WebView2控件应用详解系列博客
.NET混合开发解决方案2 WebView2与Edge浏览器的区别
.NET混合开发解决方案5 WebView2运行时与分发应用
.NET混合开发解决方案7 WinForm程序中通过NuGet管理器引用集成WebView2控件
.NET混合开发解决方案8 WinForm程序中通过设置固定版本运行时的BrowserExecutableFolder属性集成WebView2控件
在我的博客《.NET混合开发解决方案7 WinForm程序中集成WebView2》中介绍了WinForm程序中集成WebView2组件的详细步骤以及注意事项。这只是最基本的应用，WebView2功能之所以强大，是因为它提供了很多开放的属性与事件供开发者调用以完成复杂的功能。具体可以参考我的博客《.NET混合开发解决方案2 WebView2与Edge浏览器的区别》。
本文介绍WebView2应用程序的导航事件。当WebView2实例中显示的内容发生特定的异步操作时，导航事件会运行。例如，当WebView2用户导航到新网站时，本机内容（WinForm、WPF、Win32、WinUI）通过侦听 NavigationStarting 事件来侦听更改。导航操作完成后，NavigationCompleted 事件将运行。
导航事件的正常顺序为：
以下事件描述每次导航操作期间 WebView2 的状态：
上图显示了在各自的事件参数上具有相同NavigationId属性的导航事件。
当在文本框中输入目标网址后，点击【导航】按钮，具体执行逻辑如下
发生错误时，会引发以下事件，这可能取决于对错误网页的导航：
SourceChangedContentLoadingHistoryChanged如果发生HTTP重定向，则一行中有多个NavigationStarting事件。
先看一个效果动画
逻辑代码
1 public partial class Frm2Navigation : Form 2 { 3 public Frm2Navigation() 4 { 5 InitializeComponent(); 6 7 InitializeAsync(); 8 9 webView2.CoreWebView2InitializationCompleted += WebView2_CoreWebView2InitializationCompleted; 10 11 webView2.NavigationStarting += WebView2_NavigationStarting; 12 webView2.NavigationCompleted += WebView2_NavigationCompleted; 13 } 14 15 async void InitializeAsync() 16 { 17 await webView2.EnsureCoreWebView2Async(null); 18 } 19 20 private void WebView2_CoreWebView2InitializationCompleted(object? sender, CoreWebView2InitializationCompletedEventArgs e) 21 { 22 if (e.IsSuccess == false) 23 { 24 MessageBox.Show("WebView2_CoreWebView2InitializationCompleted 事件，发生异常。" 25 + Environment.NewLine + e.InitializationException.Message, 26 "提示", MessageBoxButtons.OK, MessageBoxIcon.Error); 27 } 28 29 webView2.SourceChanged += WebView2_SourceChanged; 30 webView2.ContentLoading += WebView2_ContentLoading; 31 webView2.CoreWebView2.HistoryChanged += CoreWebView2_HistoryChanged; 32 webView2.CoreWebView2.DOMContentLoaded += CoreWebView2_DOMContentLoaded; 33 34 webView2.CoreWebView2.BasicAuthenticationRequested += CoreWebView2_BasicAuthenticationRequested; 35 webView2.CoreWebView2.ProcessFailed += CoreWebView2_ProcessFailed; 36 } 37 38 private void WebView2_NavigationStarting(object? sender, CoreWebView2NavigationStartingEventArgs e) 39 { 40 string uri = e.Uri; 41 if (!uri.StartsWith("https://")) 42 { 43 //webView2.CoreWebView2.ExecuteScriptAsync($"alert('{uri} 不安全, 请尝试https链接。')"); 44 45 DialogResult dr = MessageBox.Show($"{uri} 不安全, 请尝试https链接。rnrn 确定要访问吗？", "提示", MessageBoxButtons.OKCancel, MessageBoxIcon.Warning); 46 if (dr == DialogResult.Cancel) 47 { 48 e.Cancel = true; 49 } 50 } 51 } 52 53 private void WebView2_SourceChanged(object? sender, CoreWebView2SourceChangedEventArgs e) 54 { 55 //if(e.IsNewDocument) 56 //{ 57 // webView2.CoreWebView2.ExecuteScriptAsync("alert('WebView2_SourceChanged事件。= e.IsNewDocument = true')"); 58 //} 59 60 MessageBox.Show("WebView2_SourceChanged 事件。" 61 + Environment.NewLine + "e.IsNewDocument = " + e.IsNewDocument, 62 "提示", MessageBoxButtons.OK, MessageBoxIcon.Information); 63 } 64 65 private void WebView2_ContentLoading(object? sender, CoreWebView2ContentLoadingEventArgs e) 66 { 67 //webView2.CoreWebView2.ExecuteScriptAsync("alert('WebView2_SourceChanged事件。= e.IsNewDocument = true')"); 68 69 MessageBox.Show("WebView2_ContentLoading 事件。" 