[C#]using System.Text;
[VB]Imports System.Text
[C#]StringBuilder sbFirst = new StringBuilder();
sbFirst.Append(“这是第一个学ASPNET的例子</br>”);
sbFirst.Append( “这个例子太简单</br>”);
sbFirst.Append( “连三岁小陔都会做,我早知道了,嘿嘿。”);
Response.Write(sbFirst.ToString());
[VB]Dim sbFirst As StringBuilder = New StringBuilder()
sbFirst.Append(“这是第一个学ASPNET的例子</br>”)
sbFirst.Append( “这个例子太简单</br>”)
sbFirst.Append( “连三岁小陔都会做,我早知道了,嘿嘿。”)
Response.Write(sbFirst.ToString)
private void btnShowVariable_Click(object sender, System.EventArgs e)
{
labServerVariables.Text = "";
StringBuilder info = new StringBuilder();
foreach (object objVar in Request.ServerVariables)
{
info.Append("<span style="font-size:9pt">");
info.Append(objVar.ToString());
info.Append(" = <font color=blue>");
info.Append(Request.ServerVariables[objVar.ToString()]);
info.Append("</font></span><br>");
}
labServerVariables.Text = info.ToString();
}
Response.Write(Request.ServerVariables["REMOTE_ADDR"]); // IP地址
Response.Write("<BR>");
Response.Write(Request.ServerVariables["URL"]); // 网页的URL
第二天
学习目的:
private void btnCheck_Click(object sender, System.EventArgs e)
{
int year, month, date;
// 先把输入的字符转成int类型,如果非数字型,
// 会触发错误
try
{
year = Convert.ToInt32(txtYear.Text);
month = Convert.ToInt32(txtMonth.Text);
date = Convert.ToInt32(txtDate.Text);
}
catch
{
labCheckInfo.Text = "输入的是非数字字符。";
return;
}
// 如果第一步检验合格,就把输入的数字转化为日期格式
// 如果不符合日期格式即引发错误
try
{
DateTime dt = new DateTime(year, month, date);
}
catch
{
labCheckInfo.Text = "输入的数字不符合日期格式";
return;
}
labCheckInfo.Text = "输入正确";
}
嗯,补充一下,关于StringBuider
在处理字符串的时候很多人喜欢+=,其实对于string来说,一旦定义了就无法更改了
所谓的+只是新建的一个新的string变量并赋值
所以对于尽量使用StringBuider的Append的方法,这样将大量的节省服务器的资源
第三天
学习目的:
<asp:DropDownList id="dlstWeb" style="Z-INDEX: 101; LEFT: 32px;
POSITION: absolute; TOP: 32px" runat="server"
Width="88px" AutoPostBack="True">
<asp:ListItem value="http://www.sina.com.cn">新浪 </asp:ListItem>
<asp:ListItem value="http://www.sohu.com">搜狐</asp:ListItem>
<asp:ListItem value="http://www.163.com">网易</asp:ListItem>
</asp:DropDownList>
private void dlstWeb_SelectedIndexChanged(object sender, System.EventArgs e)
{
Response.Write("<script language=javascript>window.open("" +dlstWeb.Selectedvalue + "");</script>");
}
private void Page_Load(object sender, System.EventArgs e)
{
// 用IsPostBack判断,只在没有回传时才初始化
// 这样可以防止每次刷新或回传时,都执行一次以下代码
// 可以节省服务器的资源了。
if (!IsPostBack)
{
DataTable dt = new DataTable();
DataRow dr;
// 在表中增加字段
dt.Columns.Add("WebName", typeof(string));
dt.Columns.Add("WebUrl", typeof(string));
// 表中增加行
dr = dt.NewRow();
dr["WebName"] = "新浪";
dr["WebUrl"] = " http://www.sina.com.cn ";
dt.Rows.Add(dr);
dr = dt.NewRow();
dr["WebName"] = "网易";
dr["WebUrl"] = " http://www.163.com ";
dt.Rows.Add(dr);
dr = dt.NewRow();
dr["WebName"] = "搜狐";
dr["WebUrl"] = " http://www.sohu.com ";
dt.Rows.Add(dr);
// 把表与下拉菜单绑定数据
dlstWeb.DataSource = dt;
dlstWeb.DataTextField = "WebName";
dlstWeb.DatavalueField = "WebUrl";
dlstWeb.DataBind();
// 开始时就把下拉菜单的AutoPostBack设为false,
// 防止一开始就乱跳出网页来
dlstWeb.AutoPostBack = true;
}
}
private void dlstWeb_SelectedIndexChanged(object sender, System.EventArgs e)
{
Response.Write("<script language=javascript>window.open("" +dlstWeb.Selectedvalue + "");</script>");
}
VB.NET增加字段代码稍有不同,如下:
// 在表中增加字段
dt.Columns.Add("WebName", GetType(String))
dt.Columns.Add("WebUrl", GetType(String))
其它都差不多了。
每四天
学习目的:
<configuration>
<appSettings>
<add key="数据库1" value="ex01.mdb" />
