共用方式為


Marshal.ReadByte 方法

定義

從 Unmanaged 記憶體讀取單一位元組。 支援讀取未配置的記憶體位置。

多載

ReadByte(IntPtr, Int32)

從 Unmanaged 記憶體讀取在指定位移 (或索引) 的單一位元組。

ReadByte(Object, Int32)
已淘汰.

從 Unmanaged 記憶體讀取在指定位移 (或索引) 的單一位元組。

ReadByte(IntPtr)

從 Unmanaged 記憶體讀取單一位元組。

ReadByte(IntPtr, Int32)

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

從 Unmanaged 記憶體讀取在指定位移 (或索引) 的單一位元組。

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

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 記憶體中指定位移處讀取的位元組。

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 WriteByte 方法來讀取和寫入 Unmanaged 陣列ReadByte

static void ReadWriteByte()
{
    // Allocate unmanaged memory. 
    int elementSize = 1;
    IntPtr unmanagedArray = Marshal.AllocHGlobal(10 * elementSize);

    // Set the 10 elements of the C-style unmanagedArray
    for (int i = 0; i < 10; i++)
    {
        Marshal.WriteByte(unmanagedArray, i * elementSize, ((Byte)(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.ReadByte(unmanagedArray, i * elementSize));
    }

    Marshal.FreeHGlobal(unmanagedArray);

    Console.WriteLine("Done. Press Enter to continue.");
    Console.ReadLine();
}
Sub ReadWriteByte()
    ' Allocate unmanaged memory. 
    Dim elementSize As Integer = 1
    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.WriteByte(unmanagedArray, i * elementSize, CType(i + 1, Byte))
    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.ReadByte(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 ReadByte 方法來讀取 Unmanaged 字元的值。


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



void main()
{
    // Create an unmanaged byte.
    const char * myString = "bB";

    // Read the second character of the c string as a managed byte.
        Byte ^ myManagedByte = Marshal::ReadByte((IntPtr) (char *) myString, 1);

    // Display the byte to the console.
    Console::WriteLine(myManagedByte);
}

備註

ReadByte 可讓您與 Unmanaged C 樣式位元組陣列直接互動,而不需要先使用 Marshal.Copy) 將整個 Unmanaged 數位複製到個別 Managed 陣列,再讀取其元素值,即可將整個 Unmanaged 陣列複製 (。

支援讀取未配置的記憶體位置。

另請參閱

適用於

ReadByte(Object, Int32)

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

警告

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

從 Unmanaged 記憶體讀取在指定位移 (或索引) 的單一位元組。

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

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位元組。

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

ReadByte 可讓您與 Unmanaged C 樣式位元組陣列直接互動,而不需要先使用 Marshal.Copy) 將整個 Unmanaged 數位複製到個別 Managed 陣列,再讀取其元素值,即可將整個 Unmanaged 陣列複製 (。

支援讀取未配置的記憶體位置。

另請參閱

適用於

ReadByte(IntPtr)

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

從 Unmanaged 記憶體讀取單一位元組。

public:
 static System::Byte ReadByte(IntPtr ptr);
[System.Security.SecurityCritical]
public static byte ReadByte (IntPtr ptr);
public static byte ReadByte (IntPtr ptr);
[<System.Security.SecurityCritical>]
static member ReadByte : nativeint -> byte
static member ReadByte : nativeint -> byte
Public Shared Function ReadByte (ptr As IntPtr) As Byte

參數

ptr
IntPtr

nativeint

從 Unmanaged 記憶體中讀取的位址。

傳回

從 Unmanaged 記憶體讀取的位元組。

屬性

例外狀況

ptr 不是可辨認的格式。

-或-

ptrnull

-或-

ptr 無效。

範例

下列範例會建立 Unmanaged 記憶體區塊、將位元組寫入 Unmanaged 記憶體、從 Unmanaged 記憶體讀取位元元組,然後處置 Unmanaged 記憶體。

using System;
using System.Runtime.InteropServices;

 class Example
 {
     static void Main(string[] args)
     {
          // Allocate 1 byte of unmanaged memory.
          IntPtr hGlobal = Marshal.AllocHGlobal(1);

          // Create a new byte.
          byte b = 1;
          Console.WriteLine("Byte written to unmanaged memory: " + b);

          // Write the byte to unmanaged memory.
          Marshal.WriteByte(hGlobal, b);

          // Read byte from unmanaged memory.
          byte c = Marshal.ReadByte(hGlobal);
          Console.WriteLine("Byte read from unmanaged memory: " + c);

          // Free the unmanaged memory.
          Marshal.FreeHGlobal(hGlobal);
          Console.WriteLine("Unmanaged memory was disposed.");
     }
}
Imports System.Runtime.InteropServices

Module Example
    Sub Main()
         ' Allocate 1 byte of unmanaged memory.
         Dim hGlobal As IntPtr = Marshal.AllocHGlobal(1)
         
         ' Create a new byte.
         Dim b As Byte = 1
         
         Console.WriteLine("Byte written to unmanaged memory: {0}", b)
         
         ' Write the byte to unmanaged memory.
         Marshal.WriteByte(hGlobal, b)
         
         ' Read byte from unmanaged memory.
         Dim c As Byte = Marshal.ReadByte(hGlobal)
         Console.WriteLine("Byte read from unmanaged memory: {0}", c)
         
         ' Free the unmanaged memory.
         Marshal.FreeHGlobal(hGlobal)
         Console.WriteLine("Unmanaged memory was disposed.")
    End Sub
End Module

下列範例示範如何使用 ReadByte 方法來讀取 Unmanaged 字元的值。


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



void main()
{
    // Create an unmanaged byte.
    const char * myString = "b";

    // Read the c string as a managed byte.
        Byte ^ myManagedByte = Marshal::ReadByte((IntPtr) (char *) myString);

    // Display the byte to the console.
    Console::WriteLine(myManagedByte);
}

備註

ReadByte 具有 0 的隱含位移。 這個方法可讓您與 Unmanaged C 樣式位元組陣列直接互動,而不需要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