[MAUI]集成富文本编辑器Editor.js至.NET MAUI Blazor项目-编程知识

文章目录

- 获取资源
- - 从源码构建
  - 从CDN获取
  - 获取扩展插件
- 创建项目
- - 创建控件
  - 创建Blazor组件
  - 初始化
  - 保存
  - 销毁
  - 编写渲染逻辑
- 实现只读/编辑功能
- - 切换模式
  - 获取只读模式状态
  - 响应切换事件
- 实现明/暗主题切换
- 项目地址

Editor.js 是一个基于 Web 的所见即所得富文本编辑器，它由CodeX团队开发。之前写过一篇博文专门介绍过这个编辑器，可以回看：开源好用的所见即所得(WYSIWYG)编辑器：Editor.js。

.NET MAUI Blazor允许使用 Web UI 生成跨平台本机应用。组件在 .NET 进程中以本机方式运行，并使用本地互操作通道将 Web UI 呈现到嵌入式 Web 视图控件（BlazorWebView）。

这次我们将Editor.js集成到.NET MAUI应用中。并实现只读切换，明/暗主题切换等功能。

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使用.NET MAUI实现跨平台支持，本项目可运行于Android、iOS平台。

获取资源

我们先要获取web应用的资源文件（js，css等），以便MAUI的视图呈现标准的Web UI。有两种方式可以获取：

从源码构建
从CDN获取

从源码构建

此方法需要首先安装nodejs

克隆Editorjs项目到本地

git clone https://github.com/codex-team/editor.js.git

运行

npm i

以及

npm run build

等待nodejs构建完成，在项目根目录找到dist/editorjs.umd.js这个就是我们需要的js文件

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从CDN获取

从官方CDN获取：

https://cdn.jsdelivr.net/npm/@editorjs/editorjs@latest

获取扩展插件

Editor.js中的每个块都由插件提供。有简单的外部脚本，有自己的逻辑。默认Editor.js项目中已包含唯一的 Paragraph 块。其它的工具插件可以单独获取。

同样我们可以找到这些插件的源码编译，或通过CDN获取：

Header
链接
HTML块
简单图片（无后端要求）
图片
清单
列表
嵌入
引用

创建项目

新建.NET MAUI Blazor项目，命名Editorjs

将editorjs.umd.js和各插件js文件拷贝至项目根目录下wwwroot文件夹，文件结构如下：

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在wwwroot创建editorjs_index.html文件，并在body中引入editorjs.umd.js和各插件js文件

<body>...<script src="lib/editorjs/editorjs.umd.js"></script><script src="lib/editorjs/tools/checklist@latest.js"></script><script src="lib/editorjs/tools/code@latest.js"></script><script src="lib/editorjs/tools/delimiter@latest.js"></script><script src="lib/editorjs/tools/embed@latest.js"></script><script src="lib/editorjs/tools/header@latest.js"></script><script src="lib/editorjs/tools/image@latest.js"></script><script src="lib/editorjs/tools/inline-code@latest.js"></script><script src="lib/editorjs/tools/link@latest.js"></script><script src="lib/editorjs/tools/nested-list@latest.js"></script><script src="lib/editorjs/tools/marker@latest.js"></script><script src="lib/editorjs/tools/quote@latest.js"></script><script src="lib/editorjs/tools/table@latest.js"></script>
</body>

创建控件

创建 EditNotePage.xaml ，EditNotePage类作为视图控件，继承于ContentView，EditNotePage.xaml的完整代码如下：

