当前位置：首页 > news >正文

golang调用webview，webview2，go-webview2

news 2025/2/23 13:49:50

go version go1.20 windows/amd64

先要了解一些第三方库

1、webview/webview

它是一个跨平台的轻量级的webview库，面向的是C/C++，使用它可以构建跨平台的GUI。webview就是浏览器内核，在不同操作系统上是不同的库，比如在windows上为webview2，所以webview与webview2不要搞混了。从功能上，它实现了Javascript与C/C++之间的相互调用，即bindings。具体实现原理应该与wails差不多。

在不同平台上的支持如下

Platform	Technologies
Linux	GTK, WebKitGTK
macOS	Cocoa, WebKit
Windows	Windows API, WebView2

windows api 是windows系统提供的DLL（user32.dll），以此来构建windows上原生的GUI程序。

webview2是微软的Edge浏览器内核，用它来渲染前端页面，下载地址，所以这是两种不同的实现方式。而且webview2只支持windows系统。如果你的系统是Windows 10+，那么 WebView2 Runtime会默认安装了。

2、webview/webview_go

它使用Golang将webview/webview包装了一下，但是使用的是CGO，即webview/webview_go依赖于webview/webview，并使用CGO将依赖引入。

项目还不完善，我的本地系统x86_64-w64-mingw32下面找不到EventToken.h头文件，所以代码无法运行，Support for EventToken.h on mingw64 #45 依然没有解决。

3、jchv/go-webview2

它借鉴了webview/webview，使用Golang包装了webview2，不需要使用CGO，这是与webview_go的不同，当然此包只支持windows，因为它只是包装了webview2。在wails中使用的就是 jchv/go-webview2

它提供了一个示例：cmd/demo/main.go

import ("log""github.com/jchv/go-webview2"
)func main() {w := webview2.NewWithOptions(webview2.WebViewOptions{Debug:     true,AutoFocus: true,WindowOptions: webview2.WindowOptions{Title:  "Minimal webview example",Width:  800,Height: 600,IconId: 2, // icon resource idCenter: true,},})if w == nil {log.Fatalln("Failed to load webview.")}defer w.Destroy()w.SetSize(800, 600, webview2.HintFixed)w.Navigate("https://en.m.wikipedia.org/wiki/Main_Page")w.Run()
}

在这里插入图片描述

go-webview2简要说明

webviewloader\module.go

先使用windows.NewLazyDLL("WebView2Loader")加载WebView2Loader.dll，如果没有找到，它会使用go-winloader库来加载go-webview2自带的WebView2Loader.dll文件（webviewloader/sdk/x64下）。

webview2的参考文档：https://learn.microsoft.com/zh-cn/microsoft-edge/webview2/

go-webview2基本已经封装的很好了，下面是一个WebView对象提供的功能。

// WebView is the interface for the webview.
type WebView interface {// Run runs the main loop until it's terminated. After this function exits -// you must destroy the webview.Run()// Terminate stops the main loop. It is safe to call this function from// a background thread.Terminate()// Dispatch posts a function to be executed on the main thread. You normally// do not need to call this function, unless you want to tweak the native// window.Dispatch(f func())// Destroy destroys a webview and closes the native window.Destroy()// Window returns a native window handle pointer. When using GTK backend the// pointer is GtkWindow pointer, when using Cocoa backend the pointer is// NSWindow pointer, when using Win32 backend the pointer is HWND pointer.Window() unsafe.Pointer// SetTitle updates the title of the native window. Must be called from the UI// thread.SetTitle(title string)// SetSize updates native window size. See Hint constants.SetSize(w int, h int, hint Hint)// Navigate navigates webview to the given URL. URL may be a data URI, i.e.// "data:text/text,<html>...</html>". It is often ok not to url-encode it// properly, webview will re-encode it for you.Navigate(url string)// SetHtml sets the webview HTML directly.// The origin of the page is `about:blank`.SetHtml(html string)// Init injects JavaScript code at the initialization of the new page. Every// time the webview will open a the new page - this initialization code will// be executed. It is guaranteed that code is executed before window.onload.Init(js string)// Eval evaluates arbitrary JavaScript code. Evaluation happens asynchronously,// also the result of the expression is ignored. Use RPC bindings if you want// to receive notifications about the results of the evaluation.Eval(js string)// Bind binds a callback function so that it will appear under the given name// as a global JavaScript function. Internally it uses webview_init().// Callback receives a request string and a user-provided argument pointer.// Request string is a JSON array of all the arguments passed to the// JavaScript function.//// f must be a function// f must return either value and error or just errorBind(name string, f interface{}) error
}

