我运行一个进程,在命令行中使用参数执行exe,并且需要一些时间才能完成.在此期间,我将表单显示为带有进度条和取消按钮的对话框.按下取消按钮时,该过程应该中止/停止.我有两种方法可以做到：
A.在主窗体中声明Process类的公共静态对象,并在单击取消按钮时从进度窗体中止它：
public partial class frmMain : Form
{
public static Process Process = new Process();
public static bool ExecuteCommand(string sCommandLineFile,string sArguments)
{
Process.StartInfo.FileName = sCommandLineFile;
Process.StartInfo.Arguments = sArguments;
Process.StartInfo.CreateNoWindow = true;
Process.StartInfo.UseShellExecute = false;
Process.StartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
Process.Start();
Process.WaitForExit();
}
}
从Progress窗口表单中关闭/中止进程：
public partial class frmProgress : Form
{
private void btnCancel_Click(object sender,EventArgs e)
{
frmMain.Process.Close();
frmMain.Process.Dispose();
}
}
B.或者不要调用Process.WaitForExit();而是使用Process.HasExited来检查进程是否正在运行,如果单击取消按钮则取消它：
public static bool IsCancelled = false;
Process.StartInfo.FileName = sCommandLineFile;
Process.StartInfo.Arguments = sArguments;
Process.StartInfo.CreateNoWindow = true;
Process.StartInfo.UseShellExecute = false;
Process.StartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
while (!Process.HasExited)
{
Thread.Sleep(100);
Application.DoEvents();
if (IsCancelled)
{
Process.Close();
Process.Dispose();
}
}
public partial class frmProgress : Form
{
private void btnCancel_Click(object sender,EventArgs e)
{
frmMain.IsCancelled = true;
}
}
做正确的方法是什么？
解决方法
两者的混合.
public partial class frmMain : Form
{
public static Process Process = new Process();
public static bool ExecuteCommand(string sCommandLineFile,string sArguments)
{
Process.StartInfo.FileName = sCommandLineFile;
Process.StartInfo.Arguments = sArguments;
Process.StartInfo.CreateNoWindow = true;
Process.StartInfo.UseShellExecute = false;
Process.StartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
Process.Start();
// Process.WaitForExit(); // Don't wait here,you want the application to be responsive
}
}
并在取消处理程序中
private void btnCancel_Click(object sender,EventArgs e)
{
frmMain.Process.Close(); // or .Kill()
frmMain.Process.Dispose();
}
当然,现在您需要一种方法来查找过程是否已退出正常方式.定期使用Process.HasExit轮询终止.最好使用计时器.我目前还不确定,但可能会发生这样的事件.
您的第二个解决方案存在的问题是,它仍在主动等待进程完成,同时仍然阻止用户界面.它正在使用Application.DoEvents(),你应该避免它,因为它会产生各种令人讨厌的副作用(例如,你可以在递归中运行多次相同的代码).
