背景工作的问题 [英] problem with background work
本文介绍了背景工作的问题的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
public string HttpGet(string URI)
{
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(URI);
req.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
req.Accept = "*/*";
req.Headers.Add("UA-CPU", "x86");
req.Headers.Add("Accept-Language", "en-us");
req.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322)";
HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
//Read all headers from the response & Request
WebHeaderCollection ResponseHeader = resp.Headers;
WebHeaderCollection RequestHeader = req.Headers;
StreamReader sr = new StreamReader(resp.GetResponseStream());
string s = URI;
string s1 = req.RequestUri + " / " + (int)resp.StatusCode + " / " + resp.StatusDescription + Environment.NewLine + ResponseHeader.ToString() + sr.ReadToEnd();
string s2 = req.RequestUri + " /" + req.Method + " / " + req.ProtocolVersion + " / " + Environment.NewLine + RequestHeader.ToString();
NetworkMonitor(s, s1, s2);
return s1.Trim();
}
private void bw_DoWork(object sender, DoWorkEventArgs e)
{
// startextraction();
BackgroundWorker worker = (BackgroundWorker)sender;
try
{
using (StreamReader reader = new StreamReader("F://testing.txt"))
{
int out_count = 0;
int out_count_1 = 0;
int out_count_2 = 0;
int row_count = 0;
DataTable table = new DataTable();
foreach (DataRow rw in table_1.Rows)
{
table.Columns.Add(rw[0].ToString());
}
string input;
int i = 0;
while ((input = reader.ReadLine()) != null)
{
string sourcecode = HttpGet(input);
worker.ReportProgress(i);
//string sourcecode = HttpPost(input, PostRaw);
//run_logs.AppendText("[Traversed] " + input + DateTime.Now.ToString());
//run_logs.AppendText(Environment.NewLine);
//run_logs.Update();
// Here we check the Match instance.
foreach (DataRow row in table_1.Rows)
{
int index = table_1.Rows.IndexOf(row);
//Here we call Regex.Match.
Match match = Regex.Match(sourcecode, row[1].ToString(), RegexOptions.IgnoreCase);
int count = 0;
while (match.Success)
{
// Finally, we get the Group value and display it.
if (index == 0)
{
table.Rows.Add(match.Groups[Convert.ToInt32(row[2].ToString())].Value);
row_count++;
}
else if (index == 1)
{
try
{
table.Rows[out_count][index] = match.Groups[Convert.ToInt32(row[2].ToString())].Value;
}
catch
{
table.Rows.Add();
}
finally
{
table.Rows[out_count][index] = match.Groups[Convert.ToInt32(row[2].ToString())].Value;
}
out_count++;
}
else if (index == 2)
{
try
{
table.Rows[out_count_1][index] = match.Groups[Convert.ToInt32(row[2].ToString())].Value;
}
catch
{
table.Rows.Add();
}
finally
{
table.Rows[out_count_1][index] = match.Groups[Convert.ToInt32(row[2].ToString())].Value;
}
out_count_1++;
}
else if (index == 3)
{
try
{
table.Rows[out_count_2][index] = match.Groups[Convert.ToInt32(row[2].ToString())].Value;
}
catch
{
table.Rows.Add();
}
finally
{
table.Rows[out_count_2][index] = match.Groups[Convert.ToInt32(row[2].ToString())].Value;
}
out_count_2++;
}
else
{
}
count++;
match = match.NextMatch();
}
// run_logs.AppendText("[REGEX] " + regex + " Extracted " + count + " Matches");
// run_logs.AppendText(Environment.NewLine);
}
//toolStripProgressBar1.Maximum = 4;
//toolStripProgressBar1.Value = toolStripProgressBar1.Value + 1;
// run_logs.Update();
dataGridView1.DataSource = table;
dataGridView1.Update();
dataGridView1.FirstDisplayedScrollingRowIndex = row_count;
}
}
}
catch (Exception hg)
{
MessageBox.Show(hg.Message);
}
}
推荐答案
引用：
问题是跨线程操作无效：控制'dataGridView1'从其创建的线程以外的线程访问
the problem is Cross-thread operation not valid: Control 'dataGridView1' accessed from a thread other than the thread it was created on
这是一个众所周知的问题，你可能会找到很多信息只需谷歌搜索。更多， Microsoft 轻轻地提供解决它的指导方针：如何：对Windows窗体控件进行线程安全调用 [ ^ ]。
This is a well-know problem, you may find a lot of info just Googling for. Morevover, Microsoft gently provides the guidelines for solving it: How to: Make Thread-Safe Calls to Windows Forms Controls[^].
将结果分配给e.result并更新UI RunWorkerCompleted。
private void backgroundWorker1_DoWork（object sender，
DoWorkEventArgs e）
{
//您的密码
。
。
。
。
//将结果DataTable表分配给_DoWork
//中的e.Result到DoWorkEventArgs的Result属性
//对象。这将是
// RunWorkerCompleted事件处理程序。
e.Result = table;
}
//这个事件处理程序处理
//后台操作的结果。
private void backgroundWorker1_RunWorkerCompleted（
对象发件人，RunWorkerCompletedEventArgs e）
{
//首先，处理案例抛出异常的地方。
如果（e.Error！= null）
{
//处理错误
MessageBox.Show（ e.Error.Message）;
}
else if（e.Cancelled）
{
//接下来，处理用户取消
//操作的情况。
//请注意，由于在
// DoWork事件处理程序中的竞争条件，可能没有取消
//标记设置，即使
//已经调用CancelAsync。
}
else
{
//最后，处理操作
//成功的情况。
DataTable table =（DataTable）e.Result;
dataGridView1.DataSource = table;
dataGridView1.Update（）;
dataGridView1.FirstDisplayedScrollingRowIndex = table.Rows.Count;
}
}
Assign the result to e.result and update the UI in RunWorkerCompleted.
private void backgroundWorker1_DoWork(object sender,
DoWorkEventArgs e)
{
//Your code
.
.
.
.
// Assign the result DataTable table to e.Result in _DoWork
// to the Result property of the DoWorkEventArgs
// object. This is will be available to the
// RunWorkerCompleted eventhandler.
e.Result = table;
}
// This event handler deals with the results of the
// background operation.
private void backgroundWorker1_RunWorkerCompleted(
object sender, RunWorkerCompletedEventArgs e)
{
// First, handle the case where an exception was thrown.
if (e.Error != null)
{
// Handle Error
MessageBox.Show(e.Error.Message);
}
else if (e.Cancelled)
{
// Next, handle the case where the user canceled
// the operation.
// Note that due to a race condition in
// the DoWork event handler, the Cancelled
// flag may not have been set, even though
// CancelAsync was called.
}
else
{
// Finally, handle the case where the operation
// succeeded.
DataTable table= (DataTable) e.Result;
dataGridView1.DataSource = table;
dataGridView1.Update();
dataGridView1.FirstDisplayedScrollingRowIndex = table.Rows.Count;
}
}
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