<ContentView xmlns="http://schemas.microsoft.com/dotnet/2021/maui"xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"xmlns:mato="clr-namespace:Editorjs;assembly=Editorjs"xmlns:service="clr-namespace:Editorjs.ViewModels;assembly=Editorjs"xmlns:xct="http://schemas.microsoft.com/dotnet/2022/maui/toolkit"x:Name="MainPage"x:Class="Editorjs.Controls.EditNotePage"><Grid BackgroundColor="{AppThemeBinding Light={StaticResource LightPageBackgroundColor}, Dark={StaticResource DarkPageBackgroundColor}}"RowDefinitions="Auto, *, Auto"Padding="20, 10, 20, 0"><Grid Grid.Row="0"Margin="0, 0, 0, 10"><Grid.ColumnDefinitions><ColumnDefinition Width="auto"></ColumnDefinition><ColumnDefinition></ColumnDefinition><ColumnDefinition></ColumnDefinition></Grid.ColumnDefinitions><Entry Grid.Column="1"Placeholder="请输入标题"Margin="10, 0, 0, 0"VerticalOptions="Center"Text="{Binding Title}"
></Entry><HorizontalStackLayout Grid.Column="2"HeightRequest="60"VerticalOptions="Center"HorizontalOptions="End"Margin="0, 0, 10, 0"><StackLayout RadioButtonGroup.GroupName="State"RadioButtonGroup.SelectedValue="{Binding NoteSegmentState,Mode=TwoWay}"Orientation="Horizontal"><RadioButton Value="{x:Static service:NoteSegmentState.Edit}"Content="编辑"></RadioButton><RadioButton Value="{x:Static service:NoteSegmentState.PreView}"Content="预览"></RadioButton></StackLayout></HorizontalStackLayout></Grid><BlazorWebView Grid.Row="1"Margin="-10, 0"x:Name="mainMapBlazorWebView"HostPage="wwwroot/editorjs_index.html"><BlazorWebView.RootComponents><RootComponent Selector="#app"x:Name="rootComponent"ComponentType="{x:Type mato:EditorjsPage}" /></BlazorWebView.RootComponents></BlazorWebView><ActivityIndicator Grid.RowSpan="4"IsRunning="{Binding Loading}"></ActivityIndicator></Grid>
</ContentView>

创建一个EditNotePageViewModel的ViewModel类，用于处理页面逻辑。代码如下：

public class EditNotePageViewModel : ObservableObject, IEditorViewModel
{public Func<Task<string>> OnSubmitting { get; set; }public Action<string> OnInited { get; set; }public Action OnFocus { get; set; }public EditNotePageViewModel(){Submit = new Command(SubmitAction);NoteSegmentState=NoteSegmentState.Edit;var content = "";using (Stream stream = Assembly.GetExecutingAssembly().GetManifestResourceStream("Editorjs.Assets.sample1.json")){if (stream != null){using (StreamReader reader = new StreamReader(stream)){content = reader.ReadToEnd();                     }}}Init(new Note(){Title = "sample",Content=content});}private void Init(Note note){if (note != null){Title = note.Title;Content = note.Content;}OnInited?.Invoke(this.Content);}private string _title;public string Title{get { return _title; }set{_title = value;OnPropertyChanged();}}private string _content;public string Content{get { return _content; }set{_content = value;OnPropertyChanged();}}private async void SubmitAction(object obj){var savedContent = await OnSubmitting?.Invoke();if (string.IsNullOrEmpty(savedContent)){return;}this.Content=savedContent;var note = new Note();note.Title = this.Title;note.Content = this.Content;}public Command Submit { get; set; }}

注意这里的Init方法，用于初始化内容。这里我们读取Editorjs.Assets.sample1.json资源文件作为初始内容。

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创建Blazor组件

创建Blazor页面EditorjsPage.razor

在EditorjsPage.razor页面中，我们放置一个div，用于放置编辑器，

razor页面的 @Code 代码段中，放置EditNotePageViewModel属性，以及一个DotNetObjectReference对象，用于在JS中调用C#方法。

@code {[Parameter]public IEditorViewModel EditNotePageViewModel { get; set; }private DotNetObjectReference<EditorjsPage> objRef;protected override void OnInitialized(){objRef = DotNetObjectReference.Create(this);}

初始化

在script代码段中，创建LoadContent函数，用于加载EditorJs的初始内容。

<div class="ce-main"><div id="editorjs"></div>
</div>

LoadContent中，调用函数window.editor = new window.EditorJS(config)创建一个EditorJS对象，其中config对象包括holder，tools，data等属性，关于EditorJs配置的更多说明请参考官方文档

