxManager(
  child: GetMaterialApp(
    locale: Get.deviceLocale,
    translations: Internationalization(),
    // 桌面應(yīng)用的頁(yè)面跳轉(zhuǎn)習(xí)慣是無(wú)動(dòng)畫的，符合用戶習(xí)慣
    defaultTransition: Transition.noTransition,
    transitionDuration: Duration.zero,
    theme: lightTheme,
    darkTheme: darkTheme,
    initialRoute: initialRoute,
    getPages: RouteConfig.getPages,
    title: 'appName'.tr,
  ),
),

dependencies:
  flutter:
    sdk: flutter
  window_manager: ^0.2.6

// runApp之前運(yùn)行
WindowManager w = WindowManager.instance;
await w.ensureInitialized();
WindowOptions windowOptions = WindowOptions(
  size: normalWindowSize,
  center: true,
  titleBarStyle: TitleBarStyle.hidden // 該屬性隱藏導(dǎo)航欄
);
w.waitUntilReadyToShow(windowOptions, () async {
  await w.setBackgroundColor(Colors.transparent);
  await w.show();
  await w.focus();
  await w.setAsFrameless();
});

// windows/runner/win32_window.cpp
HWND window = CreateWindow(
    // 去除WS_VISIBLE屬性
    window_class, title.c_str(), WS_OVERLAPPEDWINDOW,
    Scale(origin.x, scale_factor), Scale(origin.y, scale_factor),
    Scale(size.width, scale_factor), Scale(size.height, scale_factor),
    nullptr, nullptr, GetModuleHandle(nullptr), this);

import 'dart:io';
import 'package:flutter/material.dart';
class GlobalBoxManager extends StatelessWidget {
  const GlobalBoxManager({Key? key, required this.child}) : super(key: key);
  final Widget child;
  @override
  Widget build(BuildContext context) {
    return Container(
      width: double.infinity,
      height: double.infinity,
      // android偽全屏，加入邊距
      padding: Platform.isAndroid
          ? const EdgeInsets.symmetric(horizontal: 374, vertical: 173)
          : EdgeInsets.zero,
      child: Container(
        clipBehavior: Clip.antiAliasWithSaveLayer,
        margin: const EdgeInsets.all(10),
        decoration: const BoxDecoration(
            borderRadius: BorderRadius.all(Radius.circular(8)),
            boxShadow: [
              BoxShadow(color: Color(0x33000000), blurRadius: 8),
            ]),
        child: child,
      ),
    );
  }
}

@override
Widget build(BuildContext context) {
  return Scaffold(
    appBar: PreferredSize(
      preferredSize: const Size.fromHeight(64),
      child: GestureDetector(
        behavior: HitTestBehavior.translucent,
        onPanStart: (details) {
          if (Platform.isWindows) windowManager.startDragging();
        },
        onDoubleTap: () {},
        child: AppBar(
          title: Text(widget.title),
          centerTitle: true,
          actions: [
            GestureDetector(
              behavior: HitTestBehavior.opaque,
              child: const Padding(
                padding: EdgeInsets.symmetric(horizontal: 16),
                child: Icon(
                  Icons.close,
                  size: 24,
                ),
              ),
            ),
          ],
        ),
      ),
    ),
    body: Center(),
  );
}

