Form.ShowDialog()方法会导致代码停止执行，直到新调用的窗体关闭为止。我需要在调用ShowDialog()方法后让代码继续运行。我搜索并阅读了使用BackgroundWorker的相关信息，但这是我第一次听说它，以前从未使用过。
Form2 form2this = new Form2();
form2this.ShowDialog();
MessageBox.Show("Something");
点击按钮后会执行这段代码，我要如何调用 ShowDialog 方法以防止用户与主窗体交互，但仍允许主窗体继续工作？
如果已经有讨论此问题的内容，那么请见谅，但我发现所有的方法都过于复杂，而这个任务本身却很简单。实际上，我很惊讶 ShowDialog 方法中没有包含这种功能，例如 ShowDialog().Continue 就很好。
如果您只是想让代码继续执行而不会阻塞直到弹出窗口关闭，请考虑使用Show而不是ShowDialog。
如果您希望在子窗体弹出时父窗体执行一些操作，那么使用BackgroundWorker(或启动一个新的Thread/Task)可能是合适的。不过更多了解这些任务的信息会有所帮助。如果需要与主窗体或子窗体交互，那么这似乎会有麻烦; 只需要进行一些后台任务而没有UI交互，那么这就是正确的思路。
另一个可能性是，您真正想做的事情实际上应该在子窗体中完成，而不是在父窗体中。
BackgroundWorker 或 Task 来执行长时间运行的任务，然后在启动后使用 ShowDialog 显示对话框窗体。 - Servyprivate async void button1_Click(object sender, EventArgs e)
{
// create and display modal form
Form2 modalForm = new Form2();
BeginInvoke((Action)(() => modalForm.ShowDialog()));
// do your async background operation
await DoSomethingAsync();
// close the modal form
modalForm.Close();
}
private async Task DoSomethingAsync()
{
// example of some async operation....could be anything
await Task.Delay(10000);
}
这是我的方式，很丑陋但我没有更好的想法。
private void AppUiMain_Shown(object sender, EventArgs e)
{
var loading = new AppUiLoading();
loading.Shown += (o, args) =>
{
bool isLoading = true;
loading.Top = (int)(loading.Top * 1.16);
Application.DoEvents();//refresh ui
EventHandler ehr = null;
EventHandler ehe = null;
ehr = (ss, ee) =>
{
App.Instance.Ready -= ehr;
App.Instance.Error -= ehe;
isLoading = false;
};
ehe = (ss, ee) =>
{
loading.Text = "Error";
loading.ShowAbortButton("Error occur");
};
App.Instance.Error += ehe;
App.Instance.Ready += ehr;
InitApp();
//HACK: find a better way to `refresh' main form
Application.DoEvents();
this.Height++;
this.Height--;
//HACK: find a better way to keep message looping on ShowDialog
while (isLoading)
Application.DoEvents();
loading.Close();
};
loading.ShowDialog(this);
}
http://newapputil.blogspot.in/2015/05/continue-executing-code-after-calling.html
我认为下一个异步ShowDialog的解决方案是：
public bool DialogResultAsync
{
get;
private set;
}
public async Task<bool> ShowDialogAsync()
{
var cts = new CancellationTokenSource();
// Attach token cancellation on form closing.
Closed += (object sender, EventArgs e) =>
{
cts.Cancel();
};
Show(); // Show message without GUI freezing.
try
{
// await for user button click.
await Task.Delay(Timeout.Infinite, cts.Token);
}
catch (TaskCanceledException)
{ }
}
public void ButtonOkClick()
{
DialogResultAsync = true;
Close();
}
public void ButtonCancelClick()
{
DialogResultAsync = false;
Close();
}
在主窗体中，您必须使用此代码：
public async void ShowDialogAsyncSample()
{
var msg = new Message();
if (await msg.ShowDialogAsync())
{
// Now you can use DialogResultAsync as you need.
System.Diagnostics.Debug.Write(msg.DialogResultAsync);
}
}
运行异步调用以显示模态框。以下是wpf中的示例：
private Window waitView;
/// <summary>
/// Closes a displayed WaitView from code.
/// </summary>
public void CloseWaitView()
{
if(waitView != null)
{
// Work on the gui Thread of waitView.
waitView.Dispatcher.Invoke(new Action(() => close()));
}
}
/// <summary>
/// Closes a displayed WaitView and releases waitView-Instance.
/// </summary>
private void close()
{
waitView.Close();
waitView = null;
}
/// <summary>
/// Showes a modal WaitView (Window).
/// </summary>
public void ShowWaitView()
{
// instance a new WaitViewWindow --> your Window extends Window-Class
waitView = new WaitViewWindow();
// prepare a operation to call it async --> your ShowDialog-call
var asyncCall = new Action(() => waitView.Dispatcher.Invoke(
new Action(() => waitView.ShowDialog())
));
// call the operation async
// Argument 1 ar:
// ar means IAsyncResult (what should be done, when come back from ShowDialog -->
// remove view memory with set waitView to null or ... dispose
// the second argument is an custom parameter you can set to use in ar.AsyncState
asyncCall.BeginInvoke(ar => waitView = null, null);
// all from here is done during ShowDialog ...
}
Parentform.Enabled = false。 - Brad