<script type="text/javascript">window.editor = null;window.viewService = {LoadContent: function (content) {var obj = JSON.parse(content);var createEdtor = () => {window.editor = new window.EditorJS({                 holder: 'editorjs',/*** Tools list*/tools: {paragraph: {config: {placeholder: "Enter something"}},header: {class: Header,inlineToolbar: ['link'],config: {placeholder: 'Header'},shortcut: 'CMD+SHIFT+H'},/*** Or pass class directly without any configuration*/image: {class: ImageTool},list: {class: NestedList,inlineToolbar: true,shortcut: 'CMD+SHIFT+L'},checklist: {class: Checklist,inlineToolbar: true,},quote: {class: Quote,inlineToolbar: true,config: {quotePlaceholder: '输入引用内容',captionPlaceholder: '引用标题',},shortcut: 'CMD+SHIFT+O'},marker: {class: Marker,shortcut: 'CMD+SHIFT+M'},code: {class: CodeTool,shortcut: 'CMD+SHIFT+C'},delimiter: Delimiter,inlineCode: {class: InlineCode,shortcut: 'CMD+SHIFT+C'},linkTool: LinkTool,embed: Embed,table: {class: Table,inlineToolbar: true,shortcut: 'CMD+ALT+T'},},i18n: {messages: {"ui": {"blockTunes": {"toggler": {"Click to tune": "点击转换","or drag to move": "拖动调整"},},"inlineToolbar": {"converter": {"Convert to": "转换成"}},"toolbar": {"toolbox": {"Add": "添加","Filter": "过滤","Nothing found": "无内容"},"popover": {"Filter": "过滤","Nothing found": "无内容"}}},"toolNames": {"Text": "段落","Heading": "标题","List": "列表","Warning": "警告","Checklist": "清单","Quote": "引用","Code": "代码","Delimiter": "分割线","Raw HTML": "HTML片段","Table": "表格","Link": "链接","Marker": "突出显示","Bold": "加粗","Italic": "倾斜","InlineCode": "代码片段","Image": "图片"},"tools": {"link": {"Add a link": "添加链接"},"stub": {'The block can not be displayed correctly.': '该模块不能放置在这里'},"image": {"Caption": "图片说明","Select an Image": "选择图片","With border": "添加边框","Stretch image": "拉伸图像","With background": "添加背景",},"code": {"Enter a code": "输入代码",},"linkTool": {"Link": "请输入链接地址","Couldn't fetch the link data": "获取链接数据失败","Couldn't get this link data, try the other one": "该链接不能访问，请修改","Wrong response format from the server": "错误响应",},"header": {"Header": "标题","Heading 1": "一级标题","Heading 2": "二级标题","Heading 3": "三级标题","Heading 4": "四级标题","Heading 5": "五级标题","Heading 6": "六级标题",},"paragraph": {"Enter something": "请输入笔记内容",},"list": {"Ordered": "有序列表","Unordered": "无序列表",},"table": {"Heading": "标题","Add column to left": "在左侧插入列","Add column to right": "在右侧插入列","Delete column": "删除列","Add row above": "在上方插入行","Add row below": "在下方插入行","Delete row": "删除行","With headings": "有标题","Without headings": "无标题",},"quote": {"Align Left": "左对齐","Align Center": "居中对齐",}},"blockTunes": {"delete": {"Delete": "删除",'Click to delete': "点击删除"},"moveUp": {"Move up": "向上移"},"moveDown": {"Move down": "向下移"},"filter": {"Filter": "过滤"}},}},/*** Initial Editor data*/data: obj});}if (window.editor) {editor.isReady.then(() => {editor.destroy();createEdtor();});}else {createEdtor();}},DumpContent: async function () {outputData = null;if (window.editor) {if (window.editor.readOnly.isEnabled) {await window.editor.readOnly.toggle();}var outputObj = await window.editor.save();outputData = JSON.stringify(outputObj);}return outputData;},SwitchTheme: function () {document.body.classList.toggle("dark-mode");},SwitchState: async function () {state = null;if (window.editor && window.editor.readOnly) {var readOnlyState = await window.editor.readOnly.toggle();state = readOnlyState;}return state;},Focus: async function (atEnd) {if (window.editor) {await window.editor.focus(atEnd);}},GetState() {if (window.editor && window.editor.readOnly) {return window.editor.readOnly.isEnabled;}},Destroy: function () {if (window.editor) {window.editor.destroy();}},}window.initObjRef = function (objRef) {window.objRef = objRef;}</script>

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保存

创建转存函数DumpContent

DumpContent: async function () {outputData = null;if (window.editor) {if (window.editor.readOnly.isEnabled) {await window.editor.readOnly.toggle();}var outputObj = await window.editor.save();outputData = JSON.stringify(outputObj);}return outputData;
},

销毁

创建销毁函数Destroy


Destroy: function () {if (window.editor) {window.editor.destroy();}
},

编写渲染逻辑

在OnAfterRenderAsync中调用初始化函数，并订阅OnSubmitting和OnInited事件，以便在提交事件触发时保存，以及文本状态变更时重新渲染。

 protected override async Task OnAfterRenderAsync(bool firstRender){if (!firstRender)return;if (EditNotePageViewModel != null){EditNotePageViewModel.PropertyChanged += EditNotePageViewModel_PropertyChanged;this.EditNotePageViewModel.OnSubmitting += OnSubmitting;this.EditNotePageViewModel.OnInited += OnInited;var currentContent = EditNotePageViewModel.Content;await JSRuntime.InvokeVoidAsync("viewService.LoadContent", currentContent);}await JSRuntime.InvokeVoidAsync("window.initObjRef", this.objRef);}

private async Task<string> OnSubmitting()
{var savedContent = await JSRuntime.InvokeAsync<string>("viewService.DumpContent");return savedContent;
}private async void OnInited(string content)
{await JSRuntime.InvokeVoidAsync("viewService.LoadContent", content);
}