import 'dart:ffi';
import 'package:ffi/ffi.dart';
import 'package:win32/win32.dart';
const maxItemLength= 2048;
class RegistryKeyValuePair {
  final String key;
  final String value;
  const RegistryKeyValuePair(this.key, this.value);
}
class RegistryUtil {
  /// 根據(jù)鍵名獲取注冊(cè)表的值
  static String? getRegeditForKey(String regPath, String key,
      {int hKeyValue = HKEY_LOCAL_MACHINE}) {
    var res = getRegedit(regPath, hKeyValue: hKeyValue);
    return res[key];
  }
  /// 設(shè)置注冊(cè)表值
  static setRegeditValue(String regPath, String key, String value,
      {int hKeyValue = HKEY_CURRENT_USER}) {
    final phKey = calloc<HANDLE>();
    final lpKeyPath = regPath.toNativeUtf16();
    final lpKey = key.toNativeUtf16();
    final lpValue = value.toNativeUtf16();
    try {
      if (RegSetKeyValue(hKeyValue, lpKeyPath, lpKey, REG_SZ, lpValue,
              lpValue.length * 2) !=
          ERROR_SUCCESS) {
        throw Exception("Can't set registry key");
      }
      return phKey.value;
    } finally {
      free(phKey);
      free(lpKeyPath);
      free(lpKey);
      free(lpValue);
      RegCloseKey(HKEY_CURRENT_USER);
    }
  }
  /// 獲取注冊(cè)表所有子項(xiàng)
  static List<String>? getRegeditKeys(String regPath,
      {int hKeyValue = HKEY_LOCAL_MACHINE}) {
    final hKey = _getRegistryKeyHandle(hKeyValue, regPath);
    var dwIndex = 0;
    String? key;
    List<String>? keysList;
    key = _enumerateKeyList(hKey, dwIndex);
    while (key != null) {
      keysList ??= [];
      keysList.add(key);
      dwIndex++;
      key = _enumerateKeyList(hKey, dwIndex);
    }
    RegCloseKey(hKey);
    return keysList;
  }
  /// 刪除注冊(cè)表的子項(xiàng)
  static bool deleteRegistryKey(String regPath, String subPath,
      {int hKeyValue = HKEY_LOCAL_MACHINE}) {
    final subKeyForPath = subPath.toNativeUtf16();
    final hKey = _getRegistryKeyHandle(hKeyValue, regPath);
    try {
      final status = RegDeleteKey(hKey, subKeyForPath);
      switch (status) {
        case ERROR_SUCCESS:
          return true;
        case ERROR_MORE_DATA:
          throw Exception('An item required more than $maxItemLength bytes.');
        case ERROR_NO_MORE_ITEMS:
          return false;
        default:
          throw Exception('unknown error');
      }
    } finally {
      RegCloseKey(hKey);
      free(subKeyForPath);
    }
  }
  /// 根據(jù)項(xiàng)的路徑獲取所有值
  static Map<String, String> getRegedit(String regPath,
      {int hKeyValue = HKEY_CURRENT_USER}) {
    final hKey = _getRegistryKeyHandle(hKeyValue, regPath);
    final Map<String, String> portsList = <String, String>{};
    /// The index of the value to be retrieved.
    var dwIndex = 0;
    RegistryKeyValuePair? item;
    item = _enumerateKey(hKey, dwIndex);
    while (item != null) {
      portsList[item.key] = item.value;
      dwIndex++;
      item = _enumerateKey(hKey, dwIndex);
    }
    RegCloseKey(hKey);
    return portsList;
  }
  static int _getRegistryKeyHandle(int hive, String key) {
    final phKey = calloc<HANDLE>();
    final lpKeyPath = key.toNativeUtf16();
    try {
      final res = RegOpenKeyEx(hive, lpKeyPath, 0, KEY_READ, phKey);
      if (res != ERROR_SUCCESS) {
        throw Exception("Can't open registry key");
      }
      return phKey.value;
    } finally {
      free(phKey);
      free(lpKeyPath);
    }
  }
  static RegistryKeyValuePair? _enumerateKey(int hKey, int index) {
    final lpValueName = wsalloc(MAX_PATH);
    final lpcchValueName = calloc<DWORD>()..value = MAX_PATH;
    final lpType = calloc<DWORD>();
    final lpData = calloc<BYTE>(maxItemLength);
    final lpcbData = calloc<DWORD>()..value = maxItemLength;
    try {
      final status = RegEnumValue(hKey, index, lpValueName, lpcchValueName,
          nullptr, lpType, lpData, lpcbData);
      switch (status) {
        case ERROR_SUCCESS:
          {
            // if (lpType.value != REG_SZ) throw Exception('Non-string content.');
            if (lpType.value == REG_DWORD) {
              return RegistryKeyValuePair(lpValueName.toDartString(),
                  lpData.cast<Uint32>().value.toString());
            }
            if (lpType.value == REG_SZ) {
              return RegistryKeyValuePair(lpValueName.toDartString(),
                  lpData.cast<Utf16>().toDartString());
            }
            break;
          }
        case ERROR_MORE_DATA:
          throw Exception('An item required more than $maxItemLength bytes.');
        case ERROR_NO_MORE_ITEMS:
          return null;
        default:
          throw Exception('unknown error');
      }
    } finally {
      free(lpValueName);
      free(lpcchValueName);
      free(lpType);
      free(lpData);
      free(lpcbData);
    }
    return null;
  }
  static String? _enumerateKeyList(int hKey, int index) {
    final lpValueName = wsalloc(MAX_PATH);
    final lpcchValueName = calloc<DWORD>()..value = MAX_PATH;
    try {
      final status = RegEnumKeyEx(hKey, index, lpValueName, lpcchValueName,
          nullptr, nullptr, nullptr, nullptr);
      switch (status) {
        case ERROR_SUCCESS:
          return lpValueName.toDartString();
        case ERROR_MORE_DATA:
          throw Exception('An item required more than $maxItemLength bytes.');
        case ERROR_NO_MORE_ITEMS:
          return null;
        default:
          throw Exception('unknown error');
      }
    } finally {
      free(lpValueName);
      free(lpcchValueName);
    }
  }
}

