Queryable.SkipWhile Queryable.SkipWhile Queryable.SkipWhile Queryable.SkipWhile Method

定義

只要指定的條件為 true,便略過序列中的項目,然後傳回其餘項目。Bypasses elements in a sequence as long as a specified condition is true and then returns the remaining elements.

多載

SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>)

只要指定的條件為 true,便略過序列中的項目,然後傳回其餘項目。Bypasses elements in a sequence as long as a specified condition is true and then returns the remaining elements.

SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Int32,Boolean>>) SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Int32,Boolean>>) SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Int32,Boolean>>) SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Int32,Boolean>>)

只要指定的條件為 true,便略過序列中的項目,然後傳回其餘項目。Bypasses elements in a sequence as long as a specified condition is true and then returns the remaining elements. 項目的索引是用於述詞功能的邏輯中。The element's index is used in the logic of the predicate function.

SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>)

只要指定的條件為 true,便略過序列中的項目,然後傳回其餘項目。Bypasses elements in a sequence as long as a specified condition is true and then returns the remaining elements.

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

類型參數

TSource

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

參數

source
IQueryable<TSource>

傳回項目的 IQueryable<T>An IQueryable<T> to return elements from.

predicate
Expression<Func<TSource,Boolean>>

用來測試每個項目是否符合條件的函式。A function to test each element for a condition.

傳回

IQueryable<TSource>

IQueryable<T>,其中包含的項目位於 source,而且是從沒有通過 predicate 所指定之測試的線性系列中第一個項目開始。An IQueryable<T> that contains elements from source starting at the first element in the linear series that does not pass the test specified by predicate.

例外狀況

sourcepredicatenullsource or predicate is null.

範例

下列程式碼範例示範當條件為SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) true 時, 如何使用略過陣列的元素。The following code example demonstrates how to use SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) to skip elements of an array as long as a condition is true.

int[] grades = { 59, 82, 70, 56, 92, 98, 85 };

// Get all grades less than 80 by first
// sorting the grades in descending order and then
// taking all the grades after the first grade
// that is less than 80.
IEnumerable<int> lowerGrades =
    grades.AsQueryable()
    .OrderByDescending(grade => grade)
    .SkipWhile(grade => grade >= 80);

Console.WriteLine("All grades below 80:");
foreach (int grade in lowerGrades)
    Console.WriteLine(grade);

/*
    This code produces the following output:

    All grades below 80:
    70
    59
    56
*/

Dim grades() As Integer = {59, 82, 70, 56, 92, 98, 85}

' Get all grades less than 80 by first  sorting the grades 
' in descending order and then taking all the grades that 
' occur after the first grade that is less than 80.
Dim lowerGrades = grades.AsQueryable() _
    .OrderByDescending(Function(grade) grade) _
    .SkipWhile(Function(grade) grade >= 80)

Dim output As New System.Text.StringBuilder
output.AppendLine("All grades below 80:")
For Each grade As Integer In lowerGrades
    output.AppendLine(grade)
Next

' Display the output.
MsgBox(output.ToString())

' This code produces the following output:

' All grades below 80:
' 70
' 59
' 56

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SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>)結構化泛型方法的方式呼叫本身。 MethodCallExpression SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>)The SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) method generates a MethodCallExpression that represents calling SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) itself as a constructed generic method. 然後, 它會MethodCallExpression將傳遞CreateQuery(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 CreateQuery(Expression) method of the IQueryProvider represented by the Provider property of the source parameter.

因執行代表呼叫SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>)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 SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) depends on the implementation of the type of the source parameter. 預期的行為是將它套用predicate至中source的每個專案, 直到predicate找到傳回 false 的元素為止。The expected behavior is that it applies predicate to each element in source until it finds an element for which predicate returns false. 會傳回該專案和所有剩餘的元素。That element and all the remaining elements are returned.

SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Int32,Boolean>>) SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Int32,Boolean>>) SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Int32,Boolean>>) SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Int32,Boolean>>)

只要指定的條件為 true,便略過序列中的項目,然後傳回其餘項目。Bypasses elements in a sequence as long as a specified condition is true and then returns the remaining elements. 項目的索引是用於述詞功能的邏輯中。The element's index is used in the logic of the predicate function.

