有人可以解释我如何从此代码执行异步任务吗？ 目前代码确实可以正常工作，但是我已经尝试使其异步了吗？因此，应用在执行时不会冻结，但不会成功。
public WebpageLocalScanner()
{
InitializeComponent();
InitializeListView();
}
internal string GetType(string ip, int port)
{
try
{
if (port == 1234 || port == 4321)
{
string urlAddress = string.Format("http://{0}", ip);
string text = this.GetHttpData(ip, 80, urlAddress, 5120).ToUpper();
if (text.Contains("<HTML>"))
{
return "Webpage is here";
}
}
}
catch (Exception)
{
}
return string.Empty;
}
public void AddItem() {
listView1.Items.Clear();
int froms192 = Convert.ToInt32(tB1.Text);
int froms168 = Convert.ToInt32(tB2.Text);
int froms1a = Convert.ToInt32(tB3.Text);
int froms1b = Convert.ToInt32(tB4.Text);
int fromports = Convert.ToInt32(tBp1.Text);
int toports = Convert.ToInt32(tBp2.Text);
string FromIP = froms192 + "." + froms168 + "." + froms1a + "." + froms1b;
int FromPort = fromports;
int ToPort = toports;
int tos192 = Convert.ToInt32(tB5.Text);
int tos168 = Convert.ToInt32(tB6.Text);
int tos1a = Convert.ToInt32(tB7.Text);
int tos1b = Convert.ToInt32(tB8.Text);
string ToIP = froms192 + "." + froms168 + "." + froms1a + "." + froms1b;
if (froms1a < tos1a || froms1b < tos1b)
{
for (int i = froms1b; i <= tos1b; i++)
{
for (int u = froms1a; u <= tos1a; u++)
{
for (int p = fromports; p <= toports; p++)
{
string GenIP = froms192 + "." + froms168 + "." + u + "." + i;
string result = GetType(GenIP, p);
if (result != null) {
string[] row = { Convert.ToString(GenIP), Convert.ToString(fromports), Convert.ToString(result), Convert.ToString(tos1a), Convert.ToString(tos1a) };
var listViewItem = new ListViewItem(row);
listView1.Items.Add(listViewItem);
};
}
}
}
}
}
private void InitializeListView()
{
// Set the view to show details.
listView1.View = View.Details;
// Allow the user to edit item text.
listView1.LabelEdit = true;
// Allow the user to rearrange columns.
listView1.AllowColumnReorder = true;
// Display check boxes.
// listView1.CheckBoxes = true;
// Select the item and subitems when selection is made.
listView1.FullRowSelect = true;
// Display grid lines.
listView1.GridLines = true;
// Sort the items in the list in ascending order.
listView1.Sorting = SortOrder.Ascending;
// Attach Subitems to the ListView
listView1.Columns.Add("IP", 100, HorizontalAlignment.Left);
listView1.Columns.Add("PORT", 50, HorizontalAlignment.Left);
listView1.Columns.Add("SERVER", 100, HorizontalAlignment.Left);
listView1.Columns.Add("TYPE", 100, HorizontalAlignment.Left);
listView1.Columns.Add("COMMENT", 100, HorizontalAlignment.Left);
}
private void button1_Click(object sender, EventArgs e)
{
AddItem();
}
我真正挣扎的是理解如何将每个函数转换为返回值，并在调用后可以在后台使用。
无论我尝试什么，它都会丢失一些东西。 您能使我更清楚吗？ 这样做只是扫描本地网络以找到其他PC上的Web服务器的当前IP。
但是255 ips需要花费一些时间，而应用程序却挂起了，不得不等到完成为止？
已应用答案代码：
public async void AddItem()
{
//listView1.Items.Clear();
int froms192 = Convert.ToInt32(tB1.Text);
int froms168 = Convert.ToInt32(tB2.Text);
int froms1a = Convert.ToInt32(tB3.Text);
int froms1b = Convert.ToInt32(tB4.Text);
int fromports = Convert.ToInt32(tBp1.Text);
int toports = Convert.ToInt32(tBp2.Text);
string FromIP = froms192 + "." + froms168 + "." + froms1a + "." + froms1b;
int FromPort = fromports;
int ToPort = toports;
int tos192 = Convert.ToInt32(tB5.Text);
int tos168 = Convert.ToInt32(tB6.Text);
int tos1a = Convert.ToInt32(tB7.Text);
int tos1b = Convert.ToInt32(tB8.Text);
string ToIP = froms192 + "." + froms168 + "." + froms1a + "." + froms1b;
if (froms1a < tos1a || froms1b < tos1b)
{
//var listViewItems = new List<ListViewItem>();
await Task.Run(() =>
{
for (int i = froms1b; i <= tos1b; i++)
{
List<string[]> rows = new List<string[]>();
for (int u = froms1a; u <= tos1a; u++)
{
for (int p = fromports; p <= toports; p++)
