共用方式為


Marshal.ReadInt32 方法

定義

從 Unmanaged 記憶體讀取 32 位元帶正負號的整數。 支援讀取未配置的記憶體位置。

多載

ReadInt32(IntPtr)

從 Unmanaged 記憶體讀取 32 位元帶正負號的整數。

ReadInt32(IntPtr, Int32)

從 Unmanaged 記憶體中指定位移處讀取 32 位元帶正負號的整數。

ReadInt32(Object, Int32)
已淘汰.

從 Unmanaged 記憶體中指定位移處讀取 32 位元帶正負號的整數。

ReadInt32(IntPtr)

來源:
Marshal.cs
來源:
Marshal.cs
來源:
Marshal.cs

從 Unmanaged 記憶體讀取 32 位元帶正負號的整數。

public:
 static int ReadInt32(IntPtr ptr);
[System.Security.SecurityCritical]
public static int ReadInt32 (IntPtr ptr);
public static int ReadInt32 (IntPtr ptr);
[<System.Security.SecurityCritical>]
static member ReadInt32 : nativeint -> int
static member ReadInt32 : nativeint -> int
Public Shared Function ReadInt32 (ptr As IntPtr) As Integer

參數

ptr
IntPtr

nativeint

從 Unmanaged 記憶體中讀取的位址。

傳回

從 Unmanaged 記憶體讀取的 32 位元帶正負號的整數。

屬性

例外狀況

ptr 不是可辨認的格式。

-或-

ptrnull

-或-

ptr 無效。

範例

下列範例示範如何使用 和 WriteInt32 方法來讀取和寫入 Unmanaged 陣列ReadInt32

static void ReadWriteInt32()
{
    // Allocate unmanaged memory. 
    int elementSize = 4;
    IntPtr unmanagedArray = Marshal.AllocHGlobal(10 * elementSize);

    // Set the 10 elements of the C-style unmanagedArray
    for (int i = 0; i < 10; i++)
    {
        Marshal.WriteInt32(unmanagedArray, i * elementSize, ((Int32)(i + 1)));
    }
    Console.WriteLine("Unmanaged memory written.");

    Console.WriteLine("Reading unmanaged memory:");
    // Print the 10 elements of the C-style unmanagedArray
    for (int i = 0; i < 10; i++)
    {
        Console.WriteLine(Marshal.ReadInt32(unmanagedArray, i * elementSize));
    }

    Marshal.FreeHGlobal(unmanagedArray);

    Console.WriteLine("Done. Press Enter to continue.");
    Console.ReadLine();
}
Sub ReadWriteInt32()
    ' Allocate unmanaged memory. 
    Dim elementSize As Integer = 4
    Dim unmanagedArray As IntPtr = Marshal.AllocHGlobal(10 * elementSize)

    ' Set the 10 elements of the C-style unmanagedArray
    For i As Integer = 0 To 9
        Marshal.WriteInt32(unmanagedArray, i * elementSize, CType(i + 1, Int32))
    Next i
    Console.WriteLine("Unmanaged memory written.")

    Console.WriteLine("Reading unmanaged memory:")
    ' Print the 10 elements of the C-style unmanagedArray
    For i As Integer = 0 To 9
        Console.WriteLine(Marshal.ReadInt32(unmanagedArray, i * elementSize))
    Next i

    Marshal.FreeHGlobal(unmanagedArray)

    Console.WriteLine("Done. Press Enter to continue.")
    Console.ReadLine()
End Sub

下列範例示範如何使用 ReadInt32 方法來讀取 Unmanaged int 變數的值。

using namespace System;
using namespace System::Runtime::InteropServices;



void main()
{
    // Create an unmanaged integer.
    int myVal = 42;

    // Read the int as a managed Int32.
        Int32 ^ myManagedVal = Marshal::ReadInt32((IntPtr) &myVal);

    // Display the value to the console.
    Console::WriteLine(myManagedVal);
}

備註

ReadInt32 具有 0 的隱含位移。 這個方法可讓您直接與 Unmanaged C 樣式 Int32 數位互動,避免在讀取其元素值之前,先將 Marshal.Copy 整個 Unmanaged 陣組複製 () (。

支援讀取未配置的記憶體位置。

另請參閱

適用於

ReadInt32(IntPtr, Int32)

來源:
Marshal.cs
來源:
Marshal.cs
來源:
Marshal.cs

從 Unmanaged 記憶體中指定位移處讀取 32 位元帶正負號的整數。

public:
 static int ReadInt32(IntPtr ptr, int ofs);
[System.Security.SecurityCritical]
public static int ReadInt32 (IntPtr ptr, int ofs);
public static int ReadInt32 (IntPtr ptr, int ofs);
[<System.Security.SecurityCritical>]
static member ReadInt32 : nativeint * int -> int
static member ReadInt32 : nativeint * int -> int
Public Shared Function ReadInt32 (ptr As IntPtr, ofs As Integer) As Integer

