ConcurrentDictionary<TKey,TValue>.TryRemove Metode

Definisi

Ruang nama:

System.Collections.Concurrent

Rakitan:

System.Collections.Concurrent.dll

Overload

TryRemove(TKey, TValue)	Mencoba untuk menghapus dan mengembalikan nilai yang memiliki kunci yang ditentukan dari ConcurrentDictionary<TKey,TValue>.
TryRemove(KeyValuePair<TKey,TValue>)	Menghapus kunci dan nilai dari kamus.

TryRemove(TKey, TValue)

Sumber:

ConcurrentDictionary.cs

Mencoba untuk menghapus dan mengembalikan nilai yang memiliki kunci yang ditentukan dari ConcurrentDictionary<TKey,TValue>.

public:
 bool TryRemove(TKey key, [Runtime::InteropServices::Out] TValue % value);

public bool TryRemove (TKey key, out TValue value);

member this.TryRemove : 'Key * 'Value -> bool

Public Function TryRemove (key As TKey, ByRef value As TValue) As Boolean

Parameter

key

TKey

Kunci elemen yang akan dihapus dan dikembalikan.

value

TValue

Ketika metode ini kembali, berisi objek yang dihapus dari ConcurrentDictionary<TKey,TValue>, atau nilai default jenis TValue jika key tidak ada.

Mengembalikan

Boolean

true jika objek berhasil dihapus; jika tidak, false.

Pengecualian

ArgumentNullException

keyadalah null.

Contoh

Contoh berikut menunjukkan cara memanggil ConcurrentDictionary<TKey,TValue>.TryRemove metode :

class CD_TryXYZ
{
        // Demonstrates:
        //      ConcurrentDictionary<TKey, TValue>.TryAdd()
        //      ConcurrentDictionary<TKey, TValue>.TryUpdate()
        //      ConcurrentDictionary<TKey, TValue>.TryRemove()
        static void Main()
        {
            int numFailures = 0; // for bookkeeping

            // Construct an empty dictionary
            ConcurrentDictionary<int, String> cd = new ConcurrentDictionary<int, string>();

            // This should work
            if (!cd.TryAdd(1, "one"))
            {
                Console.WriteLine("CD.TryAdd() failed when it should have succeeded");
                numFailures++;
            }

            // This shouldn't work -- key 1 is already in use
            if (cd.TryAdd(1, "uno"))
            {
                Console.WriteLine("CD.TryAdd() succeeded when it should have failed");
                numFailures++;
            }

            // Now change the value for key 1 from "one" to "uno" -- should work
            if (!cd.TryUpdate(1, "uno", "one"))
            {
                Console.WriteLine("CD.TryUpdate() failed when it should have succeeded");
                numFailures++;
            }

            // Try to change the value for key 1 from "eine" to "one"
            //    -- this shouldn't work, because the current value isn't "eine"
            if (cd.TryUpdate(1, "one", "eine"))
            {
                Console.WriteLine("CD.TryUpdate() succeeded when it should have failed");
                numFailures++;
            }

            // Remove key/value for key 1.  Should work.
            string value1;
            if (!cd.TryRemove(1, out value1))
            {
                Console.WriteLine("CD.TryRemove() failed when it should have succeeded");
                numFailures++;
            }

            // Remove key/value for key 1.  Shouldn't work, because I already removed it
            string value2;
            if (cd.TryRemove(1, out value2))
            {
                Console.WriteLine("CD.TryRemove() succeeded when it should have failed");
                numFailures++;
            }

            // If nothing went wrong, say so
            if (numFailures == 0) Console.WriteLine("  OK!");
        }
}

// Demonstrates:
//      ConcurrentDictionary<TKey, TValue>.TryAdd()
//      ConcurrentDictionary<TKey, TValue>.TryUpdate()
//      ConcurrentDictionary<TKey, TValue>.TryRemove()

let mutable numFailures = 0 // for bookkeeping

// Construct an empty dictionary
let cd = ConcurrentDictionary<int, string>()

// This should work
if cd.TryAdd(1, "one") |> not then
    printfn "CD.TryAdd() failed when it should have succeeded"
    numFailures <- numFailures + 1

// This shouldn't work -- key 1 is already in use
if cd.TryAdd(1, "uno") then
    printfn "CD.TryAdd() succeeded when it should have failed"
    numFailures <- numFailures + 1

// Now change the value for key 1 from "one" to "uno" -- should work
if cd.TryUpdate(1, "uno", "one") |> not then
    printfn "CD.TryUpdate() failed when it should have succeeded"
    numFailures <- numFailures + 1

