Marshal.ReadInt64 方法

参考

定义

命名空间:: System.Runtime.InteropServices

程序集:: System.Runtime.InteropServices.dll

程序集:: mscorlib.dll

程序集:: netstandard.dll

重要

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从非托管内存中读取一个 64 位带符号整数。支持从未对齐的内存位置进行读取。

重载

ReadInt64(IntPtr)	从非托管内存中读取一个 64 位带符号整数。
ReadInt64(IntPtr, Int32)	从非托管内存按给定的偏移量读取一个 64 位带符号整数。
ReadInt64(Object, Int32)	已过时. 从非托管内存按给定的偏移量读取一个 64 位带符号整数。

ReadInt64(IntPtr)

Source:: Marshal.cs

Source:: Marshal.cs

Source:: Marshal.cs

从非托管内存中读取一个 64 位带符号整数。

public:
 static long ReadInt64(IntPtr ptr);

[System.Security.SecurityCritical]
public static long ReadInt64 (IntPtr ptr);

public static long ReadInt64 (IntPtr ptr);

[<System.Security.SecurityCritical>]
static member ReadInt64 : nativeint -> int64

static member ReadInt64 : nativeint -> int64

Public Shared Function ReadInt64 (ptr As IntPtr) As Long

参数

ptr: IntPtr
nativeint

非托管内存中开始读取的地址。

Int64

从非托管内存中读取的 64 位带符号整数。

属性: SecurityCriticalAttribute

例外

AccessViolationException

ptr 不是识别的格式。

- 或 -

ptr 为 null。

- 或 -

ptr 无效。

示例

以下示例演示如何使用 ReadInt64 和 WriteInt64 方法读取和写入非托管数组。

static void ReadWriteInt64()
{
    // Allocate unmanaged memory. 
    int elementSize = 8;
    IntPtr unmanagedArray = Marshal.AllocHGlobal(10 * elementSize);

    // Set the 10 elements of the C-style unmanagedArray
    for (int i = 0; i < 10; i++)
    {
        Marshal.WriteInt64(unmanagedArray, i * elementSize, ((Int64)(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.ReadInt64(unmanagedArray, i * elementSize));
    }

    Marshal.FreeHGlobal(unmanagedArray);

    Console.WriteLine("Done. Press Enter to continue.");
    Console.ReadLine();
}

Sub ReadWriteInt64()
    ' Allocate unmanaged memory. 
    Dim elementSize As Integer = 8
    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.WriteInt64(unmanagedArray, i * elementSize, CType(i + 1, Int64))
    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.ReadInt64(unmanagedArray, i * elementSize))
    Next i

    Marshal.FreeHGlobal(unmanagedArray)

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

下面的示例演示如何使用 ReadInt64 方法读取非托管 __int64 变量的值。

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



void main()
{
    // Create an unmanaged __int64.
    __int64 myVal = 42;

    // Read the value as a managed Int64.
    Int64 ^ myManagedVal = Marshal::ReadInt64((IntPtr) &myVal);

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

注解

ReadInt64 具有 0 的隐式偏移量。此方法允许与非托管 C 样式 Int64 数组直接交互，从而消除了在读取其元素值之前使用 Marshal.Copy) 复制到单独托管数组 (整个非托管数组的开销。

支持从未对齐的内存位置进行读取。

另请参阅

Copy(Int32[], Int32, IntPtr, Int32)

适用于

ReadInt64(IntPtr, Int32)

Source:: Marshal.cs

Source:: Marshal.cs

Source:: Marshal.cs

从非托管内存按给定的偏移量读取一个 64 位带符号整数。

public:
 static long ReadInt64(IntPtr ptr, int ofs);

[System.Security.SecurityCritical]
public static long ReadInt64 (IntPtr ptr, int ofs);

public static long ReadInt64 (IntPtr ptr, int ofs);

[<System.Security.SecurityCritical>]
static member ReadInt64 : nativeint * int -> int64

static member ReadInt64 : nativeint * int -> int64

Public Shared Function ReadInt64 (ptr As IntPtr, ofs As Integer) As Long

参数

ptr: IntPtr
nativeint

非托管内存中开始读取的基址。

ofs: Int32

额外的字节偏移量，在读取前添加到 ptr 参数中。

Int64

从非托管内存按给定的偏移量读取的 64 位带符号整数。

属性: SecurityCriticalAttribute

例外

AccessViolationException

基址 (ptr) 加上偏移字节 (ofs) 可产生空或无效地址。

示例

以下示例演示如何使用 ReadInt64 和 WriteInt64 方法读取和写入非托管数组。

static void ReadWriteInt64()
{
    // Allocate unmanaged memory. 
    int elementSize = 8;
    IntPtr unmanagedArray = Marshal.AllocHGlobal(10 * elementSize);