</appSettings>
……
using System.Configuration;
using System.Data.OleDb;
using System.Text;
以下在Page的Load事件中,读取ACCESS数据库,并用表格显示出来: private void Page_Load(object sender, System.EventArgs e)
{
StringBuilder sbTable = new StringBuilder(); // 用于输出表格的语句
string strConnection = "Provider=Microsoft.Jet.Oledb.4.0;Data Source="
+ Server.MapPath(ConfigurationSettings.AppSettings["数据库1"]);
// 连接数据库的语句
OleDbConnection conn = new OleDbConnection(strConnection);
// 建立DbCommand对象
OleDbCommand cmd = conn.CreateCommand();
cmd.CommandText = "SELECT * FROM Book";
// 打开数据库
conn.Open();
// 用DataReader读取数据
OleDbDataReader dr = cmd.ExecuteReader();
sbTable.Append("<table cellSpacing="0" cellPadding="0" border="1"><tr>");
sbTable.Append("<td>书名</td><td>作者</td><td>单价<td></tr>");
while (dr.Read())
{
sbTable.Append("<tr><td>");
sbTable.Append(dr["BookTitle"].ToString());
sbTable.Append("</td><td>");
sbTable.Append(dr["Author"].ToString());
sbTable.Append("</td><td>");
sbTable.Append(dr["UnitPrice"].ToString());
sbTable.Append("</td><tr>");
}
sbTable.Append("</tr></table>");
// 记住dr用毕必须关闭,否则会阻塞服务器
dr.Close();
// DbConnection是受托管的,可以不关闭
// 但为良好的编程习惯,应该关闭
conn.Close();
Response.Write(sbTable.ToString());
}
显示结果 第五天
学习目的:
CREATE TABLE [dbo].[Member] (
[MemberID] [int] IDENTITY (1, 1) NOT NULL ,
[MemberName] [nvarchar] (50) COLLATE Chinese_PRC_CI_AS NOT NULL ,
[Password] [nvarchar] (50) COLLATE Chinese_PRC_CI_AS NOT NULL ,
[Gender] [bit] NOT NULL ,
[Birthday] [datetime] NULL ,
[Email] [nvarchar] (50) COLLATE Chinese_PRC_CI_AS NULL
) ON [PRIMARY]
ALTER TABLE [dbo].[Member] WITH NOCHECK ADD
CONSTRAINT [PK_Member] PRIMARY KEY CLUSTERED
(
[MemberID]
) ON [PRIMARY]
<appSettings>
<add key="数据库1" value="ex01.mdb" />
<add key="SqlDatabase1" value="data source=localhost;user id=sa;password=sa;initial catalog=AspNetABC;Connect Timeout=30" />
</appSettings>
private void btnLogin_Click(object sender, System.EventArgs e)
{
// 先检验输入正确性
if (txtMemberName.Text == String.Empty || txtMemberName.Text.Trim() == "")
{
Response.Write("<script language=javascript>alert("帐号不能为空")</script>");
return;
}
if (txtPassword.Text == String.Empty || txtPassword.Text.Trim() == "")
{
Response.Write("<script language=javascript>alert("没有输入密码")</script>");
return;
}
string strConnection = ConfigurationSettings.AppSettings["SqlDatabase1"];
string sqlMember = "SELECT MemberName ,[Password] FROM Member "
+ " WHERE MemberName = "" + txtMemberName.Text.Trim() + """
+ " AND [Password] = "" + txtPassword.Text.Trim() + """;
// 连接SqlServer数据库
SqlConnection conn = new SqlConnection(strConnection);
// 建立SqlCommand
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = sqlMember;
conn.Open();
// 建立DataReader
SqlDataReader dr = cmd.ExecuteReader();
// 判断DataReader是否为空记录
if (dr.HasRows)
{
Response.Write("<script language=javascript>alert("" + txtMemberName.Text + "欢迎你!")</script>");
}
else
{
Response.Write("<script language=javascript>alert("找不到该会员,或密码错误。")</script>");
}
// 千万不要忘记关闭DataReader
dr.Close();
conn.Close();
}
第六天
学习目的
CREATE TABLE [dbo].[NewsArticle] (
[NewsArticleID] [int] IDENTITY (1, 1) NOT NULL ,
[Title] [nvarchar] (50) COLLATE Chinese_PRC_CI_AS NOT NULL ,
[SubTitle] [nvarchar] (50) COLLATE Chinese_PRC_CI_AS NULL ,
[Content] [ntext] COLLATE Chinese_PRC_CI_AS NOT NULL ,
[Writer] [nvarchar] (10) COLLATE Chinese_PRC_CI_AS NULL ,
[PubTime] [datetime] NOT NULL
