我试图在登录程序时打开“加载”窗口。一切都只能正确运行一次。第二次运行它时，出现错误：System.InvalidOperationException：调用线程无法访问此对象，因为它属于另一个线程。请帮忙...
ViewModel.cs
private ProszeCzekaj proszeCzekaj;
private async void ZalogujExecute(object obj)
{
try
{
Thread tbr = new Thread(() =>
{
proszeCzekaj = new ProszeCzekaj();
proszeCzekaj.Closed += (sender2, e2) =>
proszeCzekaj.Dispatcher.InvokeShutdown();
proszeCzekaj.Show();
Dispatcher.Run();
});
tbr.SetApartmentState(ApartmentState.STA); //required for WPF
tbr.Start();
var odp = await SprawdzLogowanie();
if (odp==1)
{
}
proszeCzekaj.Dispatcher.Invoke(proszeCzekaj.Window2Close);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
async Task<int> SprawdzLogowanie()
{
await Task.Run(() =>
{
AplikacjaDbContext db = new AplikacjaDbContext();
foreach (var user in db.UsersTable.ToList())
{
MessageBox.Show(user.userLogin); //for test
}
});
return 1;
}
Logowani.xaml.cs
namespace PGSQL.View
{
/// <summary>
/// Logika interakcji dla klasy Logowanie.xaml
/// </summary>
public delegate void dWindow2Close();
public partial class Logowanie : Window
{
public Logowanie()
{
InitializeComponent();
LogowanieViewModel model = new LogowanieViewModel();
this.DataContext = model;
}
}
}
正在加载.xaml.cs
namespace PGSQL.View
{
/// <summary>
/// Logika interakcji dla klasy ProszeCzekaj.xaml
/// </summary>
public partial class ProszeCzekaj : Window
{
public dWindow2Close Window2Close;
public ProszeCzekaj()
{
InitializeComponent();
Window2Close = new dWindow2Close(SecondWindowClose);
IntPtr hWnd = new WindowInteropHelper(GetWindow(this)).EnsureHandle();
var attribute = DWMWINDOWATTRIBUTE.DWMWA_WINDOW_CORNER_PREFERENCE;
var preference = DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_ROUND;
DwmSetWindowAttribute(hWnd, attribute, ref preference, sizeof(uint));
ProszeCzekajViewModel model = new ProszeCzekajViewModel();
this.DataContext = model;
}
private void SecondWindowClose()
{
this.Close();
}
public enum DWMWINDOWATTRIBUTE
{
DWMWA_WINDOW_CORNER_PREFERENCE = 33
}
// The DWM_WINDOW_CORNER_PREFERENCE enum for DwmSetWindowAttribute's third parameter, which tells the function
// what value of the enum to set.
// Copied from dwmapi.h
public enum DWM_WINDOW_CORNER_PREFERENCE
{
DWMWCP_DEFAULT = 0,
DWMWCP_DONOTROUND = 1,
DWMWCP_ROUND = 2,
DWMWCP_ROUNDSMALL = 3
}
// Import dwmapi.dll and define DwmSetWindowAttribute in C# corresponding to the native function.
[DllImport("dwmapi.dll", CharSet = CharSet.Unicode, PreserveSig = false)]
internal static extern void DwmSetWindowAttribute(IntPtr hwnd,
DWMWINDOWATTRIBUTE attribute,
ref DWM_WINDOW_CORNER_PREFERENCE pvAttribute,
uint cbAttribute);
}
}