我有一个Library1.dll包含一些接口的程序集,它们被序列化为数据库中的字节数组.出于某些原因,我们必须更改接口属性和定义.所以现在我正在编写一个迁移实用程序.所以我有2个版本Library1.dll,在我的实用程序中,我创建了一个文件夹,我存储了新版本Library1.dll.这个实用程序反过来也引用Library1.dllbin文件夹包含Library1.dll但是这个dll是在旧版本上编译的.我的新版本Library1.dll存储在一个私有路径中,我传递给Assembly.ReflectionOnlyLoadFrom函数实例化,因此GetTypes在加载的程序集上进一步使我能够进行数据转换.
但是ReflectionTypeLoadException当我试图Library1.dll从私人路径加载时我总是得到.
请帮帮忙!!! 任何帮助,将不胜感激.我真的被卡住了.
谢谢,AG
因此,当我在我的F#代码中创建一些属性时,因为F#不支持自动属性,据我所知.我必须创建支持字段并将它们初始化为null,这在函数式编程术语中似乎不正确.例如
let mutable albums : DbSet = null
let mutable genres : DbSet = null
member x.Albums
with get() = albums
and set(value) = albums <- value
member x.Genres
with get() = genres
and set (value) = genres <- value
Run Code Online (Sandbox Code Playgroud)
这样做有更好的方法吗？非常感谢你的建议.
如何从Seq构造字典.我似乎无法正确使用语法.
所以我有一个Seq,我想从它构建一个字典,类似于
文献
<Overrides>
<token key="A" value="1"/>
<token key="B" value="2"/>
<token key="C" value="3"/>
<token key="D" value="4"/>
<token key="E" value="5"/>
<token key="F" value="6"/>
let elem = docs |> Seq.map(fun x -> x.Descendants(XName.op_Implicit "Overrides").Elements(XName.op_Implicit "token"))
|> Seq.head
|> Seq.iter(fun (k: XElement , v:XElement) -> k.Attribute(XName.op_Implicit "key").Value, v.Attribute("value").Value)
但得到运行时错误
错误1此表达式应具有类型XElement,但此处的类型为"a*"b
我最近一直在玩F#.我想知道而不是使用for循环来生成一个元素序列,它与列表中的每个其他元素相乘,我如何使用Seq map函数或类似的东西来生成类似下面的内容.
所以对于例如我有一个列表[1..10]我想应用一个产生类似结果的乐趣
[(1*1); (1*2);(1*3); (1*4); (1*5)......(2*1);(2*2);(2*3).....(3*1);(3*2)...]
我怎样才能做到这一点？
非常感谢你的帮助.
我之前有点问过这个问题,很抱歉再次提出类似的问题.但不幸的是,我无法真正理解如何设计一个受歧视的工会.
所以我有一堆看起来像的数据结构
type Artist( artistId : int, name : String ) =
do
if name = null then nullArg String.Empty
new(artistId: int) = Artist(artistId)
member x.ArtistId = artistId
member x.Name = name
and Genre() =
let mutable name = String.Empty
let mutable genreId : int = 0
let mutable description = String.Empty
let mutable albums = List.empty
member x.Description
with get() = description and set( value ) = description <- value
member x.Albums
with get() = albums and set ( …
Run Code Online (Sandbox Code Playgroud) 我无法让我的绑定工作在Detail ListView上.我已粘贴下面的所有MVVM模式代码.请帮忙!!!
我的观点:DirectoryDetailView.cs
<UserControl x:Class="S2.Views.DirectoryDetailView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<ListView Grid.Column="0" ItemsSource="{Binding Path = DirectoryDetails}"
IsSynchronizedWithCurrentItem="True"
SelectedItem="{Binding SelectedDirName, Mode=TwoWay}">
<ListView.View>
<GridView>
<GridViewColumn DisplayMemberBinding="{Binding Path = FileName}"
Header="File Name"/>
</GridView>
</ListView.View>
</ListView>
<ListView Grid.Column="1" Margin="10,0,0,0" ItemsSource="{Binding Path = DirectoryDetails}">
<ListView.View>
<GridView>
<GridViewColumn DisplayMemberBinding="{Binding Path = FileDetails.Length}"
Header="Length"/>
<GridViewColumn DisplayMemberBinding="{Binding Path = FileDetails.LastAccessTime}"
Header="LastAccessTime"/>
</GridView>
</ListView.View>
</ListView>
</Grid>
我的型号:
public class DirectoryModel : INotifyPropertyChanged
{
private string _fileName;
private DateTime _createdTime;
public string FileName
{
get
{
return _fileName; …我想知道如果我将常见的where子句查询提取到一个公共表达式中它会使我的查询更快,如果我在一个集合上说10个linq查询的东西与where子句的完全相同的第一部分.
