窗口事件

Wails 通过统一的 API 分发窗口生命周期和状态变更事件：OnWindowEvent用于被动监听器，RegisterHook用于可取消默认操作的钩子。

import "github.com/wailsapp/wails/v3/pkg/events"

// Listener — observes the event, cannot cancel it.
window.OnWindowEvent(events.Common.WindowDidResize, func(e *application.WindowEvent) { /* ... */ })

// Hook — runs before listeners; can call e.Cancel() to suppress the default action.
window.RegisterHook(events.Common.WindowClosing, func(e *application.WindowEvent) {
    if hasUnsavedChanges() {
        e.Cancel() // prevent the window from closing
    }
})

这两种调用都会返回一个unsubscribe func()，你可以调用它来移除处理程序。

跨平台事件位于events.Common.*中。平台特定事件位于events.Mac.*、events.Windows.*和events.Linux.*中。完整列表生成在v3/pkg/events/events.go中。

生命周期事件

窗口创建

使用app.Window.OnCreate在每次创建窗口时运行回调：

app.Window.OnCreate(func(window application.Window) {
    fmt.Printf("Window created: %s (ID: %d)\n", window.Name(), window.ID())

    // Configure all new windows
    window.SetMinSize(400, 300)

    // Register a hook for this window
    window.RegisterHook(events.Common.WindowClosing, func(e *application.WindowEvent) {
        if !confirmClose() {
            e.Cancel()
        }
    })
})

该回调接收application.Window（一个接口）。每个窗口的OnCreate回调都会在窗口运行时初始化完成后调用一次。

WindowClosing

当用户尝试关闭窗口时触发（单击 X、按 ⌘W、Alt+F4 等）。

使用钩子（RegisterHook）——只有钩子才能取消关闭操作。监听器只能观察事件，无法阻止关闭。

window.RegisterHook(events.Common.WindowClosing, func(e *application.WindowEvent) {
    if hasUnsavedChanges() {
        // Cancel the close — the window stays open.
        e.Cancel()
    }
})

重要：

WindowClosing在用户发起关闭尝试时分发。
RegisterHook回调可以调用e.Cancel()以保持窗口打开。
WindowClosing的OnWindowEvent回调是观察者——它们会触发，但无法取消操作。

以编程方式关闭：调用window.Close()。不存在window.Destroy()。

WindowRuntimeReady

窗口内运行时完成初始化后触发——此时可以安全地调用窗口的 JS 上下文：

window.OnWindowEvent(events.Common.WindowRuntimeReady, func(e *application.WindowEvent) {
    window.EmitEvent("app-ready", nil)
})

焦点事件

WindowFocus

窗口获得焦点时调用：

window.OnWindowEvent(events.Common.WindowFocus, func(e *application.WindowEvent) {
    fmt.Println("Window gained focus")
    updateTitleBar(true)
    app.Event.Emit("window-focused", window.ID())
})

WindowLostFocus

窗口失去焦点时调用：

window.OnWindowEvent(events.Common.WindowLostFocus, func(e *application.WindowEvent) {
    fmt.Println("Window lost focus")
    updateTitleBar(false)
    saveCurrentState()
})

示例：感知焦点的 UI：

type FocusAwareWindow struct {
    window  *application.WebviewWindow
    focused bool
}

func (fw *FocusAwareWindow) Setup() {
    fw.window.OnWindowEvent(events.Common.WindowFocus, func(e *application.WindowEvent) {
        fw.focused = true
        fw.updateAppearance()
    })

    fw.window.OnWindowEvent(events.Common.WindowLostFocus, func(e *application.WindowEvent) {
        fw.focused = false
        fw.updateAppearance()
    })
}

func (fw *FocusAwareWindow) updateAppearance() {
    if fw.focused {
        fw.window.EmitEvent("update-theme", "active")
    } else {
        fw.window.EmitEvent("update-theme", "inactive")
    }
}

状态变更事件

WindowMinimise / WindowUnMinimise

window.OnWindowEvent(events.Common.WindowMinimise, func(e *application.WindowEvent) {
    pauseRendering()
    saveWindowState()
})

window.OnWindowEvent(events.Common.WindowUnMinimise, func(e *application.WindowEvent) {
    resumeRendering()
    refreshContent()
})

WindowMaximise / WindowUnMaximise

window.OnWindowEvent(events.Common.WindowMaximise, func(e *application.WindowEvent) {
    window.EmitEvent("layout-mode", "maximised")
})

window.OnWindowEvent(events.Common.WindowUnMaximise, func(e *application.WindowEvent) {
    window.EmitEvent("layout-mode", "normal")
})

