Contract.ForAll 方法

定義

多載

ForAll(Int32, Int32, Predicate<Int32>)

判斷特定條件對於指定之範圍內的所有整數是否有效。Determines whether a particular condition is valid for all integers in a specified range.

ForAll<T>(IEnumerable<T>, Predicate<T>)

判斷集合內的所有項目是否都出現在函式中。Determines whether all the elements in a collection exist within a function.

ForAll(Int32, Int32, Predicate<Int32>)

判斷特定條件對於指定之範圍內的所有整數是否有效。Determines whether a particular condition is valid for all integers in a specified range.

public:
 static bool ForAll(int fromInclusive, int toExclusive, Predicate<int> ^ predicate);
public static bool ForAll (int fromInclusive, int toExclusive, Predicate<int> predicate);
static member ForAll : int * int * Predicate<int> -> bool
Public Shared Function ForAll (fromInclusive As Integer, toExclusive As Integer, predicate As Predicate(Of Integer)) As Boolean

參數

fromInclusive
Int32

要傳遞至 predicate 的第一個整數。The first integer to pass to predicate.

toExclusive
Int32

要傳遞至 predicate 的最後一個整數加一。One more than the last integer to pass to predicate.

predicate
Predicate<Int32>

要評估指定範圍中整數是否存在的函式。The function to evaluate for the existence of the integers in the specified range.

傳回

如果 predicate 為從 fromInclusive 開始到 toExclusive - 1 的所有整數傳回 true,則為 truetrue if predicate returns true for all integers starting from fromInclusive to toExclusive - 1.

例外狀況

predicatenullpredicate is null.

toExclusive 小於 fromInclusivetoExclusive is less than fromInclusive.

範例

下列範例示範如何使用 ForAll 方法來判斷陣列是否有 null 元素。The following example demonstrates how to use the ForAll method to determine whether an array has a null element.

using System;
using System.Diagnostics.Contracts;
using System.Collections.Generic;
namespace AssumeEx
{
    class Program
    {
        // Start application with at least two arguments
        static void Main(string[] args)
        {
            args[1] = null;
            Contract.Requires(args != null && Contract.ForAll(0, args.Length, i => args[i] != null));
            // test the ForAll method.  This is only for purpose of demonstrating how ForAll works.
            CheckIndexes(args);
            Stack<string> numbers = new Stack<string>();
            numbers.Push("one");
            numbers.Push("two");
            numbers.Push(null);
            numbers.Push("four");
            numbers.Push("five");
            Contract.Requires(numbers != null && !Contract.ForAll(numbers, (String x) => x != null));
            // test the ForAll generic overload.  This is only for purpose of demonstrating how ForAll works.
            CheckTypeArray(numbers);
        }

        private static bool CheckIndexes(string[] args)
        {
            try
            {
                if (args != null && !Contract.ForAll(0, args.Length, i => args[i] != null))
                    throw new ArgumentException("The parameter array has a null element", "args");
                return true;
            }
            catch (ArgumentException e)
            {
                Console.WriteLine(e.Message);
                return false;
            }
        }
        private static bool CheckTypeArray(IEnumerable<String> xs)
        {
            try
            {
                if (xs != null && !Contract.ForAll(xs, (String x) => x != null))
                    throw new ArgumentException("The parameter array has a null element", "indexes");
                return true;
            }
            catch (ArgumentException e)
            {
                Console.WriteLine(e.Message);
                return false;
            }
        }
    }
}
Imports System.Diagnostics.Contracts
Imports System.Collections.Generic


Class Program

    ' Start application with at least two arguments.
    Shared Sub Main(ByVal args() As String)
        args(1) = Nothing
        Contract.Requires(Not (args Is Nothing) AndAlso Contract.ForAll(args, Function(s) s Is Nothing))
        ' test the ForAll method.  This is only for purpose of demonstrating how ForAll works.
        CheckIndexes(args)
        Dim numbers As New Stack(Of String)
        numbers.Push("one")
        numbers.Push("two")
        numbers.Push("three")
        numbers.Push("four")
        numbers.Push("five")

        Contract.Requires(Not (numbers Is Nothing) AndAlso Not Contract.ForAll(numbers, Function(s) s Is Nothing))
        ' test the ForAll generic overload. This is only for purpose of demonstrating how ForAll works.
        CheckTypeArray(numbers)

    End Sub


    Private Shared Function CheckIndexes(ByVal args() As String) As Boolean
        Try
            If Not (args Is Nothing) AndAlso Not Contract.ForAll(0, args.Length, Function(i) args(i) Is Nothing) Then
                Throw New ArgumentException("The parameter array has a null element", "args")
            End If
            Return True
        Catch e As ArgumentException
            Console.WriteLine(e.Message)
            Return False
        End Try

    End Function 'CheckIndexes

    Private Shared Function CheckTypeArray(ByVal xs As Stack(Of String)) As Boolean

        Try
            If Not (xs Is Nothing) AndAlso Not Contract.ForAll(xs, Function(s) s Is Nothing) Then

                Throw New ArgumentException("The parameter array has a null element", "Stack")
            End If
            Return True

        Catch e As ArgumentException
            Console.WriteLine(e.Message)
            Return False
        End Try

    End Function 'CheckTypeArray
End Class

備註

toExclusive 參數比最後一個整數還要新,以方便使用從0開始的整數範圍長度。The toExclusive parameter is one more than the last integer to facilitate using the length of a range of integers starting at 0. 例如,整數0到4的會設定為5。For example, it would be set to 5 for integers 0 through 4.