Navigate方法的参数

网络地址：https://en.m.wikipedia.org/wiki/Main_Page
文件系统地址：file:///D:/dev/php/magook/trunk/server/go-webview/test.html，要使用绝对地址。当然，只要是浏览器能识别的文件都行，比如图片，网页，TXT文件等等。
直接展示内容：就是将文件的内容复制进去，此时就需要指定内容是什么形式的，如果不指定就无法展示出来。格式为mimetype,content，其中 mimetype的常用的有data:image/gif, data:image/webp, data:image/jpeg, data:image/png, data:text/html, data:text/text，它会严格按照mimetype渲染，所以类型一定要对。
但是不推荐这种用法，我发现它会将本行中#后面的内容当做注释舍弃掉，比如

......
let option_CrGrDQTOQuKK = {"color":["#5470c6","#91cc75","#fac858","#ee6666","#73c0de","#3ba272","#fc8452","#9a60b4","#ea7ccc"],"legend":{},"series":[{"name":"Category A","type":"bar","data":[{"value":235},{"value":41},{"value":90},{"value":256},{"value":202},{"value":40},{"value":11}]},{"name":"Category B","type":"bar","data":[{"value":277},{"value":69},{"value":158},{"value":274},{"value":116},{"value":43},{"value":233}]}],"title":{"text":"My first bar chart generated by go-echarts","subtext":"It's extremely easy to use, right?"},"toolbox":{},"tooltip":{},"xAxis":[{"data":["Mon","Tue","Wed","Thu","Fri","Sat","Sun"]}],"yAxis":[{}]}
......

你会发现这一行只剩下了let option_CrGrDQTOQuKK = {"color":["，肯定会影响结果的。所以，最好使用前两种方式。

Bind 方法，进行了绑定之后，js就可以调用name方法，而这个name方法在go中的实现逻辑就是 f。

func (w *webview) Bind(name string, f interface{}) error {v := reflect.ValueOf(f)if v.Kind() != reflect.Func {return errors.New("only functions can be bound")}if n := v.Type().NumOut(); n > 2 {return errors.New("function may only return a value or a value+error")}w.m.Lock()w.bindings[name] = fw.m.Unlock()w.Init("(function() { var name = " + jsString(name) + ";" + `var RPC = window._rpc = (window._rpc || {nextSeq: 1});window[name] = function() {var seq = RPC.nextSeq++;var promise = new Promise(function(resolve, reject) {RPC[seq] = {resolve: resolve,reject: reject,};});window.external.invoke(JSON.stringify({id: seq,method: name,params: Array.prototype.slice.call(arguments),}));return promise;}})()`)return nil
}

它这里使用的是window.external.invoke()方法，即调用外部方法，因为它包装的是new Promise，所以使用 Promise 的机制来处理返回值。

在RPC调用方面，其内部机制还是postMessage()消息事件，更具体的可以阅读我关于wails的文章。

如果 Debug = true，那么按F12可以打开调试。

我的代码如下：

package mainimport ("errors""log"webview2 "github.com/jchv/go-webview2"
)func main() {w := webview2.NewWithOptions(webview2.WebViewOptions{Debug:     true,AutoFocus: true,WindowOptions: webview2.WindowOptions{Title:  "Minimal webview example",Width:  800,Height: 600,IconId: 2, // icon resource idCenter: true,},})if w == nil {log.Fatalln("Failed to load webview.")}defer w.Destroy()w.Bind("test_love", Great)w.Navigate("file:///D:/dev/php/magook/trunk/server/go-webview/test.html")w.Run()
}func Great(param string) (result string, err error) {if param == "I love you" {return "I love you too", nil} else if param == "I hate you" {return "", errors.New("break up")} else {return "I don't know", nil}
}

特别注意： Bind() 一定要在 Navigate() 之前调用，否则就是无效的！！

<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>爱吗？</title>
</head><body><div class="box"><input type="button" value="爱你" class="btn" onclick="love()"><input type="button" value="不爱了" class="btn" onclick="nolove()"></div>
</body></html>
<style>.box {margin-top: 100px;text-align: center;}.btn {display: inline-block;width: 100px;height: 50px;border-radius: 10px;border: 2px solid green;text-align: center;}
</style>
<script>function love() {window["test_love"]("I love you").then(result => {alert(result);}).catch(err => {alert(err);});}function nolove() {window["test_love"]("I hate you").then(result => {alert(result);}).catch(err => {alert(err);});}
</script>