if (MessageBox.Show("Please confirm before proceed" + "\n" + "Do you want to Continue ?", "Confirm", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)

{
//do something if YES
}

else

{
//do something if NO
}

@Mikael Svenson的答案是正确的。我只是想补充一点:

消息框图标还可以包含一个额外的属性，如下所示:

DialogResult dialogResult = MessageBox.Show("Sure", "Please Confirm Your Action", MessageBoxButtons.YesNo, MessageBoxIcon.Question);

MessageBox确实会产生一个dialgresults

DialogResult r = MessageBox.Show("Some question here");

您还可以很容易地指定按钮。更多文档可以在http://msdn.microsoft.com/en-us/library/ba2a6d06.aspx上找到

试试这个:

if (MessageBox.Show("Are you sure", "Title_here", MessageBoxButton.YesNo) == MessageBoxResult.Yes)
{
    Do something here for 'Yes'...
}

DialogResult dr = MessageBox.Show("Are you happy now?", 
                      "Mood Test", MessageBoxButtons.YesNo);
switch(dr)
{
   case DialogResult.Yes:
      break;
   case DialogResult.No:
      break;
}

MessageBox类就是您要找的。

这应该做到:

DialogResult dialogResult = MessageBox.Show("Sure", "Some Title", MessageBoxButtons.YesNo);
if(dialogResult == DialogResult.Yes)
{
    //do something
}
else if (dialogResult == DialogResult.No)
{
    //do something else
}