关于写入文件问题
我有2个textbox,1个用来显示文件的内容,另一个用于修改,程序如下
<%@ Page Language= "C# " AutoEventWireup= "true " CodeFile= "HtmlTo.aspx.cs " Inherits= "HtmlTo " validateRequest= "false " %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN " "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">
<html xmlns= "http://www.w3.org/1999/xhtml " >
<head runat= "server ">
<title> 无标题页 </title>
</head>
<body>
<form id= "form1 " runat= "server ">
<div>
<asp:DropDownList ID= "DropDownList1 " runat= "server " AutoPostBack= "True ">
<asp:ListItem Value= "1.html "> 计算机科学与技术 </asp:ListItem>
<asp:ListItem Value= "2.html "> 生物工程 </asp:ListItem>
<asp:ListItem Value= "3.html "> 国际经济与贸易 </asp:ListItem>
<asp:ListItem Value= "4.html "> 园林 </asp:ListItem>
</asp:DropDownList> <br />
<br />
<asp:TextBox ID= "TextBox1 " runat= "server " Height= "480px " TextMode= "MultiLine " Width= "386px "> </asp:TextBox> <br />
<asp:TextBox ID= "TextBox2 " runat= "server "> </asp:TextBox> <br />
<br />
<asp:Button ID= "Button1 " runat= "server " Text= "确定 " OnClick= "Button1_Click " /> </div>
</form>
</body>
</html>
---------------------
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.IO;
public partial class HtmlTo : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string filename;
filename = DropDownList1.SelectedValue;
StreamReader sr = new StreamReader(Server.MapPath( " ") + "\\ " + filename, System.Text.Encoding.GetEncoding( "GB2312 "));
TextBox1.Text = sr.ReadToEnd();
sr.Close();
//释放资源
sr.Dispose();
}
protected void Button1_Click(object sender, EventArgs e)
{
File.WriteAllText(Server.MapPath( " ") + "\\ " + "1.html ", TextBox2.Text, System.Text.Encoding.GetEncoding( "GB2312 "));
}
}
但是我每次都得点2下 "确定 ",才能修改成功,请问是什么原因
[解决办法]
其实你点击头一次的时候就已经修改成功了，只不过你看一下你的页面逻辑，点确定的时候会首先执行Page_Load，它会把还未修改的内容次读取到TextBox1里，然后再执行Button1_Click修改内容，当你再一次点击的时候，就会把修改后的内容读取到TextBox1里，你看着好像是点两次才能修改成功。
简单修改一下，没有测试不知道行不行，大概就是这个意思
protected void Page_Load(object sender, EventArgs e)
{
if(!isPostBack) FillText();
}
protected void FillText()
{
string filename;
filename = DropDownList1.SelectedValue;
StreamReader sr = new StreamReader(Server.MapPath( " ") + "\\ " + filename, System.Text.Encoding.GetEncoding( "GB2312 "));
TextBox1.Text = sr.ReadToEnd();
sr.Close();
//释放资源
sr.Dispose();
}
protected void Button1_Click(object sender, EventArgs e)
{
File.WriteAllText(Server.MapPath( " ") + "\\ " + "1.html ", TextBox2.Text, System.Text.Encoding.GetEncoding( "GB2312 "));
FillText();
}
[解决办法]
Button1_Click在Page_Load之后执行，第一次提交时其实1.html已经被修改了，只是TextBox1中读取的是未修改的内容，应该把设置TextBox1内容的代码放在Button1_Click之后，比如：OnPreRender中