我试图在 C# 中围绕线程进行思考,但我在实现此行为时遇到困难。
我需要一个简单的是/否对话框,当经过 30 秒时返回DialogResult.No
。
到目前为止,我得到的是:
Thread th = new Thread(() =>
{
try
{
result = message.ShowDialog();
}
catch (Exception)
{
}
});
th.Start();
Thread.Sleep(30000);
th.Abort();
当我在对话框中选择"是"或"否"时,它仍然等待 30 秒,我需要线程在收到响应时停止。
这可能是一个不费吹灰之力的事情,但我对 C# 相对较新,并且确实可以在这方面使用一些帮助。
您可以在初始化表单时使用计时器。计时器过期后,关闭表单。
Timer time1 = new Timer();
time1.Elapsed += new ElapsedEventHandler(OnTimedEvent);
time1.Interval = 30000; // 30 secs
...
time1.Enabled = true; // Start the timer
message.ShowDialog();
private void OnTimedEvent(object source, ElapsedEventArgs e)
{
// Close your Form
message.Close();
// Maybe you could set a variable, that indicates you, that the timer timed out
}
你必须覆盖ShowDialog()
并ShowDialog(owner)
。当调用显示对话框时,您启动一个计时器并转发到base.ShowDialog()
。当计时器引发tick事件时,只需调用Close()
即可。
下面是一个示例实现:
public partial class FormTimed : Form
{
private String _OriginalText;
private DateTime _StartTime;
private Timer _Timer;
public FormTimed()
{
InitializeComponent();
InitializeTimer();
Duration = TimeSpan.FromSeconds(10);
}
[DefaultValue(typeof(TimeSpan), "00:00:10")]
public TimeSpan Duration { get; set; }
public override string Text
{
get
{
return _OriginalText;
}
set
{
_OriginalText = value;
base.Text = value;
}
}
public void DisableTimer()
{
_Timer.Stop();
base.Text = _OriginalText;
}
public void ResetTimer()
{
_StartTime = DateTime.UtcNow;
_Timer.Start();
}
public new DialogResult ShowDialog()
{
StartTimer();
return base.ShowDialog();
}
public new DialogResult ShowDialog(IWin32Window owner)
{
StartTimer();
return base.ShowDialog(owner);
}
private void InitializeTimer()
{
_Timer = new Timer();
_Timer.Interval = 100;
_Timer.Tick += OnTimerTick;
}
private void OnTimerTick(object sender, EventArgs e)
{
var finishTime = _StartTime + Duration;
var remainingDuration = finishTime - DateTime.UtcNow;
if (remainingDuration < TimeSpan.Zero)
{
Close();
}
base.Text = _OriginalText + " (" + (int)remainingDuration.TotalSeconds + ")";
}
private void StartTimer()
{
_StartTime = DateTime.UtcNow;
_Timer.Start();
}
}