blocks|key|1082280|text|查看反射，但基本是这样做的|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1082281|obj.GetType().GetProperties(..Instance+%7C+..Public)，您将获得一个定义的属性列表。检查属性的值类型，并将其与typeof(DateTime)进行比较。|1082282|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

look up reflection but basicly you do this

obj.GetType().GetProperties(..Instance | ..Public) and you got a list of the properties defined.. check the value type of the property and compare it to typeof(DateTime).

blocks|key|1297399|text|这叫做反射。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1297400|var+t+=+this;
var+props+=+t.GetType().GetProperties();
foreach+(var+prop+in+props)
{
++++if+(prop.PropertyType+==+typeof(DateTime))
++++{
++++++++//do+stuff+like+prop.SetValue(t,+DateTime.Now,+null);

++++}
}|code-block|syntax|javascript|1297401|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

It's called Reflection. 

<pre><code>var t = this;
var props = t.GetType().GetProperties();
foreach (var prop in props)
{
 if (prop.PropertyType == typeof(DateTime))
 {
 //do stuff like prop.SetValue(t, DateTime.Now, null);

 }
}
</code></pre>

blocks|key|1082323|text|class+HasDateTimes
{
++public+DateTime+Foo+{+get;+set;+}
++public+string+NotWanted+{+get;+set;+}
++public+DateTime+Bar+{+get+{+return+DateTime.MinValue;+}+}
}

static+void+Main(string[]+args)
{
++foreach+(var+propertyInfo+in+
++++from+p+in+typeof(HasDateTimes).GetProperties()
++++++where+Equals(p.PropertyType,+typeof(DateTime))+select+p)
++{
++++Console.WriteLine(propertyInfo.Name);
++}
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1082324|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>class HasDateTimes
{
 public DateTime Foo { get; set; }
 public string NotWanted { get; set; }
 public DateTime Bar { get { return DateTime.MinValue; } }
}

static void Main(string[] args)
{
 foreach (var propertyInfo in 
 from p in typeof(HasDateTimes).GetProperties()
 where Equals(p.PropertyType, typeof(DateTime)) select p)
 {
 Console.WriteLine(propertyInfo.Name);
 }
}
</code></pre>

blocks|key|1297557|text|您可以使用reflection来实现这一点。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1297558|您的场景可能如下所示：|1297559|++++static+void+Main(string[]+args)
++++{
++++++++var+list+=+new+List<Mammal>();

++++++++list.Add(new+Person+{+Name+=+"Filip",+DOB+=+DateTime.Now+});
++++++++list.Add(new+Person+{+Name+=+"Peter",+DOB+=+DateTime.Now+});
++++++++list.Add(new+Person+{+Name+=+"Goran",+DOB+=+DateTime.Now+});
++++++++list.Add(new+Person+{+Name+=+"Markus",+DOB+=+DateTime.Now+});

++++++++list.Add(new+Dog+{+Name+=+"Sparky",+Breed+=+"Unknown"+});
++++++++list.Add(new+Dog+{+Name+=+"Little+Kid",+Breed+=+"Unknown"+});
++++++++list.Add(new+Dog+{+Name+=+"Zorro",+Breed+=+"Unknown"+});

++++++++foreach+(var+item+in+list)
++++++++++++Console.WriteLine(item.Speek());

++++++++list+=+ReCalculateDOB(list);

++++++++foreach+(var+item+in+list)
++++++++++++Console.WriteLine(item.Speek());
++++}|code-block|syntax|javascript|1297560|你想重新计算所有哺乳动物的生日。上面的实现如下所示：|1297561|internal+interface+Mammal
{
++++string+Speek();
}

internal+class+Person+:+Mammal
{
++++public+string+Name+{+get;+set;+}
++++public+DateTime+DOB+{+get;+set;+}

++++public+string+Speek()
++++{
++++++++return+"My+DOB+is:+"+%2B+DOB.ToString()+;
++++}
}
internal+class+Dog+:+Mammal
{
++++public+string+Name+{+get;+set;+}
++++public+string+Breed+{+get;+set;+}

++++public+string+Speek()
++++{
++++++++return+"Woff!";
++++}
}|1297562|因此，基本上你需要做的是使用Relfection，这是一种在运行时检查类型并获取类型属性和其他类似内容的机制。下面是一个例子，告诉你如何为每只得到一只道布的哺乳动物在上面的时间基础上增加10天。|1297563|static+List<Mammal>+ReCalculateDOB(List<Mammal>+list)
{
++++foreach+(var+item+in+list)
++++{
++++++++var+properties+=+item.GetType().GetProperties();
++++++++foreach+(var+property+in+properties)
++++++++{
++++++++++++if+(property.PropertyType+==+typeof(DateTime))
++++++++++++++++property.SetValue(item,+((DateTime)property.GetValue(item,+null)).AddDays(10),+null);
++++++++}
++++}

