当前位置: 首页>>代码示例>>C#>>正文


C# IntPtr.Zero字段代码示例

本文整理汇总了C#中System.IntPtr.Zero字段的典型用法代码示例。如果您正苦于以下问题:C# IntPtr.Zero字段的具体用法?C# IntPtr.Zero怎么用?C# IntPtr.Zero使用的例子?那么恭喜您, 这里精选的字段代码示例或许可以为您提供帮助。您也可以进一步了解该字段所在System.IntPtr的用法示例。


在下文中一共展示了IntPtr.Zero字段的2个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的C#代码示例。

示例1: CreateFile

//引入命名空间
using Microsoft.Win32.SafeHandles;
using System;
using System.Runtime.InteropServices;

public class Example
{
   private const uint GENERIC_READ = 0x80000000;
   private const uint OPEN_EXISTING = 3; 
   private const uint FILE_ATTRIBUTE_NORMAL = 128;
   private const uint FILE_FLAG_OVERLAPPED = 0x40000000;

   [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
   private static extern Microsoft.Win32.SafeHandles.SafeFileHandle CreateFile(
            string lpFileName, System.UInt32 dwDesiredAccess, System.UInt32 dwShareMode, 
            IntPtr pSecurityAttributes, System.UInt32 dwCreationDisposition, 
            System.UInt32 dwFlagsAndAttributes, IntPtr hTemplateFile);

   public static void Main()
   {
      SafeFileHandle hnd = CreateFile("CallOfTheWild.txt", GENERIC_READ, 0, 
                                      IntPtr.Zero, OPEN_EXISTING,
                                      FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED, 
                                      IntPtr.Zero);
      if (hnd.IsInvalid) {
            Exception ex = Marshal.GetExceptionForHR(Marshal.GetHRForLastWin32Error());
            Console.WriteLine("Attempt to open file failed:");
            Console.WriteLine("  {0}", ex.Message);
            return;           
      }                        
      else {
         Console.WriteLine("File successfully opened.");
         hnd.Close();     
      }
   }
}
开发者ID:.NET开发者,项目名称:System,代码行数:36,代码来源:IntPtr.Zero

输出:

Attempt to open file failed:
The system cannot find the file specified. (Exception from HRESULT: 0x80070002)

示例2: GetWindow

//引入命名空间
using System;
using System.Runtime.InteropServices;

public class Example
{
   private const int GW_OWNER = 4;
    
   [DllImport("user32", CharSet=CharSet.Auto, SetLastError=true, ExactSpelling=true)]
   public static extern IntPtr GetWindow(IntPtr hwnd, int wFlag);   
   
   public static void Main()
   {
      IntPtr hwnd = new IntPtr(3);
      IntPtr hOwner = GetWindow(hwnd, GW_OWNER);
      if (hOwner == IntPtr.Zero)
         Console.WriteLine("Window not found.");
   }
}
开发者ID:.NET开发者,项目名称:System,代码行数:19,代码来源:IntPtr.Zero

输出:

Window not found.


注:本文中的System.IntPtr.Zero字段示例由纯净天空整理自Github/MSDocs等开源代码及文档管理平台,相关代码片段筛选自各路编程大神贡献的开源项目,源码版权归原作者所有,传播和使用请参考对应项目的License;未经允许,请勿转载。