小编Sli*_*ipe的帖子

我希望能够为多种扩展类型指定单选类型.

例如,说我们有海,在海里有很多种鱼.所以在XML中我会写:

<Sea name="Atlantic Ocean">
 <Tuna name="tuna1" />
 <Carp name="carp1" />
 <Carp name="carp2" />
 <Tuna name="tuna2" />
 <Salmon name="salmon1" />
</Sea>

XSD

  <xs:complexType name="Fish">
  </xs:complexType>

  <xs:complexType name="Salmon">
    <xs:complexContent>
      <xs:extension base="Fish">
      </xs:extension>
    </xs:complexContent>
  </xs:complexType>

  <xs:complexType name="Carp">
    <xs:complexContent>
      <xs:extension base="Fish">
      </xs:extension>
    </xs:complexContent>
  </xs:complexType>

  <xs:complexType name="Tuna">
    <xs:complexContent>
      <xs:extension base="Fish">
      </xs:extension>
    </xs:complexContent>
  </xs:complexType>

  <xs:complexType name="Sea">
    <xs:complexContent>
      <xs:extension base="GeoZone">
        <xs:sequence minOccurs="0" maxOccurs="unbounded">
          <xs:choice>
            <xs:element type="Fish" name="Fish" minOccurs="0" 
                        maxOccurs="unbounded"/>
          </xs:choice>
        </xs:sequence>
        <xs:attribute name="Name" type="xs:string" use="optional" />
      </xs:extension>
    </xs:complexContent>
  </xs:complexType>

不幸的是,这是无效的,因为我只能添加类型Fish本身而不是其扩展类型.

我正在尝试将子控件中的元素属性绑定到父窗口中的元素属性,它不起作用..

这是我正在尝试做的事情:

这是不起作用的xaml:

CurrentDate="{Binding ElementName=TimeBar, Path=SelectionStart,RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Window}}" 

谢谢.

我正在尝试使用以下代码更改背景颜色:

  data.getItemMetadata = function (index)
  {
       if (index === 5)
       {
           return  {cssClasses: "Unverified"};
       }      
   }

只要索引是均匀的,它就可以完美运行.但是使用奇数索引它对背景颜色没有影响(它对字体样式有影响).我怀疑它与斑马效应有关？(我不知道如何禁用它)

谢谢.

据我了解（我可能是错的）Pix.LoadFromFile是获取 Pix 进行处理的唯一方法。还有其他方法吗，例如位图？

我看了很多建议,但在过去的两个小时内无法解决这个问题.

SET DATEFORMAT DMY

DECLARE @Source DATETIME = '01/01/2001'
DECLARE @Destenaition DATETIME = '01/01/2020'

SELECT ST.[Group],
       ST.Shop,
       SUM(ST.Purchased) AS Total,
       CHG.Charged
FROM   (SELECT Personals.Groups.[Name]      AS 'Group',
               Cards.vPurchases.PersonalID,
               Personals.Registry.[Name],
               SUM(Cards.vPurchases.Ammont) AS Purchased,
               Cards.vPurchases.ShopName    AS Shop
        FROM   Cards.vPurchases
               INNER JOIN Personals.Registry
                 ON Personals.Registry.Id = Cards.vPurchases.PersonalID
               INNER JOIN Personals.Groups
                 ON Personals.Registry.[Group] = Personals.Groups.Id
               INNER JOIN Personals.Groups
                 ON Personals.Groups.Id = CHG.GroupID
        WHERE  Cards.vPurchases.[TimeStamp] >= @Source
               AND Cards.vPurchases.[TimeStamp] <= @Destenaition
        GROUP  BY Cards.vPurchases.PersonalID,
                  Personals.Registry.[Name],
                  Personals.Groups.[Name],
                  Cards.vPurchases.ShopName) ST,
       (SELECT PG.Id                      AS GroupID,
               SUM(Cards.vCharges.Amount) AS Charged
        FROM …

我正在尝试在where子句中使用列的别名.例如:

SELECT col1 AS alias1, col2 + col3 as sums 
FROM my_table
WHERE sums > 10

但后来我收到一条错误消息:

列总和不在指定的表中.

无论如何我能做到吗？

我注意到当我在游标循环中声明一个表变量时，该变量会在游标生命周期内保持不变。我的问题是，是否有一种方法可以声明变量，使其生命周期仅在迭代中持续存在？这是一个示例：

DECLARE @SourceTable TABLE(Id INT IDENTITY(1,1),Remarks VARCHAR(10))
INSERT INTO @SourceTable VALUES ('First')
INSERT INTO @SourceTable VALUES ('Second')
INSERT INTO @SourceTable VALUES ('Third ')

/* declare variables */
DECLARE @variable INT

DECLARE my_cursor CURSOR FAST_FORWARD READ_ONLY FOR SELECT Id FROM @SourceTable

OPEN my_cursor

FETCH NEXT FROM my_cursor INTO @variable

WHILE @@FETCH_STATUS = 0
BEGIN
    --Dose not creates a new instance
    DECLARE @VarTable TABLE (Remarks VARCHAR(10))

    INSERT INTO @VarTable
    SELECT TOP 1 Remarks FROM @SourceTable
    WHERE Id = @variable


    --Works as intended …

type bytesLookup = Map<byte,int list>
type lookupList = bytesLookup list

let maps:bytesLookup = Map.empty

let printArg arg = printfn(Printf.TextWriterFormat<unit>(arg))

let array1 = [|byte(0x02);byte(0xB1);byte(0xA3);byte(0x02);byte(0x18);byte(0x2F)|]

let InitializeNew(maps:bytesLookup,element,index) =
    maps.Add(element,List.empty<int>)(*KeyNotFoundException*)
    maps.[element]

let MapArray (arr:byte[],maps:bytesLookup ) =
   for i in 0..arr.Length do
       match maps.TryFind(arr.[i]) with
        | Some(e) -> i::e
        | None -> InitializeNew(maps,arr.[i],i)

MapArray(array1,maps);

printArg( maps.Count.ToString())

例外

System.Collections.Generic.KeyNotFoundException:给定的键不在字典中.在Microsoft.FSharp.Collections.MapTreeModule.find [TValue,a](IComparer 1 comparer, TValue k, MapTree2 m),2.get_Item(TKey key) at FSI_0012.MapArray(Byte[] arr, FSharpMap位于Script1.fsx 中的Microsoft.FSharp.Collections.FSharpMap 2 maps):第16行,位于Script1中的.$ FSI_0012.main @(). fsx:第20行

在函数中,我正在尝试使用int列表初始化地图中的新元素.我还尝试将新的int值同时推送到列表中.

我究竟做错了什么？