㈠ C# 写一个winform登录与注册的应用程序
登录就是判断你输入的值和数据库中的值是否相同,而注册其实就是往数据库中插入用户名和密码,比如注册代码如下,导入命名空间using System.Data.SqlClient;
SqlConnection conn = new SqlConnection();
conn.ConnectionString = "server=.;database=数据库名;uid=用户名;pwd=密码;";
string strcmd = "insert into 用户表 values('" + TextBox1.Text + "','" + TextBox2.Text + "')";
SqlCommand mycommand = new SqlCommand(strcmd, conn);
try
{
conn.Open();
mycommand.ExecuteNonQuery();
MessageBox.Show(" 注册成功 ");
}
catch
{
MessageBox.Show("注册发生错误");}
finally
{
conn.Close();
}
㈡ 求VS2010 C#FORM编写强制关机代码 只要关机的
using System.Runtime.InteropServices; // 提供DllImport等特性，是P/Invoke的关键
// 这个结构体将会传递给API。使用StructLayout(...特性，确保其中的成员是按顺序排列的，C#编译器不会对其进行调整。
[StructLayout(LayoutKind.Sequential, Pack = 1)]
internal struct TokPriv1Luid
{
public int Count;
public long Luid;
public int Attr;
}
// 以下使用DllImport特性导入了所需的Windows API。
// 导入的方法必须是static extern的，并且没有方法体。调用这些方法就相当于调用Windows API。
[DllImport("kernel32.dll", ExactSpelling = true)]
internal static extern IntPtr GetCurrentProcess();
[DllImport("advapi32.dll", ExactSpelling = true, SetLastError = true)]
internal static extern bool OpenProcessToken(IntPtr h, int acc, ref IntPtr phtok);
[DllImport("advapi32.dll", SetLastError = true)]
internal static extern bool LookupPrivilegeValue(string host, string name, ref long pluid);
[DllImport("advapi32.dll", ExactSpelling = true, SetLastError = true)]
internal static extern bool AdjustTokenPrivileges(IntPtr htok, bool disall,
ref TokPriv1Luid newst, int len, IntPtr prev, IntPtr relen);
[DllImport("user32.dll", ExactSpelling = true, SetLastError = true)]
internal static extern bool ExitWindowsEx(int flg, int rea);
// 以下定义了在调用WinAPI时需要的常数。这些常数通常可以从Platform SDK的包含文件（头文件）中找到
internal const int SE_PRIVILEGE_ENABLED = 0x00000002;
internal const int TOKEN_QUERY = 0x00000008;
internal const int TOKEN_ADJUST_PRIVILEGES = 0x00000020;
internal const string SE_SHUTDOWN_NAME = "SeShutdownPrivilege";
internal const int EWX_LOGOFF = 0x00000000;
internal const int EWX_SHUTDOWN = 0x00000001;
internal const int EWX_REBOOT = 0x00000002;
internal const int EWX_FORCE = 0x00000004;
internal const int EWX_POWEROFF = 0x00000008;
internal const int EWX_FORCEIFHUNG = 0x00000010;
// 通过调用WinAPI实现关机，主要代码再最后一行ExitWindowsEx，这调用了同名的WinAPI，正好是关机用的。
private static void DoExitWin(int flg)
{
bool ok;
TokPriv1Luid tp;
IntPtr hproc = GetCurrentProcess();
IntPtr htok = IntPtr.Zero;
ok = OpenProcessToken(hproc, TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, ref htok);
tp.Count = 1;
tp.Luid = 0;
tp.Attr = SE_PRIVILEGE_ENABLED;
ok = LookupPrivilegeValue(null, SE_SHUTDOWN_NAME, ref tp.Luid);
ok = AdjustTokenPrivileges(htok, false, ref tp, 0, IntPtr.Zero, IntPtr.Zero);
ok = ExitWindowsEx(flg, 0);
}
private void button1_Click(object sender, EventArgs e)
{
DoExitWin(EWX_SHUTDOWN);
}