暂停和在C＃中恢复一个for循环

本文介绍了暂停和在C＃中恢复一个for循环的处理方法，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

我工作的一个Windows应用程序在C＃中，我有一个循环for循环哪个更新的东西，我有一个名为停止，暂停，恢复表单上的3个按键。因此，其目的是为命名的按钮相同。有谁知道如何做到这一点？

下面是循环

私人无效btnCompleteAuto_Click（对象发件人，EventArgs五） { setGeneralValue（）; 的for（int i = 1; I< = autoGridView.Rows.Count - 1;我++） {如果（SRP ==暂停）//这是我思维，但它不会工作， {//将步入年底少环做//如何制止这一循环恢复按钮，点击 { }，而（SRP =恢复！） } 车= FALSE; 试 { MEMBERID = Convert.ToInt64（autoGridView.Rows [0] .Cells [Member_ID]值。）; DISPID = Convert.ToString（autoGridView.Rows [0] .Cells [Disp_Id]值。）; =移动Convert.ToString（autoGridView.Rows [0] .Cells [手机]值。）; DUEDATE = Convert.ToString（autoGridView.Rows [0] .Cells [DUE_DATE]值。）; } 赶上（例外） { MessageBox.Show（未找到行）; } AutoRecharge（网络名，pack_name，手机，移动，Convert.ToString（autoGridView.Rows [0] .Cells [Rck_Amt]。值），VENDOR_ID，vendor_pwd，pack_id， oxinetwork_id）; autoGridView.Rows.RemoveAt（0）; } }

下面是在我的3按钮事件设置变量

私人无效btnPause_Click（对象发件人，EventArgs五） { SRP =暂停 } 私人无效btnStop_Click（对象发件人，EventArgs五） { SRP =停止; autoGridView.DataSource =; } 私人无效btnResume_Click（对象发件人，EventArgs五） { SRP =恢复; }

解决方案

究其原因，这并不如你期望的工作是这样的：

一个Windows窗体应用程序使用的单的UI线程，不断地从队列处理传入的消息。您连接到一个Windows窗体的事件的任何事件处理程序控件得到迅速发送到此队列和处理UI线程越好。

您 btnCompleteAuto_Click 就是这样的一个处理程序。一旦开始，不出意外将被UI线程直到它退出的处理。因此，任何的其他的附加到处理程序的其他的事件（ btnPause_Click ， btnStop_Click 等），必须等待轮到他们，因为他们将在相同的（UI）线程上运行。

如果你想暂停/恢复功能，这有的上一个单独的线程来实现。

要实现它可能会使用的BackgroundWorker ，因为由SAURABH 。

下面是一个粗糙的的更新的代码可能是什么样子（我还没有尝试素描的编译此，更不用说调试它;它的目的只是为如何完成这个功能），一个基本的轮廓。

您需要注意，但是，访问UI控件直接从非UI线程是一个没有没有。使用一种机制，如 BackgroundWorker.ProgressChanged 事件来处理，你需要根据一个非UI线程活动发生任何UI更新。

ManualResetEvent的_busy =新的ManualResetEvent（假）; 私人无效btnCompleteAuto_Click（对象发件人，EventArgs五） {如果 { _busy.Set（）（backgroundWorker.IsBusy！）; btnAutoCompleteAuto.Text =暂停; backgroundWorker.RunWorkerAsync（）; } ，否则 { _busy.Reset（）; btnAutoCompleteAuto.Text =恢复; } btnStop.Enabled = TRUE; } 私人无效btnStop_Click（对象发件人，EventArgs五） { _busy.Set（）; backgroundWorker.CancelAsync（）; } 私人无效backgroundWorker_DoWork（对象发件人，DoWorkEventArgs E） { //（某事） // { _busy.WaitOne（）; 如果（backgroundWorker.CancellationPending） {的回报; } //在这里做你的工作。 //} } 私人无效backgroundWorker_RunWorkerCompleted（对象发件人，RunWorkerCompletedEventArgs E） { _busy.Reset（）; btnAutoCompleteAuto.Text =开始; btnStop.Enabled = FALSE; }

I'm working on a windows App in C#, I have a for-loop which update something in a loop, and I have 3 buttons on the form named "Stop,Pause,Resume". So the purpose is as same as the buttons named. Does anyone know how to do this?

Here is the Loop

private void btnCompleteAuto_Click(object sender, EventArgs e) { setGeneralValue(); for (int i = 1; i <= autoGridView.Rows.Count - 1; i++) { if (SRP == "Pause") // this is what I was thinking but it won't work { // it will step into end-less loop do // how to stop this loop on "Resume" button click { }while(SRP!="Resume") } car = false; try { MemberID = Convert.ToInt64(autoGridView.Rows[0].Cells["Member_ID"].Value); DispID = Convert.ToString(autoGridView.Rows[0].Cells["Disp_Id"].Value); Mobile = Convert.ToString(autoGridView.Rows[0].Cells["Mobile"].Value); DueDate = Convert.ToString(autoGridView.Rows[0].Cells["Due_Date"].Value); } catch (Exception) { MessageBox.Show("Row Not Found"); } AutoRecharge(network_name, pack_name, Mobile, Mobile, Convert.ToString(autoGridView.Rows[0].Cells["Rck_Amt"].Value), vendor_id, vendor_pwd, pack_id, oxinetwork_id); autoGridView.Rows.RemoveAt(0); } }

Here are the 3 button events in which I'm setting a variable

private void btnPause_Click(object sender, EventArgs e) { SRP = "Pause"; } private void btnStop_Click(object sender, EventArgs e) { SRP = "Stop"; autoGridView.DataSource = ""; } private void btnResume_Click(object sender, EventArgs e) { SRP = "Resume"; }

解决方案

The reason this doesn't work as you expect is this:

A Windows Forms application uses a single UI thread, which continually processes incoming messages from a queue. Any event handlers you attach to the events of a Windows Forms control get sent to this queue and processed by the UI thread as quickly as possible.

Your btnCompleteAuto_Click is one such handler. Once it starts, nothing else will be processed by the UI thread until it exits. Thus any other handlers you attach to other events (btnPause_Click, btnStop_Click, etc.) must wait their turn, as they will run on the same (UI) thread.

If you want pause/resume functionality, this has to be achieved on a separate thread.

A possible way to implement it might be to use a BackgroundWorker, as suggested by saurabh.

Here is a rough sketch of what your updated code might look like (I have not even attempted to compile this, let alone debug it; it's intended only as a basic outline of how you might accomplish this functionality).

You need to be aware, however, that accessing UI controls directly from a non-UI thread is a no-no. Use a mechanism such as the BackgroundWorker.ProgressChanged event to handle any UI updates that you need to happen based on activity on a non-UI thread.

ManualResetEvent _busy = new ManualResetEvent(false); private void btnCompleteAuto_Click(object sender, EventArgs e) { if (!backgroundWorker.IsBusy) { _busy.Set(); btnAutoCompleteAuto.Text = "Pause"; backgroundWorker.RunWorkerAsync(); } else { _busy.Reset(); btnAutoCompleteAuto.Text = "Resume"; } btnStop.Enabled = true; } private void btnStop_Click(object sender, EventArgs e) { _busy.Set(); backgroundWorker.CancelAsync(); } private void backgroundWorker_DoWork(object sender, DoWorkEventArgs e) { // for (something) // { _busy.WaitOne(); if (backgroundWorker.CancellationPending) { return; } // Do your work here. // } } private void backgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) { _busy.Reset(); btnAutoCompleteAuto.Text = "Start"; btnStop.Enabled = false; }