參數

ptr
IntPtr

nativeint

從 Unmanaged 記憶體中讀取的基底位址 (Base Address)。

ofs
Int32

額外的位元組位移,會先加入至參數 ptr,然後再進行讀取。

傳回

從 Unmanaged 記憶體讀取的 32 位元帶正負號的整數。

屬性

例外狀況

基底位址 (ptr) 加上位移位元組 (ofs) 會產生 Null 或無效的位址。

範例

下列範例示範如何使用 和 WriteInt32 方法來讀取和寫入 Unmanaged 陣列ReadInt32

static void ReadWriteInt32()
{
    // Allocate unmanaged memory. 
    int elementSize = 4;
    IntPtr unmanagedArray = Marshal.AllocHGlobal(10 * elementSize);

    // Set the 10 elements of the C-style unmanagedArray
    for (int i = 0; i < 10; i++)
    {
        Marshal.WriteInt32(unmanagedArray, i * elementSize, ((Int32)(i + 1)));
    }
    Console.WriteLine("Unmanaged memory written.");

    Console.WriteLine("Reading unmanaged memory:");
    // Print the 10 elements of the C-style unmanagedArray
    for (int i = 0; i < 10; i++)
    {
        Console.WriteLine(Marshal.ReadInt32(unmanagedArray, i * elementSize));
    }

    Marshal.FreeHGlobal(unmanagedArray);

    Console.WriteLine("Done. Press Enter to continue.");
    Console.ReadLine();
}
Sub ReadWriteInt32()
    ' Allocate unmanaged memory. 
    Dim elementSize As Integer = 4
    Dim unmanagedArray As IntPtr = Marshal.AllocHGlobal(10 * elementSize)

    ' Set the 10 elements of the C-style unmanagedArray
    For i As Integer = 0 To 9
        Marshal.WriteInt32(unmanagedArray, i * elementSize, CType(i + 1, Int32))
    Next i
    Console.WriteLine("Unmanaged memory written.")

    Console.WriteLine("Reading unmanaged memory:")
    ' Print the 10 elements of the C-style unmanagedArray
    For i As Integer = 0 To 9
        Console.WriteLine(Marshal.ReadInt32(unmanagedArray, i * elementSize))
    Next i

    Marshal.FreeHGlobal(unmanagedArray)

    Console.WriteLine("Done. Press Enter to continue.")
    Console.ReadLine()
End Sub

下列範例示範如何使用 ReadInt32 方法來讀取 Unmanaged int 變數的值。

using namespace System;
using namespace System::Runtime::InteropServices;



void main()
{
    // Create an unmanaged int pointer.
    int * myVal;
    int tmp = 42;
    // Initialize it to another value.
    myVal = &tmp;

    // Read value as a managed Int32.
    Int32 ^ myManagedVal = Marshal::ReadInt32((IntPtr) myVal, 0);

    // Display the value to the console.
    Console::WriteLine(myManagedVal);
}

備註

ReadInt32 可讓您直接與 Unmanaged 32 位帶正負號的陣列互動,避免在讀取其元素值之前,先將 Marshal.Copy 整個 Unmanaged 數位複製 () (。

支援讀取未配置的記憶體位置。

另請參閱

適用於

ReadInt32(Object, Int32)

來源:
Marshal.CoreCLR.cs
來源:
Marshal.CoreCLR.cs
來源:
Marshal.CoreCLR.cs

警告

ReadInt32(Object, Int32) may be unavailable in future releases.

從 Unmanaged 記憶體中指定位移處讀取 32 位元帶正負號的整數。

public:
 static int ReadInt32(System::Object ^ ptr, int ofs);
[System.Obsolete("ReadInt32(Object, Int32) may be unavailable in future releases.")]
[System.Security.SecurityCritical]
public static int ReadInt32 (object ptr, int ofs);
[System.Obsolete("ReadInt32(Object, Int32) may be unavailable in future releases.")]
public static int ReadInt32 (object ptr, int ofs);
public static int ReadInt32 (object ptr, int ofs);
[System.Security.SecurityCritical]
public static int ReadInt32 (object ptr, int ofs);
[<System.Obsolete("ReadInt32(Object, Int32) may be unavailable in future releases.")>]
[<System.Security.SecurityCritical>]
static member ReadInt32 : obj * int -> int
[<System.Obsolete("ReadInt32(Object, Int32) may be unavailable in future releases.")>]
static member ReadInt32 : obj * int -> int
static member ReadInt32 : obj * int -> int
[<System.Security.SecurityCritical>]
static member ReadInt32 : obj * int -> int
Public Shared Function ReadInt32 (ptr As Object, ofs As Integer) As Integer

參數

ptr
Object

來源物件之 Unmanaged 記憶體中的基底位址。

ofs
Int32

額外的位元組位移,會先加入至參數 ptr,然後再進行讀取。

傳回

從 Unmanaged 記憶體中指定位移處讀取的 32 位元帶正負號的整數。

屬性

例外狀況

基底位址 (ptr) 加上位移位元組 (ofs) 會產生 Null 或無效的位址。

ptrArrayWithOffset 物件。 這個方法不會接受 ArrayWithOffset 參數。

備註

ReadInt32 可讓您直接與 Unmanaged 32 位帶正負號的陣列互動,避免在讀取其元素值之前,先將 Marshal.Copy 整個 Unmanaged 數位複製 () (。

支援讀取未配置的記憶體位置。

另請參閱

適用於