WindowFullscreen / WindowUnFullscreen

window.OnWindowEvent(events.Common.WindowFullscreen, func(e *application.WindowEvent) {
    window.EmitEvent("chrome-visibility", false)
    window.EmitEvent("layout-mode", "fullscreen")
})

window.OnWindowEvent(events.Common.WindowUnFullscreen, func(e *application.WindowEvent) {
    window.EmitEvent("chrome-visibility", true)
    window.EmitEvent("layout-mode", "normal")
})

使用window.Fullscreen() / window.UnFullscreen() / window.ToggleFullscreen()以编程方式进入或退出全屏——不存在SetFullscreen(bool)。使用window.IsFullscreen() bool查询状态。

位置和大小事件

WindowDidMove

window.OnWindowEvent(events.Common.WindowDidMove, func(e *application.WindowEvent) {
    x, y := window.Position()
    fmt.Printf("Window moved to: %d, %d\n", x, y)
    saveWindowPosition(x, y)
})

WindowDidResize

window.OnWindowEvent(events.Common.WindowDidResize, func(e *application.WindowEvent) {
    width, height := window.Size()
    fmt.Printf("Window resized to: %dx%d\n", width, height)
    saveWindowSize(width, height)
    window.EmitEvent("window-size", map[string]int{
        "width":  width,
        "height": height,
    })
})

WindowDidResize和WindowDidMove事件本身不携带坐标——请在回调中通过window.Size() / window.Position()查询窗口。

示例：响应式布局：

window.OnWindowEvent(events.Common.WindowDidResize, func(e *application.WindowEvent) {
    width, _ := window.Size()
    var layout string
    switch {
    case width < 600:
        layout = "compact"
    case width < 1200:
        layout = "normal"
    default:
        layout = "wide"
    }
    window.EmitEvent("layout-changed", layout)
})

完整示例

一个具有完整事件处理功能、可用于生产环境的窗口：

package main

import (
    "encoding/json"
    "fmt"
    "os"

    "github.com/wailsapp/wails/v3/pkg/application"
    "github.com/wailsapp/wails/v3/pkg/events"
)

type WindowState struct {
    X          int  `json:"x"`
    Y          int  `json:"y"`
    Width      int  `json:"width"`
    Height     int  `json:"height"`
    Maximised  bool `json:"maximised"`
    Fullscreen bool `json:"fullscreen"`
}

type ManagedWindow struct {
    app    *application.App
    window *application.WebviewWindow
    state  WindowState
    dirty  bool
}

func main() {
    app := application.New(application.Options{
        Name: "Event Demo",
    })

    mw := &ManagedWindow{app: app}
    mw.CreateWindow()
    mw.LoadState()
    mw.SetupEventHandlers()

    app.Run()
}

func (mw *ManagedWindow) CreateWindow() {
    mw.window = mw.app.Window.NewWithOptions(application.WebviewWindowOptions{
        Name:   "main",
        Title:  "Event Demo",
        Width:  800,
        Height: 600,
    })
}

func (mw *ManagedWindow) SetupEventHandlers() {
    // Focus events
    mw.window.OnWindowEvent(events.Common.WindowFocus, func(e *application.WindowEvent) {
        mw.window.EmitEvent("focus-state", true)
    })

    mw.window.OnWindowEvent(events.Common.WindowLostFocus, func(e *application.WindowEvent) {
        mw.window.EmitEvent("focus-state", false)
    })

    // State change events
    mw.window.OnWindowEvent(events.Common.WindowMinimise, func(e *application.WindowEvent) {
        mw.SaveState()
    })

    mw.window.OnWindowEvent(events.Common.WindowMaximise, func(e *application.WindowEvent) {
        mw.state.Maximised = true
        mw.dirty = true
    })

    mw.window.OnWindowEvent(events.Common.WindowUnMaximise, func(e *application.WindowEvent) {
        mw.state.Maximised = false
        mw.dirty = true
    })

    mw.window.OnWindowEvent(events.Common.WindowFullscreen, func(e *application.WindowEvent) {
        mw.state.Fullscreen = true
        mw.dirty = true
    })

    mw.window.OnWindowEvent(events.Common.WindowUnFullscreen, func(e *application.WindowEvent) {
        mw.state.Fullscreen = false
        mw.dirty = true
    })

    // Position and size events
    mw.window.OnWindowEvent(events.Common.WindowDidMove, func(e *application.WindowEvent) {
        mw.state.X, mw.state.Y = mw.window.Position()
        mw.dirty = true
    })

    mw.window.OnWindowEvent(events.Common.WindowDidResize, func(e *application.WindowEvent) {
        mw.state.Width, mw.state.Height = mw.window.Size()
        mw.dirty = true
    })

