在Visual C# .NET中建立自己的地址栏
2024-07-10 13:00:13
供稿：网友
本文内容：
概述
建立自己的地址栏
建立示例程序
最后
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概述：
本文描述了如何建立一个简单的、常用的用户控件——地址栏。
相信只要上网的朋友，都知道ie里面有一个提供大家输入你想去的网站的输入框。在该输入框中，你只需要输入部分字符，它在其下拉列表框中，就显示出来与你所输入相关的内容(记忆功能)。
如果只要求输入字符串就可以的话。那么，我们可以直接使用textbox等控件完成输入框。但如果你要让你的输入框有记忆功能的话。那么，我们所需要的就是要求能把以前所输入的内容读取出来。
好了，废话说了半天了。那么，我们从下面开始讲解如何让我们的地址栏有记忆功能的。
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建立自己的地址栏：
首先，我们要分两步走。
第一步，我们首先要明白，我们ie地址栏的历史记忆内容是从哪来的。因为只有知道它是从哪来的，我们才能明白我们的数据嘛。
那么，我们先看一下，ie在regedit(注册表)里面都有些什么内容。因为regeidt是windows里面一个非常不错的数据库(^_^)，它可以把整台机子相关的一些东西都存放在里面。
在regedit里面，与ie相关的内容有这些：
当然，这只是一部分，还有一部分是：
我们要的是第一幅图片里面的“software/microsoft/internet explorer/typedurls”的数据。不然，我们写的记忆功能就起不了什么作用了。或者，出现一些其它数据。要知道，在regedit里面保存的数据可都是一些关键数据。如果一不小心被人xx掉的话，那么，l。
ok，现在已经找到我们要的数据是从什么地方来的了。那么，我们就要开始打造我们自己的带记忆功能的地址栏了。
当然，打到这些够了吗？当然，够是够了。但，你不想让你的地址栏功能再强大一点吗？那么，我们写这样的一个类来看看：
1、 新建项目，选择新建类库，名字就顺意了。比如：controlset.urlcontrol。
2、 在资源管理里面添加引用system.windows.forms.dll。
3、 然后，在资源管理器里面把class1.cs改为unmanagedmethods.cs，然后，用下面的代码替换：
using system;
using system.runtime.interopservices;
namespace controlset.urlcontrol
{
[structlayout(layoutkind.sequential)]
internal struct rect
{
public int left;
public int top;
public int right;
public int bottom;
}
[structlayout(layoutkind.sequential)]
internal struct comboboxinfo
{
public int cbsize;
public rect rcitem;
public rect rcbutton;
public intptr statebutton;
public intptr hwndcombo;
public intptr hwndedit;
public intptr hwndlist;
}
/// <summary>
/// all unmanaged dllimport methods used in this assembly
/// </summary>
internal class unmanagedmethods
{
[dllimport("user32.dll")]
internal static extern bool getcomboboxinfo(intptr hwndcombo, ref comboboxinfo info);
[dllimport("shlwapi.dll")]
internal static extern void shautocomplete(intptr hwnd, intptr flags);
}
}
第二步，我们的地址栏出现了。那么，要用什么做为它的基控件呢？
因为我们要有记忆功能，那么，当然，要有一个能下拉的东西了。什么？combobox就是最好的选择。那好，我们开始用combobox来构建我们自己的控件。
namespace controlset.urlcontrol
{
/// <summary>
/// a control that extends the regular combo box to show urls.
/// </summary>
public class urlcombobox : combobox
{
/// <summary>
/// initilaizes a new instance of urlcombobox
/// </summary>
public urlcombobox() : base()
{
}
}
}
首先，我们添加如下引用：
using microsoft.win32;
在该控件内要用到下面一些东西，我们给它添加如下代码(添加到命名空间里面)：
/// <summary>
/// a simple enumeration that wraps various auto complete flags of shautocomplete.
/// see documenation of shautocomplete for details
/// </summary>
[flags]
public enum autocompleteflags : int
{
/// <summary>
/// this includes the file system as well as the rest of the shell (desktop/my computer/control panel/)
/// </summary>
filesystem = 0x00000001,
/// <summary>
/// urls in the user's history
/// </summary>
urlhistory = 0x00000002,
/// <summary>
/// urls in the user's recently used list.
/// </summary>
urlmru = 0x00000004,
/// <summary>
/// use the tab to move thru the autocomplete possibilities instead of to the next dialog/window control.
/// </summary>
usetab = 0x00000008,
/// <summary>
/// this includes the file system
/// </summary>
filesystemonly = 0x00000010,
/// <summary>
/// same as filesystemonly except it only includes directories, unc servers, and unc server shares.
/// </summary>
filesystemdirs = 0x00000020,
/// <summary>
/// ignore the registry default and force the auto suggest feature on.
/// </summary>
autosuggestforceon = 0x10000000,
/// <summary>
/// ignore the registry default and force the auto suggest feature off
/// </summary>
autosuggestforceoff = 0x20000000,
/// <summary>
/// ignore the registry default and force the auto append on.
/// </summary>
autoappendforceon = 0x40000000,
/// <summary>
/// ignore the registry default and force auto append off.
/// </summary>
autoappendforceoff = -2147483648
}
/// <summary>
/// enumeration for possible types of registry base keys for storing most recntly typed urls
/// </summary>
public enum mrukeyhive : int
{
/// <summary>
/// value that indicates hkey_current_user should be used for mrukey property
/// </summary>
currentuser = 1,
/// <summary>
/// value that indicates hkey_local_machine should be used for mrukey property
/// </summary>
localmachine = 2,
}
然后，再在该类里面加载如下代码来完成它应该有的功能：
/// <summary>
/// a control that extends the regular combo box to show urls.
