我想从生成一对夫妇指定的参数的HTML表格。 具体而言，这两个参数我想传递到我的方法是：IEnumerable的名单，和T的性能。例如某个子集，让我们说我有这个类的一个列表：
class Person
{
string FirstName
string MiddleName
string LastName
}
比方说，在列表中有5人在里面。 我希望能够做这样的事情来获得该类的一个HTML表格（或其它任意类）：
List<Person> people;
...add people to list
string HTML = GetMyTable(people, "FirstName", "LastName");
我敢肯定有一个更好的方式来指定我想从生成的表的属性（或属性我想排除从表中，这将是更好，因为我通常会想大部分或所有类的属性），但我“不知道如何（我从来没有使用反射，但我猜这就是如何）。 此外，该方法应该接受任何类型的类的列表。
上的任何巧妙的构思如何做到这一点？
也许这样的事情？
var html = GetMyTable(people, x => x.LastName, x => x.FirstName);
public static string GetMyTable<T>(IEnumerable<T> list,params Func<T,object>[] fxns)
{
StringBuilder sb = new StringBuilder();
sb.Append("<TABLE>\n");
foreach (var item in list)
{
sb.Append("<TR>\n");
foreach(var fxn in fxns)
{
sb.Append("<TD>");
sb.Append(fxn(item));
sb.Append("</TD>");
}
sb.Append("</TR>\n");
}
sb.Append("</TABLE>");
return sb.ToString();
}
--version 2.0--
public static string GetMyTable<T>(IEnumerable<T> list, params Expression<Func<T, object>>[] fxns)
{
StringBuilder sb = new StringBuilder();
sb.Append("<TABLE>\n");
sb.Append("<TR>\n");
foreach (var fxn in fxns)
{
sb.Append("<TD>");
sb.Append(GetName(fxn));
sb.Append("</TD>");
}
sb.Append("</TR> <!-- HEADER -->\n");
foreach (var item in list)
{
sb.Append("<TR>\n");
foreach (var fxn in fxns)
{
sb.Append("<TD>");
sb.Append(fxn.Compile()(item));
sb.Append("</TD>");
}
sb.Append("</TR>\n");
}
sb.Append("</TABLE>");
return sb.ToString();
}
static string GetName<T>(Expression<Func<T, object>> expr)
{
var member = expr.Body as MemberExpression;
if (member != null)
return GetName2(member);
var unary = expr.Body as UnaryExpression;
if (unary != null)
return GetName2((MemberExpression)unary.Operand);
return "?+?";
}
static string GetName2(MemberExpression member)
{
var fieldInfo = member.Member as FieldInfo;
if (fieldInfo != null)
{
var d = fieldInfo.GetCustomAttribute(typeof(DescriptionAttribute)) as DescriptionAttribute;
if (d != null) return d.Description;
return fieldInfo.Name;
}
var propertInfo = member.Member as PropertyInfo;
if (propertInfo != null)
{
var d = propertInfo.GetCustomAttribute(typeof(DescriptionAttribute)) as DescriptionAttribute;
if (d != null) return d.Description;
return propertInfo.Name;
}
return "?-?";
}
PS：调用fxn.Compile()反复可以在一个紧密的循环性能杀手。 它可以更好地缓存它在字典中。
这是我做的，它似乎很好地工作，而不是一个巨大的性能损失。
public static string ToHtmlTable<T>(this List<T> listOfClassObjects)
{
var ret = string.Empty;
return listOfClassObjects == null || !listOfClassObjects.Any()
? ret
: "<table>" +
listOfClassObjects.First().GetType().GetProperties().Select(p => p.Name).ToList().ToColumnHeaders() +
listOfClassObjects.Aggregate(ret, (current, t) => current + t.ToHtmlTableRow()) +
"</table>";
}
public static string ToColumnHeaders<T>(this List<T> listOfProperties)
{
var ret = string.Empty;
return listOfProperties == null || !listOfProperties.Any()
? ret
: "<tr>" +
listOfProperties.Aggregate(ret,
(current, propValue) =>
current +
("<th style='font-size: 11pt; font-weight: bold; border: 1pt solid black'>" +
(Convert.ToString(propValue).Length <= 100
? Convert.ToString(propValue)
: Convert.ToString(propValue).Substring(0, 100)) + "..." + "</th>")) +
"</tr>";
}
public static string ToHtmlTableRow<T>(this T classObject)
{
var ret = string.Empty;
return classObject == null
? ret
: "<tr>" +
classObject.GetType()
.GetProperties()
.Aggregate(ret,
(current, prop) =>
current + ("<td style='font-size: 11pt; font-weight: normal; border: 1pt solid black'>" +
(Convert.ToString(prop.GetValue(classObject, null)).Length <= 100
? Convert.ToString(prop.GetValue(classObject, null))
: Convert.ToString(prop.GetValue(classObject, null)).Substring(0, 100) +
"...") +
"</td>")) + "</tr>";
}
要使用它只是传递ToHtmlTable（）一个列表示例：
