//类设计;
using System;
using System.Collections.Generic;
using System.Text;
using System.Data.SqlClient;namespace helloCsharp
{//定义验证连接数据库来验证用户合法性的类Verify
class Verify
{
private string s_uid;
private string s_pwd;
public string uid //uid属性
{
get
{
return s_uid;
}
set
{
if (s_uid != value)
s_uid = value;
}
}
public string pwd//密码属性
{
get
{
return s_pwd;
}
set
{
if (s_uid != value)
s_pwd = value;
}
} //定义验证方法erify
public int uidVerify()
{
int i;
SqlConnection conn = new SqlConnection("server=(local);database=DB_CFGL;User ID=sa;Password=houyichong");
conn.Open();
SqlCommand cmd = new SqlCommand("select flag from T_user where uid='"+s_uid+"' and pwd='"+s_pwd+"'",conn );
SqlDataReader dr = new SqlDataReader();
dr =cmd.ExecuteReader();
if (dr.Read())//如果有记录就获取权限;
i=(int)dr["flag"];//存在用户,返回该用户记录中flag的值
else
i=0; //没有用户返回0
//释放数据库资源
//cmd.Dispose();
dr.Close();
conn.Close();
return i;
}
} }//按钮事件调用
private void btn_login_Click(object sender, EventArgs e)
{
Verify m_verify = new Verify();
m_verify.uid = txt_uid.Text.ToString();
m_verify.pwd = txt_pwd.Text.ToString();
int x;
x = m_verify.uidVerify();//调用对象m_verify的uidVerify();方法
if (x > 0) //连接失败返回0,成功返回对应的权限值
MessageBox.Show("ok");
}//报错代码:从连接数据库部分开始就出错.
/*
SqlConnection conn = new SqlConnection("server=(local);database=DB_CFGL;User ID=sa;Password=houyichong");
conn.Open();
SqlCommand cmd = new SqlCommand("select flag from T_user where uid='"+s_uid+"' and pwd='"+s_pwd+"'",conn );
SqlDataReader dr = new SqlDataReader();
dr =cmd.ExecuteReader();
if (dr.Read())//如果有记录就获取权限;
i=(int)dr["flag"];//存在用户,返回该用户记录中flag的值
else
i=0; //没有用户返回0*/
//报错内容:错误 1 类型“System.Data.SqlClient.SqlDataAdapter”同时存在于“c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\System.Data.dll”和“c:\Program Files\Microsoft Visual Studio 8\Common7\IDE\PublicAssemblies\System.Data.SqlClient.dll”中 D:\C#Practices\helloCsharp\helloCsharp\DB_CFGLDataSet.Designer.cs 564 39 helloCsharp
using System;
using System.Collections.Generic;
using System.Text;
using System.Data.SqlClient;namespace helloCsharp
{//定义验证连接数据库来验证用户合法性的类Verify
class Verify
{
private string s_uid;
private string s_pwd;
public string uid //uid属性
{
get
{
return s_uid;
}
set
{
if (s_uid != value)
s_uid = value;
}
}
public string pwd//密码属性
{
get
{
return s_pwd;
}
set
{
if (s_uid != value)
s_pwd = value;
}
} //定义验证方法erify
public int uidVerify()
{
int i;
SqlConnection conn = new SqlConnection("server=(local);database=DB_CFGL;User ID=sa;Password=houyichong");
conn.Open();
SqlCommand cmd = new SqlCommand("select flag from T_user where uid='"+s_uid+"' and pwd='"+s_pwd+"'",conn );
SqlDataReader dr = new SqlDataReader();
dr =cmd.ExecuteReader();
if (dr.Read())//如果有记录就获取权限;
i=(int)dr["flag"];//存在用户,返回该用户记录中flag的值
else
i=0; //没有用户返回0
//释放数据库资源
//cmd.Dispose();
dr.Close();
conn.Close();
return i;
}
} }//按钮事件调用
private void btn_login_Click(object sender, EventArgs e)
{
Verify m_verify = new Verify();
m_verify.uid = txt_uid.Text.ToString();
m_verify.pwd = txt_pwd.Text.ToString();
int x;
x = m_verify.uidVerify();//调用对象m_verify的uidVerify();方法
if (x > 0) //连接失败返回0,成功返回对应的权限值
MessageBox.Show("ok");
}//报错代码:从连接数据库部分开始就出错.
/*
SqlConnection conn = new SqlConnection("server=(local);database=DB_CFGL;User ID=sa;Password=houyichong");
conn.Open();
SqlCommand cmd = new SqlCommand("select flag from T_user where uid='"+s_uid+"' and pwd='"+s_pwd+"'",conn );
SqlDataReader dr = new SqlDataReader();
dr =cmd.ExecuteReader();
if (dr.Read())//如果有记录就获取权限;
i=(int)dr["flag"];//存在用户,返回该用户记录中flag的值
else
i=0; //没有用户返回0*/
//报错内容:错误 1 类型“System.Data.SqlClient.SqlDataAdapter”同时存在于“c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\System.Data.dll”和“c:\Program Files\Microsoft Visual Studio 8\Common7\IDE\PublicAssemblies\System.Data.SqlClient.dll”中 D:\C#Practices\helloCsharp\helloCsharp\DB_CFGLDataSet.Designer.cs 564 39 helloCsharp
SqlDataReader dr = new SqlDataReader();
.
.
.
dr.Close();2 Anders_lt(突破渴望)
System.Data地址是C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\System.Data.dll
System.Data.SqlClient地址是:C:\Program Files\Microsoft Visual Studio 8\Common7\IDE\PublicAssemblies\System.Data.SqlClient.dll
1.数据库正确否?
2.表名、字段名是否和关键字有冲突,最好要中括号括起来;//嫌疑最大因为用了Password
//flag等
3.类库引出对象没有初始化;