    // Set the 10 elements of the C-style unmanagedArray
    for (int i = 0; i < 10; i++)
    {
        Marshal.WriteInt64(unmanagedArray, i * elementSize, ((Int64)(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.ReadInt64(unmanagedArray, i * elementSize));
    }

    Marshal.FreeHGlobal(unmanagedArray);

    Console.WriteLine("Done. Press Enter to continue.");
    Console.ReadLine();
}

Sub ReadWriteInt64()
    ' Allocate unmanaged memory. 
    Dim elementSize As Integer = 8
    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.WriteInt64(unmanagedArray, i * elementSize, CType(i + 1, Int64))
    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.ReadInt64(unmanagedArray, i * elementSize))
    Next i

    Marshal.FreeHGlobal(unmanagedArray)

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

下面的示例演示如何使用 ReadInt64 方法读取非托管 __int64 变量的值。


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



void main()
{
    // Create an unmanaged __int64 pointer.
    __int64 * myVal;
    __int64 tmp = 42;
    // Initialize it to another value.
    myVal = &tmp;

    // Read value as a managed Int64.
    Int64 ^ myManagedVal = Marshal::ReadInt64((IntPtr) myVal, 0);

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

注解

ReadInt64 允许与非托管的 64 位有符号数组直接交互，从而消除了在读取其元素值之前使用 Marshal.Copy) 将整个非托管数组 (复制到单独的托管数组的开销。

支持从未对齐的内存位置进行读取。

另请参阅

适用于

ReadInt64(Object, Int32)

Source:: Marshal.CoreCLR.cs

Source:: Marshal.CoreCLR.cs

Source:: Marshal.CoreCLR.cs

注意

ReadInt64(Object, Int32) may be unavailable in future releases.

从非托管内存按给定的偏移量读取一个 64 位带符号整数。

public:
 static long ReadInt64(System::Object ^ ptr, int ofs);

[System.Obsolete("ReadInt64(Object, Int32) may be unavailable in future releases.")]
[System.Security.SecurityCritical]
public static long ReadInt64 (object ptr, int ofs);

[System.Obsolete("ReadInt64(Object, Int32) may be unavailable in future releases.")]
public static long ReadInt64 (object ptr, int ofs);

public static long ReadInt64 (object ptr, int ofs);

[System.Security.SecurityCritical]
public static long ReadInt64 (object ptr, int ofs);

[<System.Obsolete("ReadInt64(Object, Int32) may be unavailable in future releases.")>]
[<System.Security.SecurityCritical>]
static member ReadInt64 : obj * int -> int64

[<System.Obsolete("ReadInt64(Object, Int32) may be unavailable in future releases.")>]
static member ReadInt64 : obj * int -> int64

static member ReadInt64 : obj * int -> int64

[<System.Security.SecurityCritical>]
static member ReadInt64 : obj * int -> int64

Public Shared Function ReadInt64 (ptr As Object, ofs As Integer) As Long

参数

ptr: Object

非托管内存中源对象的基址。

ofs: Int32

额外的字节偏移量，在读取前添加到 ptr 参数中。

Int64

从非托管内存按给定的偏移量读取的 64 位带符号整数。

属性: ObsoleteAttribute SecurityCriticalAttribute

例外

AccessViolationException

基址 (ptr) 加上偏移字节 (ofs) 可产生空或无效地址。

ArgumentException

ptr 是 ArrayWithOffset 对象。此方法不接受 ArrayWithOffset 参数。

注解

ReadInt64 允许与非托管的 64 位有符号数组直接交互，从而消除了在读取其元素值之前使用 Marshal.Copy) 将整个非托管数组 (复制到单独的托管数组的开销。

支持从未对齐的内存位置进行读取。

另请参阅

Copy(Int32[], Int32, IntPtr, Int32)

适用于

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通过

ReadInt64(IntPtr)

参数

返回

例外

示例

注解

另请参阅

适用于

ReadInt64(IntPtr, Int32)

参数

返回

例外

示例

注解

另请参阅

适用于

ReadInt64(Object, Int32)

参数

返回

例外

注解

另请参阅

适用于