Question

我在窗体表单app中使用WebBrowser控件。应用程序定期抓取网站（使用计时器），然后在WebBrowser中显示汇总版本。我使用DocumentText属性使用字符串加载WebBrowser。

所有工作都非常好，除了当我加载WebBrowser时它会发出哔哔声，而不是第一次，而是在后续加载时。我不知道它为什么会发出哔哔声，也许还有一些不太符合html规范的东西。但它看起来还不错，即使WebBrowser发现错误，我也不希望它发出蜂鸣声。

如何防止WebBrowser发出哔哔声？

Answer 1

尝试创建自己的WebBrowser控件，如下所示。 SafeWebBrowser是一个WebBrowser派生的Control，它不允许脚本或activeX控件执行。它还可以防止显示WebBrowser的上下文菜单。不确定这是否会阻止嘟嘟声，但试一试。

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Windows.Forms;

/// <summary>
/// Stole code from http://stackoverflow.com/questions/7608550/implement-idispatchinvoke-to-be-called-by-a-webbrowser-control
/// </summary>
public class SafeWebBrowser : WebBrowser
{
    private const int DISPID_AMBIENT_DLCONTROL = -5512;
    private int _downloadControlFlags;

    protected override void OnHandleCreated( EventArgs e )
    {
        base.OnHandleCreated( e );

        // Here is where the magic happens.
        // Disable java, scripts, activeX controls, etc.
        //

        DownloadControlFlags = ( int )(
            WebBrowserDownloadControlFlags.NO_JAVA
            | WebBrowserDownloadControlFlags.NO_BEHAVIORS
            | WebBrowserDownloadControlFlags.NO_DLACTIVEXCTLS
            | WebBrowserDownloadControlFlags.NO_RUNACTIVEXCTLS
            | WebBrowserDownloadControlFlags.NO_SCRIPTS
            | WebBrowserDownloadControlFlags.PRAGMA_NO_CACHE
            | WebBrowserDownloadControlFlags.SILENT
            | WebBrowserDownloadControlFlags.DLIMAGES
        );

        // Disable the context menu.
        //

        this.IsWebBrowserContextMenuEnabled = false;
    }

    // we want our site class, not the default one
    protected override WebBrowserSiteBase CreateWebBrowserSiteBase()
    {
        return new MyWebBrowserSite( this );
    }

    [DispId( DISPID_AMBIENT_DLCONTROL )]
    private int DownloadControlFlags
    {
        get
        {
            return _downloadControlFlags;
        }
        set
        {
            if ( _downloadControlFlags == value )
                return;

            _downloadControlFlags = value;
            IOleControl ctl = ( IOleControl )ActiveXInstance;
            ctl.OnAmbientPropertyChange( DISPID_AMBIENT_DLCONTROL );
        }
    }

    private class MyWebBrowserSite : WebBrowserSite, IReflect
    {
        private Dictionary<int, PropertyInfo> _dispidCache;
        private SafeWebBrowser _host;

        public MyWebBrowserSite( SafeWebBrowser host )
            : base( host )
        {
            _host = host;
        }

        object IReflect.InvokeMember( string name, BindingFlags invokeAttr, Binder binder, object target, object[] args, ParameterModifier[] modifiers, CultureInfo culture, string[] namedParameters )
        {
            object ret = null;
            // Check direct IDispatch call using a dispid (see http://msdn.microsoft.com/en-us/library/de3dhzwy.aspx)
            const string dispidToken = "[DISPID=";
            if ( name.StartsWith( dispidToken ) )
            {
                int dispid = int.Parse( name.Substring( dispidToken.Length, name.Length - dispidToken.Length - 1 ) );
                if ( _dispidCache == null )
                {
                    // WebBrowser has many properties, so we build a dispid cache on it
                    _dispidCache = new Dictionary<int, PropertyInfo>();
                    foreach ( PropertyInfo pi in _host.GetType().GetProperties( BindingFlags.Public | BindingFlags.Instance ) )
                    {
                        if ( ( !pi.CanRead ) || ( pi.GetIndexParameters().Length > 0 ) )
                            continue;