Process.start('ncpa.cpl', [],runInShell: true);

/// windows設(shè)置單實(shí)例啟動(dòng)
static setSingleInstance(List<String> args) async {
  await WindowsSingleInstance.ensureSingleInstance(args, "desktop_open",
      onSecondWindow: (args) async {
    // 喚起并聚焦
    if (await windowManager.isMinimized()) await windowManager.restore();
    windowManager.focus();
  });
}

TextButton(
  clipBehavior: Clip.antiAliasWithSaveLayer,
  style: ButtonStyle(
    animationDuration: Duration.zero, // 動(dòng)畫延時(shí)設(shè)置為0
    visualDensity: VisualDensity.compact,
    overlayColor: MaterialStateProperty.all(Colors.transparent),
    padding: MaterialStateProperty.all(EdgeInsets.zero),
    textStyle:
        MaterialStateProperty.all(Theme.of(context).textTheme.subtitle1),
    // 按鈕按下的時(shí)候的前景色，會(huì)讓文本的顏色按下時(shí)變?yōu)榘咨?
    foregroundColor: MaterialStateProperty.resolveWith((states) {
      return states.contains(MaterialState.pressed)
          ? Colors.white
          : Theme.of(context).toggleableActiveColor;
    }),
    // 按鈕按下的時(shí)候的背景色，會(huì)讓背景按下時(shí)變?yōu)樗{(lán)色
    backgroundColor: MaterialStateProperty.resolveWith((states) {
      return states.contains(MaterialState.pressed)
          ? Theme.of(context).toggleableActiveColor
          : null;
    }),
  ),
  onPressed: null,
  child: XXX),
)

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        val intent = intent
        handleSendText(intent) // Handle text being sent
    }
    override fun onRestart() {
        super.onRestart()
        flutterEngine!!.lifecycleChannel.appIsResumed()
    }
    override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
        super.configureFlutterEngine(flutterEngine)
        MethodChannel(flutterEngine.dartExecutor.binaryMessenger, channel)
            .setMethodCallHandler { call: MethodCall, result: MethodChannel.Result ->
                when (call.method) {
                    "getSharedText" -> {
                        result.success(sharedText)
                    }
                }
            }
    }
    private fun handleSendText(intent: Intent) {
        sharedText = intent.getStringExtra("params")
    }
}
```
Flutter層在main函數(shù)中通過(guò)Method Channel的方式取到MainActivity中存儲(chǔ)的參數(shù)，繞多了一層鏈路。
```dart
const platform = MethodChannel('app.open.shared.data');
String? sharedData = await platform.invokeMethod('getSharedText');
if (sharedData == null) return null;
return jsonDecode(sharedData);
```