我做了一个小例子来解释一下.
public class Person
{
public string First { get; set; }
public string Last { get; set; }
public int Age { get; set; }
public String Born { get; set; }
public string Living { get; set; }
}
public sealed class PersonDetails : List<Person>
{
}
PersonDetails d = new PersonDetails();
d.Add(new Person() {Age = 29, Born = "Timbuk Tu", First = "Joe", Last = "Bloggs", Living = "London"});
d.Add(new Person() { Age = 29, Born …我正在构建一个示例应用程序,其中我的类型层次结构不适用于Visual Studio中的类型排序.无论我以何种方式安排文件(向上,向下),我都无法定义所有类.
所以他们在f#项目中的顺序
type Artist() =
let mutable artistId = 0
let mutable name = String.Empty
member x.ArtistId
with get() = artistId
and set (value) = artistId <- value
member x.Name
with get() = name
and set ( value ) = name <- value
type Genre() =
let mutable name = String.Empty
let mutable genreId = 0
let mutable description = String.Empty
let mutable albums = [new Album()]
member x.Name
with get() = name
and set (value) = name <- …private void DoSomeWork()
{
ManualResetEvent[] waitEvents = new ManualResetEvent[rowCount];
int i = 0;
foreach (DataRow row in StoredProcedureParameters.Tables[0].Rows)
{
waitEvents[i] = new ManualResetEvent(false);
var workerClass = new WorkerClass();
var collection = new Dictionary<string, object>();
foreach (DataColumn dataColumn in StoredProcedureParameters.Tables[0].Columns)
{
collection[dataColumn.ColumnName] = row[dataColumn.ColumnName];
}
workerClass.Parameters = collection;
workerClass.Event = waitEvents[i];
i++;
ThreadPool.QueueUserWorkItem(WorkerFunction, workerClass);
}
}
private class WorkerClass
{
public ManualResetEvent Event;
public Dictionary<string, object> Parameters;
}
Hello Functional C#Friends,
所以这次我试图压缩我的代码并编写更多功能,lambda样式,以及我想创建不必要的列表和类,让编译器为我做的工作.我确实设法以功能方式转换了一小段代码,但之后我不知道如何去做.
var errorList = new List<DataRow>();
IEnumerable<DataRow> resultRows = GetResultRows();
resultRows
.Filter(row => row.Field<string>("status").Equals("FAILURE", StringComparison.InvariantCultureIgnoreCase))
.ForEach(row => { errorList.Add(row); });
if (errorList.Count > 0)
{
var excludedBooks = new List<string>();
foreach (DataRow row in errorList)
{
if (ToUseBooksList.Contains((string)row["main_book"]))
{
BookCheckResults.AddRow(string.Format("Error for MainBook {0}, RiskType {1}",
row["main_book"], row["risk_type"]));
if (!excludedBooks.Contains((string)row["main_book"]))
{
excludedBooks.Add((string)row["main_book"]);
}
}
}
}
我的扩展方法:
public static void ForEach<T>(this IEnumerable<T> collection, Action<T> action)
{
if (collection == null)
throw new ArgumentNullException("collection");
if (action == null)
throw …我真的很难理解为什么,当我改变我的代码使用lamdba表达式时,它不起作用.
此代码在控制台上工作和打印:
object dummy = new object();
InterServer.ExecuteDataReader(new InterServerRequest(ServerID.a_01, "dbo.getbooks")
{
Params = new Dictionary<string, object> {
{ "Tool", "d1" },
{ "Loc", locale == string.Empty ? null : locale } }
},
(_, reader) =>
{
reader.AsEnumerable(r => (r.GetString(r.GetOrdinal("book")))).ToList().ForEach(Console.WriteLine);
return new Response(dummy);
}
);
此代码已更改为使用lambda表达式; 它没有打印任何东西,我不明白为什么:
InterServer.ExecuteDataReader(new InterServerRequest(ServerID.a_01, "dbo.getbooks")
{
Params = new Dictionary<string, object> {
{ "Tool", "d1" },
{ "Loc", locale == string.Empty ? null : locale } }
},
(_, reader) =>
{
return new Response(new …我在应用程序中传递了大量数据作为byte []对象.在很多情况下,这也是存储问题.如果我在类中包装byte []怎么样呢？
[Serializable] public class MyClass {public byte [] Data {get; 组; }}
你们是否认为我会获得任何性能becoz现在引用类型将传递而不是值类型,因此数据不必每次都被复制.
期待您的回答
所以我有一个带有属性名称的类型类型.
我正在创建一个类型名称列表,如下所示.
let genres = new Genre()
[ genres.Name <- "Disco";
genres.Name <- "Jazz";
genres.Name <- "Rock"; ] |>ignore
想知道是否有更多的创造这种创造的方式？