另請參閱

ForAll<T>(IEnumerable<T>, Predicate<T>)

判斷集合內的所有項目是否都出現在函式中。Determines whether all the elements in a collection exist within a function.

public:
generic <typename T>
 static bool ForAll(System::Collections::Generic::IEnumerable<T> ^ collection, Predicate<T> ^ predicate);
public static bool ForAll<T> (System.Collections.Generic.IEnumerable<T> collection, Predicate<T> predicate);
static member ForAll : seq<'T> * Predicate<'T> -> bool
Public Shared Function ForAll(Of T) (collection As IEnumerable(Of T), predicate As Predicate(Of T)) As Boolean

類型參數

T

包含在 collection 中的型別。The type that is contained in collection.

參數

collection
IEnumerable<T>

將從中取出 T 類型的項目以傳遞至 predicate 的集合。The collection from which elements of type T will be drawn to pass to predicate.

predicate
Predicate<T>

要評估 collection 中所有項目是否存在的函式。The function to evaluate for the existence of all the elements in collection.

傳回

只有在 predicateT 中所有 collection 型別的項目傳回 true 時,才為 truetrue if and only if predicate returns true for all elements of type T in collection.

例外狀況

collectionpredicatenullcollection or predicate is null.

範例

下列範例示範如何使用 ForAll 方法來判斷集合是否有 null 專案。The following example demonstrates how to use the ForAll method to determine whether a collection has a null element.

using System;
using System.Diagnostics.Contracts;
using System.Collections.Generic;
namespace AssumeEx
{
    class Program
    {
        // Start application with at least two arguments
        static void Main(string[] args)
        {
            args[1] = null;
            Contract.Requires(args != null && Contract.ForAll(0, args.Length, i => args[i] != null));
            // test the ForAll method.  This is only for purpose of demonstrating how ForAll works.
            CheckIndexes(args);
            Stack<string> numbers = new Stack<string>();
            numbers.Push("one");
            numbers.Push("two");
            numbers.Push(null);
            numbers.Push("four");
            numbers.Push("five");
            Contract.Requires(numbers != null && !Contract.ForAll(numbers, (String x) => x != null));
            // test the ForAll generic overload.  This is only for purpose of demonstrating how ForAll works.
            CheckTypeArray(numbers);
        }

        private static bool CheckIndexes(string[] args)
        {
            try
            {
                if (args != null && !Contract.ForAll(0, args.Length, i => args[i] != null))
                    throw new ArgumentException("The parameter array has a null element", "args");
                return true;
            }
            catch (ArgumentException e)
            {
                Console.WriteLine(e.Message);
                return false;
            }
        }
        private static bool CheckTypeArray(IEnumerable<String> xs)
        {
            try
            {
                if (xs != null && !Contract.ForAll(xs, (String x) => x != null))
                    throw new ArgumentException("The parameter array has a null element", "indexes");
                return true;
            }
            catch (ArgumentException e)
            {
                Console.WriteLine(e.Message);
                return false;
            }
        }
    }
}
Imports System.Diagnostics.Contracts
Imports System.Collections.Generic


Class Program

    ' Start application with at least two arguments.
    Shared Sub Main(ByVal args() As String)
        args(1) = Nothing
        Contract.Requires(Not (args Is Nothing) AndAlso Contract.ForAll(args, Function(s) s Is Nothing))
        ' test the ForAll method.  This is only for purpose of demonstrating how ForAll works.
        CheckIndexes(args)
        Dim numbers As New Stack(Of String)
        numbers.Push("one")
        numbers.Push("two")
        numbers.Push("three")
        numbers.Push("four")
        numbers.Push("five")

        Contract.Requires(Not (numbers Is Nothing) AndAlso Not Contract.ForAll(numbers, Function(s) s Is Nothing))
        ' test the ForAll generic overload. This is only for purpose of demonstrating how ForAll works.
        CheckTypeArray(numbers)

    End Sub


    Private Shared Function CheckIndexes(ByVal args() As String) As Boolean
        Try
            If Not (args Is Nothing) AndAlso Not Contract.ForAll(0, args.Length, Function(i) args(i) Is Nothing) Then
                Throw New ArgumentException("The parameter array has a null element", "args")
            End If
            Return True
        Catch e As ArgumentException
            Console.WriteLine(e.Message)
            Return False
        End Try

    End Function 'CheckIndexes

    Private Shared Function CheckTypeArray(ByVal xs As Stack(Of String)) As Boolean

        Try
            If Not (xs Is Nothing) AndAlso Not Contract.ForAll(xs, Function(s) s Is Nothing) Then

                Throw New ArgumentException("The parameter array has a null element", "Stack")
            End If
            Return True

        Catch e As ArgumentException
            Console.WriteLine(e.Message)
            Return False
        End Try

    End Function 'CheckTypeArray
End Class

另請參閱

適用於