C# SharpPcap跨线程操作无效
C# SharpPcap跨线程操作无效
提问于 2010-02-11 20:17:32
嗨，我正在尝试将Example3中的SharpPcap新版本SharpPcap-2.2.0rc1.src中的数据包捕获从控制台应用程序转换为。
当我试图将数据包添加到ListView控件中时，我面临一个问题，我将得到一个错误，即：
(跨线程操作无效:从创建线程的线程以外的线程访问控件'listViewPackets‘。)
在这一行：
listViewPackets.Items.Add(e.Packet.ToString());
有什么解决这个问题的建议吗？？
这是我的代码：
using SharpPcap;
namespace Packets
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
// Retrieve the device list
private void btnLiDevicest_Click(object sender, EventArgs e)
{
var devices = LivePcapDeviceList.Instance;
// If no devices were found print an error
if (devices.Count < 1)
{
MessageBox.Show("No devices were found on this machine");
return;
}
int i = 0;
// Print out the devices
foreach (LivePcapDevice dev in devices)
{
///* Description */
//Console.WriteLine("{0}) {1} {2}", i, dev.Name, dev.Description);
cmbListDevice.Items.Add(dev.Name + " " + dev.Description);
i++;
}
LivePcapDevice device = devices[1];
// Register our handler function to the 'packet arrival' event
device.OnPacketArrival += new PacketArrivalEventHandler(device_OnPacketArrival);
// Open the device for capturing
int readTimeoutMilliseconds = 1000;
device.Open(DeviceMode.Promiscuous, readTimeoutMilliseconds);
device.StartCapture();
}
//Console.WriteLine();
//Console.WriteLine("-- Listening on {0}, hit 'Enter' to stop...",
// device.Description);
/// <summary>
/// Prints the time and length of each received packet
/// </summary>
///
protected void device_OnPacketArrival(object sender, CaptureEventArgs e)
{
DateTime time = e.Packet.PcapHeader.Date;
uint len = e.Packet.PcapHeader.PacketLength;
//Console.WriteLine("{0}:{1}:{2},{3} Len={4}",
// time.Hour, time.Minute, time.Second, time.Millisecond, len);
// Console.WriteLine(e.Packet.ToString());
listViewPackets.Items.Add(e.Packet.ToString());
}
}
}....这是原始代码：
using System;
using System.Collections.Generic;
using SharpPcap;
namespace SharpPcap.Test.Example3
{
/// <summary>
/// Basic capture example
/// </summary>
public class BasicCap
{
public static void Main(string[] args)
{
// Print SharpPcap version
string ver = SharpPcap.Version.VersionString;
Console.WriteLine("SharpPcap {0}, Example3.BasicCap.cs", ver);
// Retrieve the device list
var devices = LivePcapDeviceList.Instance;
// If no devices were found print an error
if(devices.Count < 1)
{
Console.WriteLine("No devices were found on this machine");
return;
}
Console.WriteLine();
Console.WriteLine("The following devices are available on this machine:");
Console.WriteLine("----------------------------------------------------");
Console.WriteLine();
int i = 0;
// Print out the devices
foreach(LivePcapDevice dev in devices)
{
/* Description */
Console.WriteLine("{0}) {1} {2}", i, dev.Name, dev.Description);
i++;
}
Console.WriteLine();
Console.Write("-- Please choose a device to capture: ");
i = int.Parse( Console.ReadLine() );
LivePcapDevice device = devices[i];
// Register our handler function to the 'packet arrival' event
device.OnPacketArrival +=
new PacketArrivalEventHandler( device_OnPacketArrival );
// Open the device for capturing
int readTimeoutMilliseconds = 1000;
device.Open(DeviceMode.Promiscuous, readTimeoutMilliseconds);
Console.WriteLine();
Console.WriteLine("-- Listening on {0}, hit 'Enter' to stop...",
device.Description);
// Start the capturing process
device.StartCapture();
// Wait for 'Enter' from the user.
Console.ReadLine();
// Stop the capturing process
device.StopCapture();
Console.WriteLine("-- Capture stopped.");
// Print out the device statistics
Console.WriteLine(device.Statistics().ToString());
// Close the pcap device
device.Close();
}
/// <summary>
/// Prints the time and length of each received packet
/// </summary>
private static void device_OnPacketArrival(object sender, CaptureEventArgs e)
{
DateTime time = e.Packet.PcapHeader.Date;
uint len = e.Packet.PcapHeader.PacketLength;
Console.WriteLine("{0}:{1}:{2},{3} Len={4}",
time.Hour, time.Minute, time.Second, time.Millisecond, len);
Console.WriteLine(e.Packet.ToString());
}
}
}回答 2
Stack Overflow用户
回答已采纳
发布于 2010-02-11 20:20:54
从另一个线程调用控件时：
if (listView1.InvokeRequired)
{
listView1.BeginInvoke(new MethodInvoker(
() => /*whatever you want with listview */));
}
else
{
/* whatever you want with listview */
}如果您确信它总是在另一个线程上，那么只需忘记If / use并使用调用即可。
编辑：
所以在你的情况下，它看起来是：
if(listView1.InvokeRequired)
{
listView1.BeginInvoke(new MethodInvoker(
() => listViewPackets.Items.Add(e.Packet.ToString()) ));
}
else
{
listViewPackets.Items.Add(e.Packet.ToString());
}(如果它总是在不同的线程上运行，也可以只调用BeginInvoke )
编辑2您会注意到Shane使用Invoke，我使用BeginInvoke。我把它当作习惯的力量。使用Invoke将阻塞UI线程，如果您执行的操作花费的时间更长，则使用BeginInvoke异步执行UI的更新。
Stack Overflow用户
发布于 2010-02-11 20:19:19
您需要使用调用，因为数据包来自不同的线程。除了在线程上创建UI控件之外，不能在线程上修改UI控件。Invoke将在UI线程上执行给定的委托。例如，您可以这样做：
this.Invoke(new MethodInvoker(() => listViewPackets.Items.Add(e.Packet.ToString())), null);
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/2247427
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