// Try to change the value for key 1 from "eine" to "one"
//    -- this shouldn't work, because the current value isn't "eine"
if cd.TryUpdate(1, "one", "eine") then
    printfn "CD.TryUpdate() succeeded when it should have failed"
    numFailures <- numFailures + 1

// Remove key/value for key 1.  Should work.
let mutable value1 = ""

if cd.TryRemove(1, &value1) |> not then
    printfn "CD.TryRemove() failed when it should have succeeded"
    numFailures <- numFailures + 1

// Remove key/value for key 1.  Shouldn't work, because I already removed it
let mutable value2 = ""

if cd.TryRemove(1, &value2) then
    printfn "CD.TryRemove() succeeded when it should have failed"
    numFailures <- numFailures + 1

// If nothing went wrong, say so
if numFailures = 0 then
    printfn "  OK!"

'Imports System.Collections.Concurrent

Class CD_TryXYZ

    ' Demonstrates:
    ' ConcurrentDictionary<TKey, TValue>.TryAdd()
    ' ConcurrentDictionary<TKey, TValue>.TryUpdate()
    ' ConcurrentDictionary<TKey, TValue>.TryRemove()
    Shared Sub Main()
        Dim numFailures As Integer = 0
        ' for bookkeeping
        ' Construct an empty dictionary
        Dim cd As ConcurrentDictionary(Of Integer, [String]) = New ConcurrentDictionary(Of Integer, String)()

        ' This should work
        If Not cd.TryAdd(1, "one") Then
            Console.WriteLine("CD.TryAdd() failed when it should have succeeded")
            numFailures += 1
        End If

        ' This shouldn't work -- key 1 is already in use
        If cd.TryAdd(1, "uno") Then
            Console.WriteLine("CD.TryAdd() succeeded when it should have failed")
            numFailures += 1
        End If

        ' Now change the value for key 1 from "one" to "uno" -- should work
        If Not cd.TryUpdate(1, "uno", "one") Then
            Console.WriteLine("CD.TryUpdate() failed when it should have succeeded")
            numFailures += 1
        End If

        ' Try to change the value for key 1 from "eine" to "one" 
        ' -- this shouldn't work, because the current value isn't "eine"
        If cd.TryUpdate(1, "one", "eine") Then
            Console.WriteLine("CD.TryUpdate() succeeded when it should have failed")
            numFailures += 1
        End If

        ' Remove key/value for key 1. Should work.
        Dim value1 As String = ""
        If Not cd.TryRemove(1, value1) Then
            Console.WriteLine("CD.TryRemove() failed when it should have succeeded")
            numFailures += 1
        End If

        ' Remove key/value for key 1. Shouldn't work, because I already removed it
        Dim value2 As String = ""
        If cd.TryRemove(1, value2) Then
            Console.WriteLine("CD.TryRemove() succeeded when it should have failed")
            numFailures += 1
        End If

        ' If nothing went wrong, say so
        If numFailures = 0 Then
            Console.WriteLine(" OK!")
        End If
    End Sub
End Class

Lihat juga

• Koleksi yang Aman untuk Utas
• Petunjuk: Menambah dan Menghapus Item dari ConcurrentDictionary

TryRemove(KeyValuePair<TKey,TValue>)

Sumber:

ConcurrentDictionary.cs

Menghapus kunci dan nilai dari kamus.

public:
 bool TryRemove(System::Collections::Generic::KeyValuePair<TKey, TValue> item);

public bool TryRemove (System.Collections.Generic.KeyValuePair<TKey,TValue> item);

member this.TryRemove : System.Collections.Generic.KeyValuePair<'Key, 'Value> -> bool

Public Function TryRemove (item As KeyValuePair(Of TKey, TValue)) As Boolean

Parameter

item

KeyValuePair<TKey,TValue>

yang KeyValuePair<TKey,TValue> mewakili kunci dan nilai yang akan dihapus.

Mengembalikan

Boolean

true jika kunci dan nilai yang diwakili oleh item berhasil ditemukan dan dihapus; jika tidak, false.

Pengecualian

ArgumentNullException

Properti Key dari item adalah null.

Keterangan

Baik kunci dan nilai yang ditentukan harus cocok dengan entri dalam kamus agar dihapus.

Kunci dibandingkan menggunakan perbandingan kamus (atau pembanding default untuk TKey jika tidak ada perbandingan yang disediakan untuk kamus ketika dibangun). Nilai dibandingkan menggunakan pembanding default untuk TValue.