Queryable.Min Queryable.Min Queryable.Min Queryable.Min Method

定義

多載

Min<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) Min<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) Min<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) Min<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>)

對泛型 IQueryable<T> 的每個項目叫用投影函式,並傳回最小的結果值。Invokes a projection function on each element of a generic IQueryable<T> and returns the minimum resulting value.

Min<TSource>(IQueryable<TSource>) Min<TSource>(IQueryable<TSource>) Min<TSource>(IQueryable<TSource>) Min<TSource>(IQueryable<TSource>)

傳回泛型 IQueryable<T> 的最小值。Returns the minimum value of a generic IQueryable<T>.

Min<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) Min<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) Min<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) Min<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>)

對泛型 IQueryable<T> 的每個項目叫用投影函式,並傳回最小的結果值。Invokes a projection function on each element of a generic IQueryable<T> and returns the minimum resulting value.

public:
generic <typename TSource, typename TResult>
[System::Runtime::CompilerServices::Extension]
 static TResult Min(System::Linq::IQueryable<TSource> ^ source, System::Linq::Expressions::Expression<Func<TSource, TResult> ^> ^ selector);
public static TResult Min<TSource,TResult> (this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<Func<TSource,TResult>> selector);
static member Min : System.Linq.IQueryable<'Source> * System.Linq.Expressions.Expression<Func<'Source, 'Result>> -> 'Result
<Extension()>
Public Function Min(Of TSource, TResult) (source As IQueryable(Of TSource), selector As Expression(Of Func(Of TSource, TResult))) As TResult

類型參數

TSource

source 項目的類型。The type of the elements of source.

TResult

selector 表示之函式所傳回值的型別。The type of the value returned by the function represented by selector.

參數

source
IQueryable<TSource>

要判斷最小值的值序列。A sequence of values to determine the minimum of.

selector
Expression<Func<TSource,TResult>>

要套用到每個項目的投影函式。A projection function to apply to each element.

傳回

TResult TResult TResult TResult

序列中的最小值。The minimum value in the sequence.

例外狀況

sourceselectornullsource or selector is null.

範例

下列程式碼範例示範如何使用Min<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>)判斷一系列預計值中的最小值。The following code example demonstrates how to use Min<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) to determine the minimum value in a sequence of projected values.

class Pet
{
    public string Name { get; set; }
    public int Age { get; set; }
}

public static void MinEx2()
{
    Pet[] pets = { new Pet { Name="Barley", Age=8 },
                   new Pet { Name="Boots", Age=4 },
                   new Pet { Name="Whiskers", Age=1 } };

    // Get the Pet object that has the smallest Age value.
    int min = pets.AsQueryable().Min(pet => pet.Age);

    Console.WriteLine("The youngest animal is age {0}.", min);
}

/*
    This code produces the following output:

    The youngest animal is age 1.  
*/

Structure Pet
    Public Name As String
    Public Age As Integer
End Structure

Shared Sub MinEx2()
    Dim pets() As Pet = {New Pet With {.Name = "Barley", .Age = 8}, _
                   New Pet With {.Name = "Boots", .Age = 4}, _
                   New Pet With {.Name = "Whiskers", .Age = 1}}

    ' Get the Pet object that has the smallest Age value.
    Dim min As Integer = pets.AsQueryable().Min(Function(pet) pet.Age)

    MsgBox(String.Format("The youngest animal is age {0}.", min))
End Sub

'This code produces the following output:

'The youngest animal is age 1.  

備註

這個方法至少有一個類型Expression<TDelegate>的參數, 其類型引數是其中一個Func<T,TResult>類型。This method has at least one parameter of type Expression<TDelegate> whose type argument is one of the Func<T,TResult> types. 針對這些參數, 您可以傳入 lambda 運算式, 它會編譯成Expression<TDelegate>For these parameters, you can pass in a lambda expression and it will be compiled to an Expression<TDelegate>.

方法會產生, 其代表以Min<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>)結構化泛型方法的方式呼叫本身。 MethodCallExpression Min<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>)The Min<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) method generates a MethodCallExpression that represents calling Min<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) itself as a constructed generic method. 然後, 它會MethodCallExpression將傳遞Execute<TResult>(Expression)至由Provider source參數IQueryProvider的屬性所表示之的方法。It then passes the MethodCallExpression to the Execute<TResult>(Expression) method of the IQueryProvider represented by the Provider property of the source parameter.

因執行代表呼叫Min<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>)之運算式樹狀架構而產生的查詢行為, 取決於source參數類型的實作為。The query behavior that occurs as a result of executing an expression tree that represents calling Min<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) depends on the implementation of the type of the source parameter. 預期的行為是它selector會在中的每個元素上叫用source , 並傳回最小值。The expected behavior is that it invokes selector on each element in source and returns the minimum value.

Min<TSource>(IQueryable<TSource>) Min<TSource>(IQueryable<TSource>) Min<TSource>(IQueryable<TSource>) Min<TSource>(IQueryable<TSource>)

傳回泛型 IQueryable<T> 的最小值。Returns the minimum value of a generic IQueryable<T>.

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static TSource Min(System::Linq::IQueryable<TSource> ^ source);
public static TSource Min<TSource> (this System.Linq.IQueryable<TSource> source);
static member Min : System.Linq.IQueryable<'Source> -> 'Source
<Extension()>
Public Function Min(Of TSource) (source As IQueryable(Of TSource)) As TSource

類型參數

TSource

source 項目的類型。The type of the elements of source.

參數

source
IQueryable<TSource>

要判斷最小值的值序列。A sequence of values to determine the minimum of.

傳回

TSource TSource TSource TSource

序列中的最小值。The minimum value in the sequence.

例外狀況

範例

下列程式碼範例示範如何使用Min<TSource>(IQueryable<TSource>)來判斷序列中的最小值。The following code example demonstrates how to use Min<TSource>(IQueryable<TSource>) to determine the minimum value in a sequence.

double[] doubles = { 1.5E+104, 9E+103, -2E+103 };

double min = doubles.AsQueryable().Min();

Console.WriteLine("The smallest number is {0}.", min);

/*
    This code produces the following output:

    The smallest number is -2E+103.
*/

Dim doubles() As Double = {1.5E+104, 9.0E+103, -2.0E+103}

Dim min As Double = doubles.AsQueryable().Min()

MsgBox(String.Format("The smallest number is {0}.", min))

'This code produces the following output:

'The smallest number is -2E+103.

備註

方法會產生, 其代表以Min<TSource>(IQueryable<TSource>)結構化泛型方法的方式呼叫本身。 MethodCallExpression Min<TSource>(IQueryable<TSource>)The Min<TSource>(IQueryable<TSource>) method generates a MethodCallExpression that represents calling Min<TSource>(IQueryable<TSource>) itself as a constructed generic method. 然後, 它會MethodCallExpression將傳遞Execute<TResult>(Expression)至由Provider source參數IQueryProvider的屬性所表示之的方法。It then passes the MethodCallExpression to the Execute<TResult>(Expression) method of the IQueryProvider represented by the Provider property of the source parameter.

因執行代表呼叫Min<TSource>(IQueryable<TSource>)之運算式樹狀架構而產生的查詢行為, 取決於source參數類型的實作為。The query behavior that occurs as a result of executing an expression tree that represents calling Min<TSource>(IQueryable<TSource>) depends on the implementation of the type of the source parameter. 預期的行為是它會傳回中source的最小值。The expected behavior is that it returns the minimum value in source.

適用於