++++return+list;
}|1297564|只需记住，使用反射可能会很慢，而且通常是很慢的。|1297565|但是，上面的代码将打印以下内容：|1297566|My+DOB+is:+2010-03-22+09:18:12
My+DOB+is:+2010-03-22+09:18:12
My+DOB+is:+2010-03-22+09:18:12
My+DOB+is:+2010-03-22+09:18:12
Woff!
Woff!
Woff!
My+DOB+is:+2010-04-01+09:18:12
My+DOB+is:+2010-04-01+09:18:12
My+DOB+is:+2010-04-01+09:18:12
My+DOB+is:+2010-04-01+09:18:12
Woff!
Woff!
Woff!|1297567|entityMap|0|LINK|mutability|MUTABLE|url|http://msdn.microsoft.com/en-us/library/ms173183(VS.80).aspx^0|5|A|0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|16|8|@]|9|@$A|17|B|18|1|19]]|C|$]]|$1|D|3|E|5|6|7|1A|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|1B|8|@]|9|@]|C|$I|J]]|$1|K|3|L|5|6|7|1C|8|@]|9|@]|C|$]]|$1|M|3|N|5|H|7|1D|8|@]|9|@]|C|$I|J]]|$1|O|3|P|5|6|7|1E|8|@]|9|@]|C|$]]|$1|Q|3|R|5|H|7|1F|8|@]|9|@]|C|$I|J]]|$1|S|3|T|5|6|7|1G|8|@]|9|@]|C|$]]|$1|U|3|V|5|6|7|1H|8|@]|9|@]|C|$]]|$1|W|3|X|5|H|7|1I|8|@]|9|@]|C|$I|J]]|$1|Y|3|-4|5|6|7|1J|8|@]|9|@]|C|$]]]|Z|$10|$5|11|12|13|C|$14|15]]]]

You can use <a href="http://msdn.microsoft.com/en-us/library/ms173183(VS.80).aspx" rel="noreferrer">reflection</a> for this.

Your scenario might look somewhat like this:

<pre><code> static void Main(string[] args)
 {
 var list = new List&lt;Mammal&gt;();

 list.Add(new Person { Name = "Filip", DOB = DateTime.Now });
 list.Add(new Person { Name = "Peter", DOB = DateTime.Now });
 list.Add(new Person { Name = "Goran", DOB = DateTime.Now });
 list.Add(new Person { Name = "Markus", DOB = DateTime.Now });

 list.Add(new Dog { Name = "Sparky", Breed = "Unknown" });
 list.Add(new Dog { Name = "Little Kid", Breed = "Unknown" });
 list.Add(new Dog { Name = "Zorro", Breed = "Unknown" });

 foreach (var item in list)
 Console.WriteLine(item.Speek());

 list = ReCalculateDOB(list);

 foreach (var item in list)
 Console.WriteLine(item.Speek());
 }
</code></pre>

Where you want to re-calculate the Birthdays of all Mammals. And the Implementations of the above are looking like this:

<pre><code>internal interface Mammal
{
 string Speek();
}

internal class Person : Mammal
{
 public string Name { get; set; }
 public DateTime DOB { get; set; }

 public string Speek()
 {
 return "My DOB is: " + DOB.ToString() ;
 }
}
internal class Dog : Mammal
{
 public string Name { get; set; }
 public string Breed { get; set; }

 public string Speek()
 {
 return "Woff!";
 }
}
</code></pre>

So basicly what you need to do is to use Relfection, which is a mechanizm to check types and get the types properties and other things like that in run time. Here is an example on how you add 10 days to the above DOB's for each Mammal that got a DOB.

<pre><code>static List&lt;Mammal&gt; ReCalculateDOB(List&lt;Mammal&gt; list)
{
 foreach (var item in list)
 {
 var properties = item.GetType().GetProperties();
 foreach (var property in properties)
 {
 if (property.PropertyType == typeof(DateTime))
 property.SetValue(item, ((DateTime)property.GetValue(item, null)).AddDays(10), null);
 }
 }

 return list;
}
</code></pre>

Just remember that using reflection can be slow, and it is slow generally.

However, the Above will print this:

<pre><code>My DOB is: 2010-03-22 09:18:12
My DOB is: 2010-03-22 09:18:12
My DOB is: 2010-03-22 09:18:12
My DOB is: 2010-03-22 09:18:12
Woff!
Woff!
Woff!
My DOB is: 2010-04-01 09:18:12
My DOB is: 2010-04-01 09:18:12
My DOB is: 2010-04-01 09:18:12
My DOB is: 2010-04-01 09:18:12
Woff!
Woff!
Woff!
</code></pre>

blocks|key|1082542|text|对于这个问题，如果你有PowerShell+(Vista+/Windows7，Windows2008已经安装了)，你只需要启动控制台，对于DateTime，例如do|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1082543|Get-Date+%7C+Get-Member|code-block|syntax|javascript|1082544|它将列出DateTime实例的成员。您还可以查看静态成员：|1082545|Get-Date+%7C+Get-Member+-Static|1082546|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

For very quick answers and pointers to that question, and if you have PowerShell available (Vista / Windows 7, Windows 2008 already got it installed) you can just fire up the console and for DateTime e.g. do

<pre><code>Get-Date | Get-Member
</code></pre>

Which will list you the members of a DateTime instance. You can also look at the static members:

