[英]WPF: Set MainWindow in App.xaml.cs, access it's variables
過去,我可以在關閉時訪問Windows變量,就像返回參數一樣。 但目前與此有關。 請參見下面的代碼:
public partial class App : Application
{
//Public list of users and form can access
ObservableCollection<User> LoggedUsers = new ObservableCollection<User>();
public ObservableCollection<User> Logged
{
get
{
return LoggedUsers;
}
}
protected override void OnStartup(System.Windows.StartupEventArgs e)
{
if (!AreSettingsSet())
{
this.MainWindow = new Views.LoginWindow();
this.MainWindow.ShowDialog(); // Waits until closed.
//If the login form was closed properly, handle the user
if (MainWindow.DialogResult == true)
{
//Add the user to the list of logged users
User returned = MainWindow.returnUser;
LoggedUsers.Add(returned);
}
// Recheck the settings now that the login screen has been closed.
if (!AreSettingsSet())
{
// Tell the user there is a problem and quit.
this.Shutdown();
}
}
this.MainWindow = new Views.Main();
this.MainWindow.Show();
}
private bool AreSettingsSet()
{
MessageBox.Show(Logged.Count().ToString());
return false;
}
}
如果AreSettingsSet
方法返回false(目前正在測試),則此代碼應打開登錄窗口。 這很好用,我在從Views.LoginWindow()
窗口Views.LoginWindow()
對象時遇到問題,這里是代碼:
//Give App access to user object outside of this form
public User returnUser
{
get
{
return user;
}
}
//Public user object, start empty
User user = new User();
我要去哪里錯了? 如何從登錄窗口獲取LoggedUsers
對象? 目前,我在下一行出現錯誤。
碼:
User returned = MainWindow.returnUser;
錯誤:
'System.Windows.Window'不包含'returnUser'的定義,也找不到擴展方法'returnUser'接受類型為'System.Windows.Window'的第一個參數(是否缺少using指令或程序集引用?)
該框架將LoginWindow存儲為Window 。
您可以將MainWindow強制轉換為LoginWindow
User returned = ((Views.LoginWindow)MainWindow).returnUser;
或使用as運算子
User returned = (MainWindow as Views.LoginWindow).returnUser;
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