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
ALTER TABLE [dbo].[NewsArticle] WITH NOCHECK ADD
CONSTRAINT [DF_NewsArticle_PubTime] DEFAULT (getdate()) FOR [PubTime],
CONSTRAINT [PK_NewsArticle] PRIMARY KEY CLUSTERED
(
[NewsArticleID]
) ON [PRIMARY]
GO
private void btnPublish_ServerClick(object sender, System.EventArgs e)
{
string strConnection = ConfigurationSettings.AppSettings["SqlDatabase1"];
// 连接SqlServer数据库
SqlConnection conn = new SqlConnection(strConnection);
// 建立SqlCommand
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "INSERT INTO NewsArticle (Title, SubTitle, Writer, Content) valueS ("
+ """ + txtTitle.Text + "","
+ """ + txtSubTitle.Text + "","
+ """ + txtWriter.Text + "","
+ """ + txtContent.Text + "")";
conn.Open();
//Response.Write (cmd.CommandText);
// 插入记录
try
{
cmd.ExecuteNonQuery();
}
catch (Exception ex)
{
Response.Write("<script language=javascript>alert("输入错误,数据库不能更新。")</script>");
}
finally
{
conn.Close();
}
}
注意Command对象的ExecuteNonQuery()方法使用,该方法可以用于插入、更新、删除等操作,是Command对象的重要方法。今天介绍了Command语句的最基本用法,下次还将介绍占位符的用法。好了,各位先消化一下,明后天将做实用的东东了。 第七天
学习目的
txtTitle:MaxLength(50);
txtSubTitle: MaxLength(50);
txtWriter: MaxLength(10);
这样可以防止输入过长字符串
rfvTitle:ControlToValidate(txtTitle)、ErrorMessage(“标题必须输入。”)
rfvContent:ControlToValidate(txtTitle)、ErrorMessage(“内容必须输入。”)
第八天
学习目的
cmd.Parameters.Add("@Title", SqlDbType.NVarChar, 50);
cmd.Parameters.Add("@SubTitle", SqlDbType.NVarChar, 50);
cmd.Parameters.Add("@Writer", SqlDbType.NVarChar, 10);
cmd.Parameters.Add("@Content", SqlDbType.NText);
cmd.Parameters["@Title"].value = txtTitle.Text.Trim();
if (txtSubTitle.Text == string.Empty || txtSubTitle.Text.Trim() == "")
{
cmd.Parameters["@SubTitle"].value = DBNull.value;
}
else
{
cmd.Parameters["@SubTitle"].value = txtSubTitle.Text.Trim();
}
if (txtWriter.Text == string.Empty || txtWriter.Text.Trim() == "")
{
cmd.Parameters["@Writer"].value = DBNull.value;
}
else
{
cmd.Parameters["@Writer"].value = txtWriter.Text;
}
cmd.Parameters["@Content"].value = txtContent.Text;
cmd.Parameters.Add("@Title", SqlDbType.NVarChar, 50) .value = txtTitle.Text.Trim();
这要看你喜欢了。 private void btnPublish_ServerClick(object sender, System.EventArgs e)
{
string strConnection = ConfigurationSettings.AppSettings["SqlDatabase1"];
// 连接SqlServer数据库
SqlConnection conn = new SqlConnection(strConnection);
// 建立SqlCommand
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "INSERT INTO NewsArticle (Title, SubTitle, Writer, Content)"
+ " valueS ( @Title, @SubTitle, @Writer, @Content )";
conn.Open();
cmd.Parameters.Add("@Title", SqlDbType.NVarChar, 50);
cmd.Parameters.Add("@SubTitle", SqlDbType.NVarChar, 50);
cmd.Parameters.Add("@Writer", SqlDbType.NVarChar, 10);
cmd.Parameters.Add("@Content", SqlDbType.NText);
cmd.Parameters["@Title"].value = txtTitle.Text.Trim();
if (txtSubTitle.Text == string.Empty || txtSubTitle.Text.Trim() == "")
{
cmd.Parameters["@SubTitle"].value = DBNull.value;
}
else
{
cmd.Parameters["@SubTitle"].value = txtSubTitle.Text.Trim();
}
if (txtWriter.Text == string.Empty || txtWriter.Text.Trim() == "")
{
cmd.Parameters["@Writer"].value = DBNull.value;
}
else
{
cmd.Parameters["@Writer"].value = txtWriter.Text;
}
cmd.Parameters["@Content"].value = txtContent.Text;
// 插入记录
try
{
cmd.ExecuteNonQuery();
}
catch (Exception ex)
{
Response.Write("<script language=javascript>alert("输入错误,数据库不能更新。")</script>");
}
finally
{
conn.Close();
}
}