文件清单= GetMyListOfDocuments（）; 变种表= documents.ToHtmlTable（）;
下面是使用反射两种方法，其一：
public static string GetMyTable(IEnumerable list, params string[] columns)
{
var sb = new StringBuilder();
foreach (var item in list)
{
//todo this should actually make an HTML table, not just get the properties requested
foreach (var column in columns)
sb.Append(item.GetType().GetProperty(column).GetValue(item, null));
}
return sb.ToString();
}
//used like
string HTML = GetMyTable(people, "FirstName", "LastName");
或使用lambda表达式：
public static string GetMyTable<T>(IEnumerable<T> list, params Func<T, object>[] columns)
{
var sb = new StringBuilder();
foreach (var item in list)
{
//todo this should actually make an HTML table, not just get the properties requested
foreach (var column in columns)
sb.Append(column(item));
}
return sb.ToString();
}
//used like
string HTML = GetMyTable(people, x => x.FirstName, x => x.LastName);
随着lambda表达式，发生了什么事是你传递方法的GetMyTable方法来获取每个属性。 这个拥有像强类型，也可能表现反射利益。
祝你好运
Extention方法
public static class EnumerableExtension
{
public static string ToHtmlTable<T>(this IEnumerable<T> list, List<string> headerList, List<CustomTableStyle> customTableStyles, params Func<T, object>[] columns)
{
if (customTableStyles == null)
customTableStyles = new List<CustomTableStyle>();
var tableCss = string.Join(" ", customTableStyles?.Where(w => w.CustomTableStylePosition == CustomTableStylePosition.Table).Where(w => w.ClassNameList != null).SelectMany(s => s.ClassNameList)) ?? "";
var trCss = string.Join(" ", customTableStyles?.Where(w => w.CustomTableStylePosition == CustomTableStylePosition.Tr).Where(w => w.ClassNameList != null).SelectMany(s => s.ClassNameList)) ?? "";
var thCss = string.Join(" ", customTableStyles?.Where(w => w.CustomTableStylePosition == CustomTableStylePosition.Th).Where(w => w.ClassNameList != null).SelectMany(s => s.ClassNameList)) ?? "";
var tdCss = string.Join(" ", customTableStyles?.Where(w => w.CustomTableStylePosition == CustomTableStylePosition.Td).Where(w => w.ClassNameList != null).SelectMany(s => s.ClassNameList)) ?? "";
var tableInlineCss = string.Join(";", customTableStyles?.Where(w => w.CustomTableStylePosition == CustomTableStylePosition.Table).Where(w => w.InlineStyleValueList != null).SelectMany(s => s.InlineStyleValueList?.Select(x => String.Format("{0}:{1}", x.Key, x.Value)))) ?? "";
var trInlineCss = string.Join(";", customTableStyles?.Where(w => w.CustomTableStylePosition == CustomTableStylePosition.Tr).Where(w => w.InlineStyleValueList != null).SelectMany(s => s.InlineStyleValueList?.Select(x => String.Format("{0}:{1}", x.Key, x.Value)))) ?? "";
var thInlineCss = string.Join(";", customTableStyles?.Where(w => w.CustomTableStylePosition == CustomTableStylePosition.Th).Where(w => w.InlineStyleValueList != null).SelectMany(s => s.InlineStyleValueList?.Select(x => String.Format("{0}:{1}", x.Key, x.Value)))) ?? "";
var tdInlineCss = string.Join(";", customTableStyles?.Where(w => w.CustomTableStylePosition == CustomTableStylePosition.Td).Where(w => w.InlineStyleValueList != null).SelectMany(s => s.InlineStyleValueList?.Select(x => String.Format("{0}:{1}", x.Key, x.Value)))) ?? "";
var sb = new StringBuilder();
sb.Append($"<table{(string.IsNullOrEmpty(tableCss) ? "" : $" class=\"{tableCss}\"")}{(string.IsNullOrEmpty(tableInlineCss) ? "" : $" style=\"{tableInlineCss}\"")}>");
if (headerList != null)
{
sb.Append($"<tr{(string.IsNullOrEmpty(trCss) ? "" : $" class=\"{trCss}\"")}{(string.IsNullOrEmpty(trInlineCss) ? "" : $" style=\"{trInlineCss}\"")}>");
foreach (var header in headerList)
{
sb.Append($"<th{(string.IsNullOrEmpty(thCss) ? "" : $" class=\"{thCss}\"")}{(string.IsNullOrEmpty(thInlineCss) ? "" : $" style=\"{thInlineCss}\"")}>{header}</th>");
}
sb.Append("</tr>");