    // Cancellable close — use a hook, not a listener.
    mw.window.RegisterHook(events.Common.WindowClosing, func(e *application.WindowEvent) {
        if mw.dirty {
            mw.SaveState()
        }
    })
}

func (mw *ManagedWindow) LoadState() {
    data, err := os.ReadFile("window-state.json")
    if err != nil {
        return
    }

    if err := json.Unmarshal(data, &mw.state); err != nil {
        return
    }

    // Restore window state
    mw.window.SetPosition(mw.state.X, mw.state.Y)
    mw.window.SetSize(mw.state.Width, mw.state.Height)

    if mw.state.Maximised {
        mw.window.Maximise()
    }

    if mw.state.Fullscreen {
        mw.window.Fullscreen()
    }
}

func (mw *ManagedWindow) SaveState() {
    data, err := json.Marshal(mw.state)
    if err != nil {
        return
    }

    os.WriteFile("window-state.json", data, 0644)
    mw.dirty = false

    fmt.Println("Window state saved")
}

事件协调

跨窗口事件

使用应用程序事件总线在多个窗口之间进行协调：

// In main window
mainWindow.OnWindowEvent(events.Common.WindowFocus, func(e *application.WindowEvent) {
    app.Event.Emit("main-window-focused", nil)
})

// In other windows
app.Event.On("main-window-focused", func(event *application.CustomEvent) {
    updateRelativeToMain()
})

事件链

window.OnWindowEvent(events.Common.WindowMaximise, func(e *application.WindowEvent) {
    saveWindowState()
    window.EmitEvent("layout-changed", "maximised")
    app.Event.Emit("window-maximised", window.ID())
})

防抖事件

var resizeTimer *time.Timer

window.OnWindowEvent(events.Common.WindowDidResize, func(e *application.WindowEvent) {
    if resizeTimer != nil {
        resizeTimer.Stop()
    }

    resizeTimer = time.AfterFunc(500*time.Millisecond, func() {
        w, h := window.Size()
        saveWindowSize(w, h)
    })
})

最佳实践

✅ 应该做

使用钩子取消操作——只有RegisterHook回调可以调用e.Cancel()。
关闭时保存状态——下次启动时恢复窗口的位置和大小。
对高频事件进行防抖——WindowDidResize和WindowDidMove会快速连续触发。
处理焦点变化——相应地更新 UI。
通过事件进行协调——使用app.Event.Emit进行跨窗口消息传递。
取消订阅不再需要的处理程序——OnWindowEvent和RegisterHook都会返回一个用于取消订阅的func()。

❌ 不应该做

不要阻塞事件处理程序——应让它们快速完成。
不要尝试从OnWindowEvent中取消操作——请使用RegisterHook。
不要使用window.Destroy()——它不存在；请使用window.Close()。
不要在每次事件触发时都保存——应先进行防抖。
不要假定事件中包含坐标——请调用window.Position() / window.Size()。

故障排除

WindowClosing 钩子无法阻止关闭

原因：你使用了OnWindowEvent，而不是RegisterHook。

解决方案：只有RegisterHook回调可以调用e.Cancel()。OnWindowEvent回调只能观察，无法取消操作。

// ❌ Cannot cancel — this is a listener.
window.OnWindowEvent(events.Common.WindowClosing, func(e *application.WindowEvent) {
    e.Cancel() // no effect
})

// ✅ Can cancel — this is a hook.
window.RegisterHook(events.Common.WindowClosing, func(e *application.WindowEvent) {
    e.Cancel()
})

事件未触发

原因：事件发生后才注册处理程序。

解决方案：创建窗口后立即注册处理程序（或在app.Window.OnCreate回调中注册）。

window := app.Window.New()
window.OnWindowEvent(events.Common.WindowFocus, func(e *application.WindowEvent) { /* ... */ })

内存泄漏

原因：短生命周期状态持有了长生命周期的处理程序。

解决方案：保存OnWindowEvent/RegisterHook返回的取消订阅func()，并在清理时调用它。

unsub := window.OnWindowEvent(events.Common.WindowDidResize, handler)
// ...later:
unsub()

后续步骤

窗口基础 - 了解窗口管理的基础知识了解更多 →

多窗口 - 了解多窗口应用的设计模式了解更多 →

事件系统 - 深入了解事件系统了解更多 →

应用生命周期 - 了解应用生命周期了解更多 →

有疑问？请在Discord中提问，或查看示例。

无障碍

编辑此文档

窗口事件

窗口事件

生命周期事件

窗口创建

WindowClosing

WindowRuntimeReady

焦点事件

WindowFocus

WindowLostFocus

状态变更事件

WindowMinimise / WindowUnMinimise

WindowMaximise / WindowUnMaximise

WindowFullscreen / WindowUnFullscreen

位置和大小事件

WindowDidMove

WindowDidResize

完整示例

事件协调

跨窗口事件

事件链

防抖事件

最佳实践

✅ 应该做

❌ 不应该做

故障排除

WindowClosing 钩子无法阻止关闭

事件未触发

内存泄漏

后续步骤