<pre><code>Get-Date | Get-Member -Static
</code></pre>

blocks|key|1082606|text|如果您关心反射对性能的影响，您可能会对Fasterflect感兴趣，这是一个使查询和访问成员更容易、更快的库。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1082607|对于instace，可以使用Fasterflect重写MaxGuernseyIII的代码，如下所示：|1082608|var+query+=+from+property+in+typeof(HasDateTimes).Properties()
++++++++++++where+property.Type()+==+typeof(DateTime)
++++++++++++select+p;
Array.ForEach(+query.ToArray(),+p+=>+Console.WriteLine(+p.Name+)+);|code-block|syntax|javascript|1082609|Fasterflect使用轻量级代码生成来加快访问速度(提高2-5倍，如果直接缓存和调用生成的委托，则速度接近本地速度)。查询成员通常更容易、更方便，但不会更快。请注意，这些数字不包括JIT编译生成的代码的重大初始开销，因此只有在重复访问时才能看到性能提升。|1082610|免责声明:我是该项目的贡献者。|1082611|entityMap|0|LINK|mutability|MUTABLE|url|http://fasterflect.codeplex.com/^0|J|B|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@$A|X|B|Y|1|Z]]|C|$]]|$1|D|3|E|5|6|7|10|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|11|8|@]|9|@]|C|$I|J]]|$1|K|3|L|5|6|7|12|8|@]|9|@]|C|$]]|$1|M|3|N|5|6|7|13|8|@]|9|@]|C|$]]|$1|O|3|-4|5|6|7|14|8|@]|9|@]|C|$]]]|P|$Q|$5|R|S|T|C|$U|V]]]]

If you are concerned about the performance impact of reflection you might be interested in <a href="http://fasterflect.codeplex.com" rel="nofollow noreferrer">Fasterflect</a>, a library to make querying and accessing members easier and faster.

For instace, MaxGuernseyIII's code might be rewritten using Fasterflect like this:

<pre><code>var query = from property in typeof(HasDateTimes).Properties()
 where property.Type() == typeof(DateTime)
 select p;
Array.ForEach( query.ToArray(), p =&gt; Console.WriteLine( p.Name ) );
</code></pre>

Fasterflect uses light-weight code generation to make accesses faster (by a factor of 2-5 times, or with near-native speeds if you cache and invoke the generated delegates directly). Querying for members is generally easier and more convenient but not any faster. Note that these numbers do not include the significant initial overhead of JIT-compiling the generated code, so performance gains only become visible for repeated accesses.

Disclaimer: I am a contributor to the project.

blocks|key|1297735|text|嘿，这个问题有点老了，但你可以用这个：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1297736|在类中(选择所有值)-设置值将在没有强制转换的情况下运行，它只是为了选择：|1297737|(from+property+in+this.GetType().GetProperties()
++++++++++++++++++++where+property.PropertyType+==+typeof(DateTime)
++++++++++++++++++++select+property.GetValue(this)).Cast<DateTime>()|code-block|syntax|javascript|1297738|在类的外部将是：|1297739|var+instance+=+new+MyClass();
var+times+=+(from+property+in+instance.GetType().GetProperties()
++++++++++++++++++++++++where+property.PropertyType+==+typeof(DateTime)
++++++++++++++++++++++++select+property.GetValue(instance)).Cast<DateTime>()|1297740|为了获得最大的日期时间值，我运行以下命令|1297741|var+lastChange+=+(from+property+in+this.GetType().GetProperties()
++++++++++++++++++++++++where+property.PropertyType+==+typeof(DateTime)
++++++++++++++++++++++++select+property.GetValue(this)).Cast<DateTime>().Max();|1297742|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|V|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|W|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|X|8|@]|9|@]|A|$]]|$1|O|3|P|5|F|7|Y|8|@]|9|@]|A|$G|H]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

Hey this question is a little bit older but you could use this:

within the class (selecting all values) - setting values would run without the cast it `s just for selecting:

<pre><code>(from property in this.GetType().GetProperties()
 where property.PropertyType == typeof(DateTime)
 select property.GetValue(this)).Cast&lt;DateTime&gt;()
</code></pre>

outside of the class would be:

<pre><code>var instance = new MyClass();
var times = (from property in instance.GetType().GetProperties()
 where property.PropertyType == typeof(DateTime)
 select property.GetValue(instance)).Cast&lt;DateTime&gt;()
</code></pre>

For getting the max Datetime value I run this

<pre><code>var lastChange = (from property in this.GetType().GetProperties()
 where property.PropertyType == typeof(DateTime)
 select property.GetValue(this)).Cast&lt;DateTime&gt;().Max();
</code></pre>

I need to adjust the datetime of a bunch of objects.

I'd like to loop through the properties of the class and if the type is dateTime adjust accordingly.

Is there any kind of 'describe type' built in goodness I can use?

How do I find all properties of type DateTime in an class?

我需要调整一堆对象的日期时间。我想遍历类的属性，如果类型为dateTime，则相应地进行调整。有没有什么“描述类型”是我可以使用的？

问如何在一个类中找到DateTime类型的所有属性？
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问如何在一个类中找到DateTime类型的所有属性？
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