/// </summary>
public class urlcombobox : combobox
{
/// <summary>
/// member variable which stores the autocomplete flags
/// </summary>
private autocompleteflags _flags = autocompleteflags.filesystem | autocompleteflags.urlhistory | autocompleteflags.urlmru;
/// <summary>
/// member variable which stores the mru key
/// </summary>
private string _mrukey = @"software/microsoft/internet explorer/typedurls";
/// <summary>
/// member variable which stores the mru key hive
/// </summary>
private mrukeyhive _mrukeyhive = mrukeyhive.currentuser;
/// <summary>
/// initilaizes a new instance of urlcombobox
/// </summary>
public urlcombobox() : base()
{
}
/// <summary>
/// gets the registry key where mru urls are stored
/// </summary>
/// <param name="writable">indicates whether to get the key so that it values written to it</param>
/// <returns>registrykey object for the mru registry key or null if none exists</returns>
private registrykey getmrukey(bool writable)
{
if (_mrukey.length == 0)
return null;
registrykey ret = null;
switch(_mrukeyhive)
{
case mrukeyhive.localmachine:
ret = registry.localmachine.opensubkey(_mrukey, writable);
break;
case mrukeyhive.currentuser:
ret = registry.currentuser.opensubkey(_mrukey, writable);
break;
}
return ret;
}
/// <summary>
/// writes information about any ignored exception to the trace.
/// </summary>
/// <param name="e">the exception which is being ignored</param>
private void traceignorederror(exception e)
{
//it's ok if there is any error
system.diagnostics.trace.writeline(e.message);
system.diagnostics.trace.writeline(e.stacktrace);
}
/// <summary>
/// utility function to fill the combob box most recently typed urls read from registry.
/// </summary>
private void mrufill()
{
if (designmode)
return;
registrykey mrukey = null;
try
{
int i = 1;
string strformat = "url{0}";
object defaultvalue = string.empty;
object url;
mrukey = getmrukey(false);
if (mrukey != null)
{
while((url = mrukey.getvalue(string.format(strformat, i), defaultvalue)) != defaultvalue)
{
items.add(url);
i++;
}
}
}
catch(exception e)
{
traceignorederror(e);
}
finally
{
if (mrukey != null)
mrukey.close();
}
}
/// <summary>
/// gets or sets the auto complete flags
/// </summary>
[description("gets or sets the auto complete flags")]
public autocompleteflags flags
{
get
{
return _flags;
}
set
{
_flags = value;
}
}
/// <summary>
/// gets or sets the registry key name where the combo box maintains mru list.
/// </summary>
[descriptionattribute("the registry key name where the combo box maintains mru list")]
public string mrukey
{
get
{
return _mrukey;
}
set
{
_mrukey = value;
}
}
/// <summary>
/// gets or sets the registry key hive for the mrukey property.
/// </summary>
[descriptionattribute("the registry hive where the combo box maintains mru list")]
public mrukeyhive mrukeyhive
{
get
{
return _mrukeyhive;
}
set
{
_mrukeyhive = value;
}
}
/// <summary>
/// writes the recntly typed url to the registry if it is not already there
/// </summary>
/// <param name="e"></param>
protected override void onvalidated(system.eventargs e)
{
if (designmode)
return;
if ((text.length != 0) && (items.indexof(text) == -1))
{
items.add(text);
registrykey mrukey = null;
//finally add it to the registry
try
{
mrukey = getmrukey(true);
if (mrukey != null)
mrukey.setvalue(string.format("url{0}", items.count), text);
}
catch(exception ex)
{
traceignorederror(ex);
}
finally
{
if (mrukey != null)
mrukey.close();
}
}
base.onvalidated(e);
}
/// <summary>
/// finds the handle to the edit control and calls shautocomplete on it.
/// also fills the combobox from the values read from the registry
/// </summary>
/// <param name="e">ignored</param>
protected override void onhandlecreated(system.eventargs e)
{
base.onhandlecreated(e);
if (designmode)
return;
//this is the right place do auto completion
comboboxinfo info = new comboboxinfo();
info.cbsize = system.runtime.interopservices.marshal.sizeof(info);
if (unmanagedmethods.getcomboboxinfo(handle, ref info))
{
unmanagedmethods.shautocomplete(info.hwndedit, (intptr)_flags);
}
mrufill();
}
}
好了，那么，到现在为止。我们的带记忆功能的地址栏已经构建完成。
你可以在菜单【生成(b)】里面，调试生成解决方案。
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建立示例程序：
1、 新建项目，选择windows应用程序，名称：testrulcombobox。
2、 我们把我们所需要的控件放到工具箱里面。在工具箱上面点右键。添加/移除项。打开com组件。如下图：
3、 再把我们自己写的控件也放到工具箱里面。如上图，点击里面的浏览按钮。找到你上一个解决方案存放的目录，然后，找出它所生成的动态链接库文件。就可以直接添加到工具箱上面了。
4、 在现有的项目内，把拖放刚才添加到工具箱上面的microsoft web 浏览器控件，和刚才刚才写好的控件，拖放到主窗口上面。并进行排列。
5、 添加一个控钮。
6、 双击按钮，生成事件，并在事件中输入如下代码：
cursor currentcursor = cursor.current;
try
{
cursor.current = cursors.waitcursor;
object arg1 = 0; object arg2 = ""; object arg3 = ""; object arg4 = "";
axwebbrowser1.navigate(urlcombobox1.text,ref arg1,ref arg2, ref arg3, ref arg4);
}
finally
{
cursor.current = currentcursor;
}
7、 生成解决方案。
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最后：
好了，你也可以自己试着做一个自己的、个性化的浏览器了。如果还想再加其他功能的话。那就不属于这一篇文章的目的了。j
