[我的ASP.net学习历程]IsPostBack

<%@ page language="c#" autoeventwireup="true" %>
<script language="c#" runat="server">
void page_load(object sender,eventargs e){
 if (!ispostback){  //判断是否为第一次页面调入
  label_1.text="good!";
  }
 else{
  label_1.text="bad";
  }
}
void buttonclick(object sender,eventargs e){
 label_2.text="button is click!";
 }
</script>
<asp:label id="label_1" runat="server"></asp:label>
<form id="form_1" runat="server">
 <asp:button id="button_1" text="button" onclick="buttonclick" runat="server"/>
</form>
<asp:label id="label_2" runat="server"></asp:label>