c#仲引用数组里面的元素

foreach(string s in dayofmin )
{
if(textbox1.text==s)
{
....
}
}

给TextBox注册TextChanged事件:
this.textBox1.TextChanged += new System.EventHandler (this.textBox1_TextChanged);

在窗体里写事件代码：
private void textBox1_TextChanged(object sender, EventArgs e)
{
string[] dayofmin ={ "4", "6", "9", "11" };
TextBox t = (TextBox)sender;
string text = t.Text;
foreach (string s in dayofmin)
{
if (text == s)
{

}
}
}