/// <summary>
/// 能否开始一个互斥操作,用完后请CloseMutex()
/// </summary>
/// <param name="om"></param>
/// <param name="hasErrorPrompt"></param>
/// <returns></returns>
public bool StartMutex(ObjectMutex om, bool hasErrorPrompt)
{
MutexStatus stat = GetMutexState(om, true);
if (stat == MutexStatus.进行中)
{
if (hasErrorPrompt)
{
System.Windows.Forms.MessageBox.Show("用户[" + om.UserName + "]正在 " + om.Digest + ", 预计至多剩余" + om.Timeout + "秒. \n\n" + "本次操作被终止, 请稍后再继续执行.", "检查并发操作", System.Windows.Forms.MessageBoxButtons.OK, System.Windows.Forms.MessageBoxIcon.Information);
}
return(false);
}
return(true);
}
/// <summary>检查互斥. 在allowBeginMutex=true时,用完后请CloseMutex()
/// ,互斥表ObjectMutex字段:ID=LC.Bal.Sum.Year.Term;BeginTime:起始点(服务器时间);EndTime:完成点(服务器时间);TimeOut:超时秒;UseName:用户名,
/// 判断是否互斥 只需要检查(serverdatetime-begintime)是否>timeout即可,
/// EndTime可以不填
/// </summary>
/// <param name="ID"></param>
/// <param name="timeOutSec"></param>
/// <param name="UserName"></param>
/// <param name="Digest"></param>
/// <param name="allowBeginMutex"></param>
/// <returns></returns>
public MutexStatus GetMutexState(ObjectMutex om, bool allowBeginMutex)
{
int i = 0;
MutexStatus b;
#region 建立互斥表
if (!ExistTable("ObjectMutex"))
{
i = 0;
DataColumnEx[] cols = new DataColumnEx[6];
cols[i] = new DataColumnEx();
cols[i].ColumnName = "ID";//对象类型
cols[i].DataType = DbType.String;
i++;
cols[i] = new DataColumnEx();
cols[i].ColumnName = "BeginTime";//对象枚举
cols[i].DataType = DbType.DateTime;
i++;
cols[i] = new DataColumnEx();
cols[i].ColumnName = "EndTime";//系统内置
cols[i].DataType = DbType.DateTime;
cols[i].AllowDBNull = true;
i++;
cols[i] = new DataColumnEx();
cols[i].ColumnName = "TimeOut";//对象类型
cols[i].DataType = DbType.Int32;
i++;
cols[i] = new DataColumnEx();
cols[i].ColumnName = "UserName";//对象枚举
cols[i].DataType = DbType.String;
i++;
cols[i] = new DataColumnEx();
cols[i].ColumnName = "Digest";//系统内置
cols[i].DataType = DbType.String;
CreateTable("ObjectMutex", cols, new string[1] {
"ID"
});
}
#endregion
StringBuilder sb = new StringBuilder();
sb.Append("select datediff(s,BeginTime,T2.d) as dd,TimeOut,UserName,Digest from (");
sb.Append(" SELECT getdate() as d,BeginTime,TimeOut,UserName,Digest from ObjectMutex");
sb.Append(" Where ID='" + om.ID);
sb.Append("') T2");
string sql = sb.ToString();
SqlCommand cm = new SqlCommand(sql, _dbConn);
SqlDataReader rs = cm.ExecuteReader();
if (!rs.HasRows)
{
b = MutexStatus.停止;
}
else
{
rs.Read();
int d = int.Parse(rs.GetValue(0).ToString());
int to = int.Parse(rs.GetValue(1).ToString());
if (d > to)
{
b = MutexStatus.停止;
}
else
{
om.UserName = rs.GetString(2).Trim();
om.Digest = rs.GetString(3).Trim();
om.Timeout = to - d;
b = MutexStatus.进行中;
}
}
rs.Close();
if (b == MutexStatus.停止 && allowBeginMutex)
{
cm = new SqlCommand("delete from ObjectMutex Where ID='" + om.ID + "'", _dbConn);
cm.ExecuteNonQuery();
sb = new StringBuilder();
sb.Append("INSERT INTO ObjectMutex ([ID], [BeginTime], [TimeOut], [UserName], [Digest])");
sb.Append(" VALUES('");
sb.Append(om.ID);
sb.Append("', getdate() ,");
sb.Append(om.Timeout);
sb.Append(",'" + om.UserName);
sb.Append("','" + om.Digest + "')");
sql = sb.ToString();
cm = new SqlCommand(sql, _dbConn);
i = cm.ExecuteNonQuery();
if (i > 0)
{
b = MutexStatus.开始;
}
}
return(b);
}
