线程问题（线程间操作无效: 从不是创建控件“results”的线程访问它。）
private void button1_Click(object sender, EventArgs e)
{
results.Items.Clear();
string addr = address.Text;
Object state = new Object();

OnResovled = new AsyncCallback(Resolved);


Dns.BeginResolve(addr, OnResovled, state);
}

private void Resolved(IAsyncResult ar)
{
string buffer;
IPHostEntry iphe = Dns.EndResolve(ar);
buffer = "Host name:" + iphe.HostName;
results.Items.Add(buffer);

foreach (string alias in iphe.Aliases)
{
buffer = "Alias:" + alias;
results.Items.Add(buffer);

}

foreach (IPAddress addrs in iphe.AddressList)
{
buffer = "Address:" + addrs.ToString();
results.Items.Add(buffer);
}
}

运行报错：线程间操作无效: 从不是创建控件“results”的线程访问它。


[解决办法]

C# code

 private void Resolved(IAsyncResult ar) { if (this.InvokeRequired){  OnResovled = new AsyncCallback(Resolved);   this.Invoke(OnResovled , new object[] { ar});}else{                       string buffer;             IPHostEntry iphe = Dns.EndResolve(ar);             buffer = "Host name:" + iphe.HostName;             results.Items.Add(buffer);             foreach (string alias in iphe.Aliases)             {                 buffer = "Alias:" + alias;                 results.Items.Add(buffer);             }             foreach (IPAddress addrs in iphe.AddressList)             {                 buffer = "Address:" + addrs.ToString();                 results.Items.Add(buffer);             }  }}