延时并自动关闭MessageBox

信息提示框（MessageBox）是微软NET自带的一个用于弹出警告、错误或者讯息一类的“模式”对话框。此类对话框一旦开启，则后台窗体无法再被激活（除非当前的MessageBox被点击或者关闭取消）。那么如何使用程序模拟鼠标点击这个messageBox（关闭这个MessageBox）呢？答案是你在弹出这个messageBox之前先启用一个定时器，定时器内部不断向窗体发送Enter按钮用于模拟点击MsgBox的内容，同时主程序中弹出模式消息框。代码如下（VS2012 RC 编写）：

我们假设窗体上就一个Button，点击这个Button将弹出5个msgbox，同时每个msgbox将延时2秒后自动关闭。

[C#]

public partial class Form1 : Form
{
private System.Windows.Forms.Timer[] ts = new System.Windows.Forms.Timer[6];

public Form1()
{
InitializeComponent();

}

void t_Tick(object sender, EventArgs e)
{
((System.Windows.Forms.Timer)sender).Enabled = false;
SendKeys.SendWait("{Enter}");
}

private void button1_Click(object sender, EventArgs e)
{
Action act = new Action(() =>
{
for (int i = 0; i < 6; i++)
{
ts[i] = new System.Windows.Forms.Timer();
ts[i].Tick += t_Tick;
ts[i].Interval = 2000;
ts[i].Enabled = true;
MessageBox.Show("MsgBox" + (i + 1));
Thread.Sleep(2000);
}
});
act.BeginInvoke(null, null);
}

}

[VB.NET]

Public Partial Class Form1
Inherits Form
Private ts As System.Windows.Forms.Timer() = New System.Windows.Forms.Timer(5) {}

Public Sub New()

InitializeComponent()
End Sub

Private Sub t_Tick(sender As Object, e As EventArgs)
DirectCast(sender, System.Windows.Forms.Timer).Enabled = False
SendKeys.SendWait("{Enter}")
End Sub

Private Sub button1_Click(sender As Object, e As EventArgs)
Dim act As New Action(Sub()
For i As Integer = 0 To 5
ts(i) = New System.Windows.Forms.Timer()
AddHandler ts(i).Tick, AddressOf t_Tick
ts(i).Interval = 2000
ts(i).Enabled = True
MessageBox.Show("MsgBox" & (i + 1))
Thread.Sleep(2000)
Next
End sub)
act.BeginInvoke(Nothing, Nothing)
End Sub

End Class

注意1：这里使用了“委托异步”是为了防止主线程被Thread延时导致假死的情况发生。

注意2：SendKeys这里必须使用SendWait，否则会抛出异常。