C# WinForm界面上实现按条件检索数据

实现步骤:

1.定义事件

2.定义方法

3.完善步骤2中的方法

　　1)在步骤2中的参数方法,定义参数方法,主要获取界面查询条件

　　2)实现在步骤2中的数据SQL查询语句方法



实例操作如下:

1.定义事件

btnSelectUserList.Click += btnSelectUserList_Click;

2.定义方法

void btnSelectUserList_Click(object sender, EventArgs e)
{
SelectUserList();
}

3.完善步骤2中的方法

private void SelectUserList()
{
UserService userService = new UserService();
DataTable userTable = userService.GetUserList(GetWhereUser());
bindingSource.DataSource = userTable;
gridControl1.DataSource = bindingSource;
}

　　1)在步骤2中的参数方法,定义参数方法,主要获取界面查询条件

private string GetWhereUser()
{
string strWhere = string.Empty;
if (txt_UserName.Text.Trim() != "")
strWhere += string.Format(" and Users.UserName like '%{0}%'", txt_UserName.Text.Trim());
if (this.time_LoginStart.Checked && this.time_LoginEnd.Checked)
strWhere += string.Format(" and Users.DateCreated between '{0}' and '{1}'",
this.time_LoginStart.Text, this.time_LoginEnd.Text);
if (this.time_LoginStart.Checked)
strWhere += string.Format(" and Users.DateCreated >= '{0}'", this.time_LoginStart.Text);
if (this.time_LoginEnd.Checked)
strWhere += string.Format(" and Users.DateCreated <= '{0}'", this.time_LoginEnd.Text);
return strWhere;

}

　　2)实现在步骤2中的数据SQL查询语句方法

/// <summary>
/// 检索本地用户列表
/// </summary>
/// <param name="strWhere"></param>
/// <returns></returns>
public DataTable GetUserList(string strWhere)
{
DataTable table = new DataTable();
try
{
string strSql = string.Format(@"select Users.UserId,Users.UserName,users.AuthenticationMode,users.RoleId,users.DisplayName,users.Email,
Users.PhoneNumber,users.Status,users.DateLastLogon,users.CreatedBy,users.DateModifed
from Users where users.Status=1");
strSql += strWhere;
table = DataBase.Default.ExecuteDataTable(strSql, CommandType.Text);
}
catch(Exception ex)
{
throw new Exception("" + ex.Message + ex.StackTrace);
}
return table;
}

下面是一个数据库操作的基础类(DBHelper)的一个方法

public DataTable ExecuteDataTable(string strSql, CommandType commandType)
{
DataTable table = new DataTable();
try
{
table = ExecuteDataTable(strSql, null, true);
}
catch (Exception ex)
{
log.Error("DB:" + GetKey() + Environment.NewLine + "SQL:" + strSql + Environment.NewLine + ex);
throw new Exception("错误信息：" + ex.Message + ex.StackTrace);
}
return table;
}

杂记:下面演示的是通过消息请求反应机制,按检索消息传过来的数据列表(用户名,创建时间的阶段).

private void SelectUserList()
{
//string str = "UserName '{0}%'";
//str = string.Format(str, txt_UserName.Text.Trim());
List<UserInfo> userInfoList = message.UserInfoList;
if (!string.IsNullOrEmpty(txt_UserName.Text.Trim()))
{
userInfoList = message.UserInfoList.FindAll(c => c.UserName.StartsWith(txt_UserName.Text.Trim()));
}
if (this.time_LoginStart.Checked)
userInfoList = userInfoList.FindAll(c => c.DateCreated.Value > time_LoginStart.Text.ToDateTime());
if (this.time_LoginEnd.Checked)
userInfoList = userInfoList.FindAll(c => c.DateCreated.Value < time_LoginEnd.Text.ToDateTime());
bindingSource.DataSource = userInfoList;
gridControl1.DataSource = bindingSource;
gridView1.RefreshData();
return;

}