{
string GenIP = froms192 + "." + froms168 + "." + u + "." + i;
string result = GetProxyType(GenIP, p);
if (result != "")
{
string[] row = { Convert.ToString(GenIP), Convert.ToString(fromports), Convert.ToString(result), Convert.ToString(tos1a), Convert.ToString(tos1a) };
var listViewItem = new ListViewItem(row);
if (listView1.InvokeRequired)
{
listView1.Invoke(new MethodInvoker(delegate
{
listView1.Items.Add(listViewItem);
//row.Checked = true;
}));
}
else
{
listView1.Items.Add(listViewItem);
listViewItem.Checked = true;
}
//string[] row = { Convert.ToString(GenIP), Convert.ToString(fromports), Convert.ToString(result), Convert.ToString(tos1a), Convert.ToString(tos1a) };
//listViewItems.Add(row);
//listView1.Items.AddRange(rows.Select(a => new ListViewItem(a)).ToArray());
};
}
}
}
});
}
}
private async void button1_Click(object sender, EventArgs e)
{
AddItem();
}
答案 0 :(得分：1)
您将在需要异步运行的任何方法上使用async关键字。您在要在后台运行的代码上使用await。等待将控制权交还给UI，直到该代码完成。您仅对具有await的方法使用async，并且仅对返回Task的代码使用await。如果您有需要在后台运行的代码并且它没有返回Task，则可以将其包装在Task.Run中。
我认为这会起作用，但是我尚未对其进行测试。
public WebpageLocalScanner()
{
InitializeComponent();
InitializeListView();
}
internal string GetType(string ip, int port)
{
try
{
if (port == 1234 || port == 4321)
{
string urlAddress = string.Format("http://{0}", ip);
string text = this.GetHttpData(ip, 80, urlAddress, 5120).ToUpper();
if (text.Contains("<HTML>"))
{
return "Webpage is here";
}
}
}
catch (Exception)
{
}
return string.Empty;
}
public async void AddItem() {
listView1.Items.Clear();
int froms192 = Convert.ToInt32(tB1.Text);
int froms168 = Convert.ToInt32(tB2.Text);
int froms1a = Convert.ToInt32(tB3.Text);
int froms1b = Convert.ToInt32(tB4.Text);
int fromports = Convert.ToInt32(tBp1.Text);
int toports = Convert.ToInt32(tBp2.Text);
string FromIP = froms192 + "." + froms168 + "." + froms1a + "." + froms1b;
int FromPort = fromports;
int ToPort = toports;
int tos192 = Convert.ToInt32(tB5.Text);
int tos168 = Convert.ToInt32(tB6.Text);
int tos1a = Convert.ToInt32(tB7.Text);
int tos1b = Convert.ToInt32(tB8.Text);
string ToIP = froms192 + "." + froms168 + "." + froms1a + "." + froms1b;
if (froms1a < tos1a || froms1b < tos1b)
{
var rows = new List<string[]>();
await Task.Run(() => {
for (int i = froms1b; i <= tos1b; i++)
{
for (int u = froms1a; u <= tos1a; u++)
{
for (int p = fromports; p <= toports; p++)
{
string GenIP = froms192 + "." + froms168 + "." + u + "." + i;
string result = GetType(GenIP, p);
if (result != null) {
string[] row = { Convert.ToString(GenIP), Convert.ToString(fromports), Convert.ToString(result), Convert.ToString(tos1a), Convert.ToString(tos1a) };
rows.add(row);
};
}
}
}
});
listView1.Items.AddRange(rows.Select(a => new ListViewItem(a)).ToArray());
}
}
private void InitializeListView()
{
// Set the view to show details.
listView1.View = View.Details;
// Allow the user to edit item text.
listView1.LabelEdit = true;
// Allow the user to rearrange columns.
listView1.AllowColumnReorder = true;
// Display check boxes.
// listView1.CheckBoxes = true;
// Select the item and subitems when selection is made.
listView1.FullRowSelect = true;
// Display grid lines.
listView1.GridLines = true;
// Sort the items in the list in ascending order.
listView1.Sorting = SortOrder.Ascending;
// Attach Subitems to the ListView
listView1.Columns.Add("IP", 100, HorizontalAlignment.Left);
listView1.Columns.Add("PORT", 50, HorizontalAlignment.Left);
listView1.Columns.Add("SERVER", 100, HorizontalAlignment.Left);
listView1.Columns.Add("TYPE", 100, HorizontalAlignment.Left);
listView1.Columns.Add("COMMENT", 100, HorizontalAlignment.Left);
}
private async void button1_Click(object sender, EventArgs e)
{
AddItem();
}