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实现只读/编辑功能

在.NET本机中，我们使用枚举来表示编辑状态。并在控件上设置一个按钮来切换编辑状态。

public enum NoteSegmentState
{Edit,PreView
}

EditNotePageViewModel.cs:

...
private NoteSegmentState _noteSegmentState;public NoteSegmentState NoteSegmentState{get { return _noteSegmentState; }set{_noteSegmentState = value;OnPropertyChanged();}}

EditNotePage.xaml:

...
<StackLayout RadioButtonGroup.GroupName="State"RadioButtonGroup.SelectedValue="{Binding NoteSegmentState,Mode=TwoWay}"Orientation="Horizontal"><RadioButton Value="{x:Static service:NoteSegmentState.Edit}"Content="编辑"></RadioButton><RadioButton Value="{x:Static service:NoteSegmentState.PreView}"Content="预览"></RadioButton></StackLayout>

Editorjs官方提供了readOnly对象，通过toggle()方法，可以切换编辑模式和只读模式。

在创建Editorjs实例时，也可以通过设置readOnly属性为true即可实现只读模式。

切换模式

在razor页面中创建SwitchState函数，用来切换编辑模式和只读模式。

SwitchState: async function () {state = null;if (window.editor && window.editor.readOnly) {var readOnlyState = await window.editor.readOnly.toggle();state = readOnlyState;}return state;
},

获取只读模式状态

在razor页面中创建GetState函数，用来获取编辑模式和只读模式的状态。


GetState() {if (window.editor && window.editor.readOnly) {return window.editor.readOnly.isEnabled;}
},

响应切换事件

我们监听EditNotePageViewModel 的NoteSegmentState属性变更事件，当状态改变时，调用对应的js方法

private async void EditNotePageViewModel_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
{if (e.PropertyName == nameof(EditNotePageViewModel.NoteSegmentState)){if (EditNotePageViewModel.NoteSegmentState==NoteSegmentState.PreView){var state = await JSRuntime.InvokeAsync<bool>("viewService.GetState");if (!state){await JSRuntime.InvokeAsync<bool>("viewService.SwitchState");}}else if (EditNotePageViewModel.NoteSegmentState==NoteSegmentState.Edit){var state = await JSRuntime.InvokeAsync<bool>("viewService.GetState");if (state){await JSRuntime.InvokeAsync<bool>("viewService.SwitchState");}}}
}

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实现明/暗主题切换

lib/editorjs/css/main.css中，定义了.dark-mode类的样式表

.dark-mode {
--color-border-light: rgba(255, 255, 255,.08);
--color-bg-main: #212121;
--color-text-main: #F5F5F5;
}.dark-mode .ce-popover {--color-background: #424242;--color-text-primary: #F5F5F5;--color-text-secondary: #707684;--color-border: #424242;
}.dark-mode .ce-toolbar__settings-btn {background: #2A2A2A;border: 1px solid #424242;
}.dark-mode .ce-toolbar__plus {background: #2A2A2A;border: 1px solid #424242;
}.dark-mode .ce-popover-item__icon {background: #2A2A2A;
}.dark-mode .ce-code__textarea {color: #212121;background: #2A2A2A;
}.dark-mode .tc-popover {--color-border: #424242;--color-background: #424242;
}
.dark-mode .tc-wrap {--color-background: #424242;
}

在razor页面中添加SwitchTheme函数，用于用于切换dark-mode"的`类名，从而实现暗黑模式和正常模式之间的切换。

SwitchTheme: function () {document.body.classList.toggle("dark-mode");
},

在OnInitializedAsync中，订阅Application.Current.RequestedThemeChanged事件，用于监听主题切换事件，并调用SwitchTheme函数。

protected override async Task OnInitializedAsync()
{objRef = DotNetObjectReference.Create(this);Application.Current.RequestedThemeChanged += OnRequestedThemeChanged;}
private async void OnRequestedThemeChanged(object sender, AppThemeChangedEventArgs args)
{await JSRuntime.InvokeVoidAsync("viewService.SwitchTheme");
}

在渲染页面时，也判断是否需要切换主题

protected override async Task OnAfterRenderAsync(bool firstRender)
{if (!firstRender)return;···if (Application.Current.UserAppTheme==AppTheme.Dark){await JSRuntime.InvokeVoidAsync("viewService.SwitchTheme");}}

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