100165777.htm
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<p class=MsoNormal style='line-height:15.6pt'><span style='font-family:宋体'>因为要读取每个值，所以</span><span
lang=EN-US>ReadSettings()</span><span style='font-family:宋体'>方法比较长，在此还需解释它，在列表框中显示它，并对主窗体的相应属性进行适当的调整。</span><span
lang=EN-US>ReadSettings()</span><span style='font-family:宋体'>如下所示。</span></p>
<p class=2 style='margin-top:8.15pt;margin-right:0cm;FTEL:0cm;
margin-left:21.45pt;FTEL:.0001pt;FTEL:18.45pt'><span
lang=EN-US> bool ReadSettings()</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
{ </span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
RegistryKey softwareKey = </span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
Registry.LocalMachine.OpenSubKey("Software");</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
RegistryKey wroxKey = softwareKey.OpenSubKey("<span style='letter-spacing:
.1pt'>Wrox</span>Press");</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
if (wroxKey == null)</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
return false;</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
RegistryKey selfPlacingWindowKey = </span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
wroxKey.OpenSubKey("SelfPlacingWindow");</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
if (selfPlacingWindowKey == null)</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
return false;</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
else</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
listBoxMessages.Items.Add("Successfully opened key " + </span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
selfPlacingWindowKey.ToString());</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
int redComponent = (int)selfPlacingWindowKey.GetValue("Red");</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
int greenComponent = (int)selfPlacingWindowKey.GetValue("Green");</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
int blueComponent = (int)selfPlacingWindowKey.GetValue("Blue");</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
this.BackColor = Color.FromArgb(redComponent, greenComponent, </span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
blueComponent);</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
listBoxMessages.Items.Add("Background color: " + BackColor.Name);</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
int X = (int)selfPlacingWindowKey.GetValue("X");</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
int Y = (int)selfPlacingWindowKey.GetValue("Y");</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
this.DesktopLocation = new Point(X, Y);</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
listBoxMessages.Items.Add("Desktop location: " + </span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
DesktopLocation.ToString());</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
this.Height = (int)selfPlacingWindowKey.GetValue("Height");</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
this.Width = (int)selfPlacingWindowKey.GetValue("Width");</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
listBoxMessages.Items.Add("Size: " + new </span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
Size(Width,Height).ToString());</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
string initialWindowState = </span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
(string)selfPlacingWindowKey.GetValue("WindowState");</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
listBoxMessages.Items.Add("Window State: " + initialWindowState);</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
this.WindowState = (FormWindowState)FormWindowState.Parse</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
(WindowState.GetType(), initialWindowState);</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
return true;</span></p>
<p class=2 style='margin-top:0cm;margin-right:0cm;FTEL:8.15pt;
margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
}</span></p>
<p class=MsoNormal style='line-height:15.0pt'><span style='font-family:宋体'>在</span><span
lang=EN-US>ReadSettings()</span><span style='font-family:宋体'>中，首先浏览</span><span
lang=EN-US>HKLM/Software/WroxPress/SelfPlacingWindow</span><span
style='font-family:宋体'>注册表项，但在本例中，要找到这个键，才能读取其中的内容。如果它不存在，在第一次运行示例时才会创建它。本例将停止读取键，而且不打算创建任何键。现在使用</span><span
lang=EN-US>RegistryKey.OpenSubkey()</span><span style='font-family:宋体'>方法。如果</span><span
lang=EN-US>OpenSubkey()</span><span style='font-family:宋体'>返回空引用，就表示该注册表项不存在，因此只能给调用代码返回</span><span
lang=EN-US>false</span><span style='font-family:宋体'>值。</span></p>
<p class=MsoNormal style='line-height:15.0pt'><span style='font-family:宋体'>在读取该键时，使用了</span><span
lang=EN-US>RegistryKey.GetValue()</span><span style='font-family:宋体'>方法，该方法返回一个对象引用，这表示这个方法可以返回任何类的实例。与</span><span
lang=EN-US>SetValue()</span><span style='font-family:宋体'>一样，它返回对应于键中数据类型的对象类，这样就可以假定</span><span
lang=EN-US>REG</span><span lang=EN-US style='font-family:"Baskerville BE Regular"'>_</span><span
lang=EN-US>SZ</span><span style='font-family:宋体'>键会提供一个字符串，其他键会提供一个整数。另外，还要转换</span><span
lang=EN-US>SetValue()</span><span style='font-family:宋体'>返回的引用。如果引发了异常，就说明有人打开了注册表，且改变了值的类型，因此这种转换就会引发异常，</span><span
lang=EN-US>Form1</span><span style='font-family:宋体'>构造函数中的处理程序会捕获该异常。</span></p>
<p class=MsoNormal style='line-height:15.0pt'><span style='font-family:宋体'>这段代码的其余部分还使用了一个数据类型</span><span
lang=EN-US>Size</span><span style='font-family:宋体'>结构，</span><span lang=EN-US>Size</span><span
style='font-family:宋体'>结构类似于</span><span lang=EN-US>Point</span><span
style='font-family:宋体'>结构，但用于表示大小，而不是坐标。它有两个成员属性</span><span lang=EN-US>Width </span><span
style='font-family:宋体'>和</span><span lang=EN-US> Height</span><span
style='font-family:宋体'>，使用</span><span lang=EN-US>Size</span><span
style='font-family:宋体'>结构便于确定在列表框中显示的窗体的大小。</span></p>
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<h1 id="divCurrentNode2" style="color: #b83507; width: 100%; text-align: left; font-size: 12px; padding-left: 2px">当前章节:<a href='100165777.htm'><font color='red'>30.4.3 SelfPlacingWindow示例</font></a></h1>
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<div style='float:left;width:49%'>·<a href='100165774.htm'>30.4 读写注册表</a></div><div style='float:right;width:49%'>·<a href='100165775.htm'>30.4.1 注册表</a></div><div style='float:left;width:49%'>·<a href='100165776.htm'>30.4.2 .NET注册表类</a></div><div style='float:right;width:49%'>·<a href='100165778.htm'>30.5 小结</a></div><div style='float:left;width:49%'>·<a href='100165779.htm'>31.1 WebClient类</a></div><div style='float:right;width:49%'>·<a href='100165780.htm'>31.1.1 下载文件</a></div></div>
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