C# WPF-级联组合框不工作 XAML DataContext.cs 公共列表GetServer(字符串服务器) { var keys=ConfigurationManager.AppSettings.keys; returnkeys.Cast() .Where(key=>key.ToString().ToLower()) .Contains(server.ToLower()) .Select(key=>ConfigurationManager.AppSettings.Get(key.ToString()).ToList(); }
函数根据在第一个组合框中选择的服务器名称填充第二个组合框C# WPF-级联组合框不工作 XAML DataContext.cs 公共列表GetServer(字符串服务器) { var keys=ConfigurationManager.AppSettings.keys; returnkeys.Cast() .Where(key=>key.ToString().ToLower()) .Contains(server.ToLower()) .Select(key=>ConfigurationManager.AppSettings.Get(key.ToString()).ToList(); },c#,wpf,combobox,cascading,C#,Wpf,Combobox,Cascading,函数根据在第一个组合框中选择的服务器名称填充第二个组合框 public List GetDBNames(字符串sqlServerName) { List lstDBName=新列表(); sqlServerName=openconn().DataSource; SqlConnectionStringBuilder连接=新的SqlConnectionStringBuilder(); connection.DataSource=sqlServerName; connectio
public List GetDBNames(字符串sqlServerName)
{
List lstDBName=新列表();
sqlServerName=openconn().DataSource;
SqlConnectionStringBuilder连接=新的SqlConnectionStringBuilder();
connection.DataSource=sqlServerName;
connection.IntegratedSecurity=true;
String strCon=connection.ToString();
SqlConnection sqlConn=新的SqlConnection(strCon);
sqlConn.Open();
SqlCommand cmd=newsqlcommand(“从sys.databases中选择*”,sqlConn);
SqlDataReader dr=cmd.ExecuteReader();
while(dr.Read())
{
lstDBName.Add(dr[0].ToString());
}
sqlConn.Close();
返回lstDBName;
}
BackupViewModel.cs
List\u服务器名称列表;
列表_DBNameList;
公共列表服务器名称列表
{
获取{return\u ServerNameList;}
设置
{
_ServerNameList=值;
}
}
公共列表DBNameList
{
获取{return\u DBNameList;}
设置
{
_DBNameList=值;
}
}
选择字符串_serverSelected;
已选择公共字符串服务器
{
获取{return\u serverSelected;}
设置
{
如果(_serverSelected!=值)
_serverSelected=值;
RaisePropertyChanged(“服务器选定”);
}
}
公共备份视图模型()
{
BackUpContext servObj=新的BackUpContext();
_ServerNameList=servObj.GetServer(“ServerName”);
_DBNameList=servObj.GetDBNames(serverSelected);
serverCommand=newrelaycommand(fetchServer);
}
公共RelayCommand服务器命令{get;set;}
公共服务器(对象服务器)
{
serverSelected=server.ToString();
}
serverCommand=newrelaycommand(fetchServer);
我无法填充根据在第一个组合框中选择的值过滤的第二个组合框。我是否正确绑定了两个组合框
您已经将第二个组合框绑定到名为DBNameList的属性 您还没有为此写任何RaiseProperty更改 你的财产是这样的
List<string> _ServerNameList;
List<string> _DBNameList;
public List<string> ServerNameList
{
get { return _ServerNameList; }
set
{
_ServerNameList = value;
}
}
public List<string> DBNameList
{
get { return _DBNameList; }
set
{
_DBNameList = value;
}
}
string _serverSelected;
public string serverSelected
{
get { return _serverSelected; }
set
{
if ( _serverSelected!=value)
_serverSelected = value;
RaisePropertyChanged("serverSelected");
}
}
public BackUpViewModel()
{
BackUpContext servObj = new BackUpContext();
_ServerNameList = servObj.GetServer("ServerName");
_DBNameList = servObj.GetDBNames(serverSelected);
serverCommand = new RelayCommand(fetchServer);
}
public RelayCommand serverCommand { get; set; }
public void fetchServer(object server)
{
serverSelected = server.ToString();
}
serverCommand = new RelayCommand(fetchServer);
公共列表DBNameList
{
获取{return\u DBNameList;}
设置
{
if(_DBNameList!=值)
{
_DBNameList=值;
RaisePropertyChanged(“数据库名称列表”);
}
}
}
运行时发生了什么?你期望发生什么?@Xiao:如果我在第一个组合框中选择任何值,第二个组合框中始终填充相同的数据库名称值。我希望根据第一个组合框中的选择,过滤第二个组合框,然后填充;此语句导致我出错,因为我的系统中只有一台服务器。因此,当我选择任何其他需要该数据库列表的服务器时,第二个组合框变为空。错误:在GetDBname()中:{“值不能为空。\r\n参数名称:数据源”}在GetDBname函数中放置一个断点,并查看此函数中的空值。我希望服务器选定的值应传递给H GetDBname()。然后将新数据源设置到所选服务器,构建新连接字符串并检索该服务器中的数据库。目前,连接字符串中提到的数据源总是作为参数传递给getDBNames()。所以每次提取相同的数据库时。
public List<string> GetServer(string server)
{
var keys = ConfigurationManager.AppSettings.Keys;
return keys.Cast<object>()
.Where(key => key.ToString().ToLower()
.Contains(server.ToLower()))
.Select(key => ConfigurationManager.AppSettings.Get(key.ToString())).ToList();
}
public List<string> GetDBNames(string sqlServerName)
{
List<string> lstDBName = new List<string>();
sqlServerName = openconn().DataSource;
SqlConnectionStringBuilder connection = new SqlConnectionStringBuilder();
connection.DataSource = sqlServerName;
connection.IntegratedSecurity = true;
String strCon = connection.ToString();
SqlConnection sqlConn = new SqlConnection(strCon);
sqlConn.Open();
SqlCommand cmd = new SqlCommand("select * from sys.databases", sqlConn);
SqlDataReader dr = cmd.ExecuteReader();
while (dr.Read())
{
lstDBName.Add(dr[0].ToString());
}
sqlConn.Close();
return lstDBName;
}
List<string> _ServerNameList;
List<string> _DBNameList;
public List<string> ServerNameList
{
get { return _ServerNameList; }
set
{
_ServerNameList = value;
}
}
public List<string> DBNameList
{
get { return _DBNameList; }
set
{
_DBNameList = value;
}
}
string _serverSelected;
public string serverSelected
{
get { return _serverSelected; }
set
{
if ( _serverSelected!=value)
_serverSelected = value;
RaisePropertyChanged("serverSelected");
}
}
public BackUpViewModel()
{
BackUpContext servObj = new BackUpContext();
_ServerNameList = servObj.GetServer("ServerName");
_DBNameList = servObj.GetDBNames(serverSelected);
serverCommand = new RelayCommand(fetchServer);
}
public RelayCommand serverCommand { get; set; }
public void fetchServer(object server)
{
serverSelected = server.ToString();
}
serverCommand = new RelayCommand(fetchServer);
public List<string> DBNameList
{
get { return _DBNameList; }
set
{
if(_DBNameList != value)
{
_DBNameList = value;
RaisePropertyChanged("DBNameList");
}
}
}