70 + Environment.NewLine + "e.IsErrorPage = " + e.IsErrorPage, 71 "提示", MessageBoxButtons.OK, MessageBoxIcon.Information); 72 } 73 74 private void CoreWebView2_HistoryChanged(object? sender, object e) 75 { 76 MessageBox.Show("CoreWebView2_HistoryChanged 事件。", 77 "提示", MessageBoxButtons.OK, MessageBoxIcon.Information); 78 } 79 80 private void CoreWebView2_DOMContentLoaded(object? sender, CoreWebView2DOMContentLoadedEventArgs e) 81 { 82 MessageBox.Show("CoreWebView2_DOMContentLoaded 事件。" 83 + Environment.NewLine + "e.NavigationId = " + e.NavigationId, 84 "提示", MessageBoxButtons.OK, MessageBoxIcon.Information); 85 } 86 87 private void WebView2_NavigationCompleted(object? sender, CoreWebView2NavigationCompletedEventArgs e) 88 { 89 MessageBox.Show("WebView2_NavigationCompleted 事件。" 90 + Environment.NewLine + "e.NavigationId = " + e.NavigationId 91 + Environment.NewLine + "e.IsSuccess = " + e.IsSuccess 92 + Environment.NewLine + "e.WebErrorStatus = " + e.WebErrorStatus, 93 "提示", MessageBoxButtons.OK, MessageBoxIcon.Information); 94 } 95 96 97 private void CoreWebView2_ProcessFailed(object? sender, CoreWebView2ProcessFailedEventArgs e) 98 { 99 MessageBox.Show("CoreWebView2_ProcessFailed 事件。" 100 + Environment.NewLine + "e.ExitCode = " + e.ExitCode 101 + Environment.NewLine + "e.FrameInfosForFailedProcess = " + e.FrameInfosForFailedProcess 102 + Environment.NewLine + "e.ProcessDescription = " + e.ProcessDescription 103 + Environment.NewLine + "e.ProcessFailedKind = " + e.ProcessFailedKind 104 + Environment.NewLine + "e.Reason = " + e.Reason, 105 "提示", MessageBoxButtons.OK, MessageBoxIcon.Information); 106 } 107 108 109 private void CoreWebView2_BasicAuthenticationRequested(object? sender, CoreWebView2BasicAuthenticationRequestedEventArgs e) 110 { 111 MessageBox.Show("CoreWebView2_BasicAuthenticationRequested 事件。" 112 + Environment.NewLine + "e.Uri = " + e.Uri 113 + Environment.NewLine + "e.Cancel = " + e.Cancel 114 + Environment.NewLine + "e.Challenge = " + e.Challenge 115 + Environment.NewLine + "e.Response = " + e.Response, 116 "提示", MessageBoxButtons.OK, MessageBoxIcon.Information); 117 118 } 119 120 121 // 访问url 122 private void btnGo_Click(object sender, EventArgs e) 123 { 124 string rawUrl = txtUrl.Text; 125 if (string.IsNullOrWhiteSpace(rawUrl)) 126 { 127 MessageBox.Show("请输入网址。", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning); 128 129 txtUrl.Focus(); 130 131 return; 132 } 133 134 Uri uri; 135 136 if (Uri.IsWellFormedUriString(rawUrl, UriKind.Absolute)) 137 { 138 uri = new Uri(rawUrl); 139 } 140 else if (rawUrl.Contains(" ") == false && rawUrl.Contains(".") == false) 141 { 142 // 无效的URI包含一个点且没有空格，请尝试在前面添加http://标记 143 uri = new Uri("http://" + rawUrl); 144 } 145 else if (rawUrl.StartsWith("http://") == false) 146 { 147 uri = new Uri("http://" + rawUrl); 148 } 149 else 150 { 151 // 其他情况将其视为网络搜索 152 uri = new Uri("https://bing.com/search?q=" + string.Join("+", Uri.EscapeDataString(rawUrl).Split(new string[] { "%20" }, StringSplitOptions.RemoveEmptyEntries))); 153 } 154 155 //webView2.CoreWebView2.Navigate(url.Trim()); 156 webView2.Source = uri; 157 } 158 }
注意事项
CoreWebview2的相关事件必须在它的 CoreWebView2InitializationCompleted 事件（CoreWebView2对象初始化完成后事件）里面注册
如上第31、32、34、35行。