}
foreach (var item in list)
{
sb.Append($"<tr{(string.IsNullOrEmpty(trCss) ? "" : $" class=\"{trCss}\"")}{(string.IsNullOrEmpty(trInlineCss) ? "" : $" style=\"{trInlineCss}\"")}>");
foreach (var column in columns)
sb.Append($"<td{(string.IsNullOrEmpty(tdCss) ? "" : $" class=\"{tdCss}\"")}{(string.IsNullOrEmpty(tdInlineCss) ? "" : $" style=\"{tdInlineCss}\"")}>{column(item)}</td>");
sb.Append("</tr>");
}
sb.Append("</table>");
return sb.ToString();
}
public class CustomTableStyle
{
public CustomTableStylePosition CustomTableStylePosition { get; set; }
public List<string> ClassNameList { get; set; }
public Dictionary<string, string> InlineStyleValueList { get; set; }
}
public enum CustomTableStylePosition
{
Table,
Tr,
Th,
Td
}
}
运用
private static void Main(string[] args)
{
var dataList = new List<TestDataClass>
{
new TestDataClass {Name = "A", Lastname = "B", Other = "ABO"},
new TestDataClass {Name = "C", Lastname = "D", Other = "CDO"},
new TestDataClass {Name = "E", Lastname = "F", Other = "EFO"},
new TestDataClass {Name = "G", Lastname = "H", Other = "GHO"}
};
var headerList = new List<string> { "Name", "Surname", "Merge" };
var customTableStyle = new List<EnumerableExtension.CustomTableStyle>
{
new EnumerableExtension.CustomTableStyle{CustomTableStylePosition = EnumerableExtension.CustomTableStylePosition.Table, InlineStyleValueList = new Dictionary<string, string>{{"font-family", "Comic Sans MS" },{"font-size","15px"}}},
new EnumerableExtension.CustomTableStyle{CustomTableStylePosition = EnumerableExtension.CustomTableStylePosition.Table, InlineStyleValueList = new Dictionary<string, string>{{"background-color", "yellow" }}},
new EnumerableExtension.CustomTableStyle{CustomTableStylePosition = EnumerableExtension.CustomTableStylePosition.Tr, InlineStyleValueList =new Dictionary<string, string>{{"color","Blue"},{"font-size","10px"}}},
new EnumerableExtension.CustomTableStyle{CustomTableStylePosition = EnumerableExtension.CustomTableStylePosition.Th,ClassNameList = new List<string>{"normal","underline"}},
new EnumerableExtension.CustomTableStyle{CustomTableStylePosition = EnumerableExtension.CustomTableStylePosition.Th,InlineStyleValueList =new Dictionary<string, string>{{ "background-color", "gray"}}},
new EnumerableExtension.CustomTableStyle{CustomTableStylePosition = EnumerableExtension.CustomTableStylePosition.Td, InlineStyleValueList =new Dictionary<string, string>{{"color","Red"},{"font-size","15px"}}},
};
var htmlResult = dataList.ToHtmlTable(headerList, customTableStyle, x => x.Name, x => x.Lastname, x => $"{x.Name} {x.Lastname}");
}
private class TestDataClass
{
public string Name { get; set; }
public string Lastname { get; set; }
public string Other { get; set; }
}
结果
<table class="normal underline" style="font-family:Comic Sans MS;font-size:15px;background-color:yellow">
<tr style="color:Blue;font-size:10px">
<th style="background-color:gray">Name</th>
<th style="background-color:gray">Surname</th>
<th style="background-color:gray">Merge</th>
</tr>
<tr style="color:Blue;font-size:10px">
<td style="color:Red;font-size:15px">A</td>
<td style="color:Red;font-size:15px">B</td>
<td style="color:Red;font-size:15px">A B</td>
</tr>
<tr style="color:Blue;font-size:10px">
<td style="color:Red;font-size:15px">C</td>
<td style="color:Red;font-size:15px">D</td>
<td style="color:Red;font-size:15px">C D</td>
</tr>
<tr style="color:Blue;font-size:10px">
<td style="color:Red;font-size:15px">E</td>
<td style="color:Red;font-size:15px">F</td>
<td style="color:Red;font-size:15px">E F</td>
</tr>
<tr style="color:Blue;font-size:10px">
<td style="color:Red;font-size:15px">G</td>
<td style="color:Red;font-size:15px">H</td>
<td style="color:Red;font-size:15px">G H</td
</tr>