                        object[] atts = pi.GetCustomAttributes( typeof( DispIdAttribute ), true );
                        if ( ( atts != null ) && ( atts.Length > 0 ) )
                        {
                            DispIdAttribute da = ( DispIdAttribute )atts[ 0 ];
                            _dispidCache[ da.Value ] = pi;
                        }
                    }
                }

                PropertyInfo property;
                if ( _dispidCache.TryGetValue( dispid, out property ) )
                {
                    ret = property.GetValue( _host, null );
                }
            }
            return ret;
        }

        FieldInfo[] IReflect.GetFields( BindingFlags bindingAttr )
        {
            return GetType().GetFields( bindingAttr );
        }

        MethodInfo[] IReflect.GetMethods( BindingFlags bindingAttr )
        {
            return GetType().GetMethods( bindingAttr );
        }

        PropertyInfo[] IReflect.GetProperties( BindingFlags bindingAttr )
        {
            return GetType().GetProperties( bindingAttr );
        }

        FieldInfo IReflect.GetField( string name, BindingFlags bindingAttr )
        {
            throw new NotImplementedException();
        }

        MemberInfo[] IReflect.GetMember( string name, BindingFlags bindingAttr )
        {
            throw new NotImplementedException();
        }

        MemberInfo[] IReflect.GetMembers( BindingFlags bindingAttr )
        {
            throw new NotImplementedException();
        }

        MethodInfo IReflect.GetMethod( string name, BindingFlags bindingAttr )
        {
            throw new NotImplementedException();
        }

        MethodInfo IReflect.GetMethod( string name, BindingFlags bindingAttr, Binder binder, Type[] types, ParameterModifier[] modifiers )
        {
            throw new NotImplementedException();
        }

        PropertyInfo IReflect.GetProperty( string name, BindingFlags bindingAttr, Binder binder, Type returnType, Type[] types, ParameterModifier[] modifiers )
        {
            throw new NotImplementedException();
        }

        PropertyInfo IReflect.GetProperty( string name, BindingFlags bindingAttr )
        {
            throw new NotImplementedException();
        }

        Type IReflect.UnderlyingSystemType
        {
            get { throw new NotImplementedException(); }
        }
    }

    [ComImport, InterfaceType( ComInterfaceType.InterfaceIsIUnknown ), Guid( "B196B288-BAB4-101A-B69C-00AA00341D07" )]
    private interface IOleControl
    {
        void Reserved0();
        void Reserved1();
        void OnAmbientPropertyChange( int dispID );
        void Reserved2();
    }

    [Flags]
    enum WebBrowserDownloadControlFlags : uint
    {
        DLIMAGES = 0x00000010,
        VIDEOS = 0x00000020,
        BGSOUNDS = 0x00000040,
        NO_SCRIPTS = 0x00000080,
        NO_JAVA = 0x00000100,
        NO_RUNACTIVEXCTLS = 0x00000200,
        NO_DLACTIVEXCTLS = 0x00000400,
        DOWNLOADONLY = 0x00000800,
        NO_FRAMEDOWNLOAD = 0x00001000,
        RESYNCHRONIZE = 0x00002000,
        PRAGMA_NO_CACHE = 0x00004000,
        NO_BEHAVIORS = 0x00008000,
        NO_METACHARSET = 0x00010000,
        URL_ENCODING_DISABLE_UTF8 = 0x00020000,
        URL_ENCODING_ENABLE_UTF8 = 0x00040000,
        NOFRAMES = 0x00080000,
        FORCEOFFLINE = 0x10000000,
        NO_CLIENTPULL = 0x20000000,
        SILENT = 0x40000000,
        OFFLINEIFNOTCONNECTED = 0x80000000,
        OFFLINE = OFFLINEIFNOTCONNECTED,
    }
}

防止WebBrowser控件在winforms中加载时发出蜂鸣声

1 个答案: