题
此代码旨在对一列十进制值求和，但在int.Parse()行引发异常。请参阅本文末尾附近有关如何修改代码以更正此错误以及我通过该尝试收到的错误。
static void Main()
{
String htmlFile = "C:/Temp/Test11.html";
HtmlDocument doc = new HtmlDocument();
doc.Load(htmlFile);
// Site Collection Storage Used (GB)
var sum = doc.DocumentNode.SelectSingleNode("//table")
// The sum will be of the row elements
.Elements("tr")
// Skip this many rows from the top
.Skip(1)
// .ElementAt(2) = third column
// .Last() = last column
.Sum(tr => int.Parse(tr.Elements("td").ElementAt(3).InnerText));
Console.WriteLine("Site Collection Storage Used (GB): " + sum);
Console.ReadLine();
}
这是例外：
System.FormatException was unhandled
HResult=-2146233033
Message=Input string was not in a correct format.
Source=mscorlib
StackTrace:
at System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal)
at System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info)
at System.Int32.Parse(String s)
at ValueSpecifiedCellSpecifiedTable.Program.<Main>b__2(HtmlNode tr) in c:\Users\User1\Documents\Visual Studio 2012\Projects\_ValueSpecifiedCellSpecifiedTable\ValueSpecifiedCellSpecifiedTable\Program.cs:line 92
at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
at System.Linq.Enumerable.Sum(IEnumerable`1 source)
at System.Linq.Enumerable.Sum[TSource](IEnumerable`1 source, Func`2 selector)
at ValueSpecifiedCellSpecifiedTable.Program.Main() in c:\Users\User1\Documents\Visual Studio 2012\Projects \_ValueSpecifiedCellSpecifiedTable\ValueSpecifiedCellSpecifiedTable\Program.cs:line 85
at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
InnerException:
我试图用Decimal.Parse（）替换int.Parse（），但它告诉我：
"Error 1 Cannot implicitly convert type 'decimal' to 'int'. An explicit conversion exists (are you missing a cast?) C:\Users\hptSetupAdmin\Documents\Visual Studio 2012\Projects\_ValueSpecifiedCellSpecifiedTable\ValueSpecifiedCellSpecifiedTable \Program.cs 92 17 ValueSpecifiedCellSpecifiedTable
将int.Parse()更改为Decimal.Parse()我看不到哪里有要转换的int 。
请帮助我使用此代码来实现我的目标。
这是html文件供参考：
<html>
<head>
<title>Tables</title>
</head>
<body>
<table border="1">
<tr>
<th>Environment</th>
<th>Databases</th>
<th>Sites</th>
<th>Site Collection Storage Used (GB)</th>
<th>Ref</th>
</th>
</tr>
<tr>
<td>Public</td>
<td>14</td>
<td>28</td>
<td>32.6602</td>
<td>2</td>
</tr>
<tr>
<td>Local</td>
<td>5</td>
<td>8</td>
<td>7.0302</td>
<td>3</td>
</tr>
<tr>
<td>Shared</td>
<td>6</td>
<td>9</td>
<td>17.092</td>
<td>9</td>
</tr>
</table>
一般承认的答案
转换几乎肯定在LINQ语句之外：如果sum是一个int，那就是需要显式转换的地方。将sum声明为十进制或插入显式转换将解决问题：
// Site Collection Storage Used (GB)
sum = (int)doc.DocumentNode.SelectSingleNode("//table")
// The sum will be of the row elements
.Elements("tr")
// Skip this many rows from the top
.Skip(1)
// .ElementAt(2) = third column
// .Last() = last column
.Sum(tr => decimal.Parse(tr.Elements("td").ElementAt(3).InnerText));
Console.WriteLine("Site Collection Storage Used (GB): " + sum);
这是一个关于ideone的快速演示的链接（不可能在ideone上使用HTML敏捷包，所以我将你的数据复制到一个字符串数组中）。
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