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static System::Linq::IQueryable<TSource> ^ SkipWhile(System::Linq::IQueryable<TSource> ^ source, System::Linq::Expressions::Expression<Func<TSource, int, bool> ^> ^ predicate);
public static System.Linq.IQueryable<TSource> SkipWhile<TSource> (this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<Func<TSource,int,bool>> predicate);
static member SkipWhile : System.Linq.IQueryable<'Source> * System.Linq.Expressions.Expression<Func<'Source, int, bool>> -> System.Linq.IQueryable<'Source>
<Extension()>
Public Function SkipWhile(Of TSource) (source As IQueryable(Of TSource), predicate As Expression(Of Func(Of TSource, Integer, Boolean))) As IQueryable(Of TSource)

類型參數

TSource

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

參數

source
IQueryable<TSource>

傳回項目的 IQueryable<T>An IQueryable<T> to return elements from.

predicate
Expression<Func<TSource,Int32,Boolean>>

用來測試各項目是否符合條件的函式;此函式的第二個參數代表來源項目的索引。A function to test each element for a condition; the second parameter of this function represents the index of the source element.

傳回

IQueryable<TSource>

IQueryable<T>,其中包含的項目位於 source,而且是從沒有通過 predicate 所指定之測試的線性系列中第一個項目開始。An IQueryable<T> that contains elements from source starting at the first element in the linear series that does not pass the test specified by predicate.

例外狀況

sourcepredicatenullsource or predicate is null.

範例

下列程式碼範例將示範如何使用SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Int32,Boolean>>)來略過陣列的元素, 前提是相依于元素索引的條件為 true。The following code example demonstrates how to use SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Int32,Boolean>>) to skip elements of an array as long as a condition that depends on the element's index is true.

int[] amounts = { 5000, 2500, 9000, 8000, 
                    6500, 4000, 1500, 5500 };

// Skip over amounts in the array until the first amount
// that is less than or equal to the product of its
// index in the array and 1000. Take the remaining items.
IEnumerable<int> query =
    amounts.AsQueryable()
    .SkipWhile((amount, index) => amount > index * 1000);

foreach (int amount in query)
    Console.WriteLine(amount);

/*
    This code produces the following output:

    4000
    1500
    5500
*/

Dim amounts() As Integer = {5000, 2500, 9000, 8000, _
                    6500, 4000, 1500, 5500}

' Skip over amounts in the array until the first amount
' that is less than or equal to the product of its
' index in the array and 1000. Take the remaining items.
Dim query = amounts.AsQueryable() _
    .SkipWhile(Function(amount, index) amount > index * 1000)

Dim output As New System.Text.StringBuilder
For Each amount As Integer In query
    output.AppendLine(amount)
Next

' Display the output.
MsgBox(output.ToString())

' This code produces the following output:

' 4000
' 1500
' 5500

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SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Int32,Boolean>>)結構化泛型方法的方式呼叫本身。 MethodCallExpression SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Int32,Boolean>>)The SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Int32,Boolean>>) method generates a MethodCallExpression that represents calling SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Int32,Boolean>>) itself as a constructed generic method. 然後, 它會MethodCallExpression將傳遞CreateQuery(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 CreateQuery(Expression) method of the IQueryProvider represented by the Provider property of the source parameter.

因執行代表呼叫SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Int32,Boolean>>)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 SkipWhile<TSource>(IQueryable<TSource>, Expression<Func<TSource,Int32,Boolean>>) depends on the implementation of the type of the source parameter. 預期的行為是將它套用predicate至中source的每個專案, 直到predicate找到傳回 false 的元素為止。The expected behavior is that it applies predicate to each element in source until it finds an element for which predicate returns false. 會傳回該專案和所有剩餘的元素。That element and all the remaining elements are returned. 每個來源元素的索引都會當做的第二個自predicate變數提供。The index of each source element is provided as the second argument to predicate.

適用於