Siverlight 4 中的无尽加载屏幕

Question

编译和运行后，当我尝试在 Google Chrome 或 Mozilla Firefox 中加载页面时，它只显示蓝色的进度，在圆圈中旋转，一瞬间它会显示一个百分比，然后消失

整个登录页面的代码

public partial class LoginPage : UserControl
    {
        public bool UsernameExists = false;
        public bool PasswordExists = false;
        public bool SchoolExists = false;
        public LoginPage()
        {
            InitializeComponent();
        }

        private void username_autocompletebox_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            //Checks if user entered all neccessary values, enables Login_button if so
            if (username_autocompletebox.Text.Length != 0)
            {
                UsernameExists = true;
            }
            else
            {
                UsernameExists = false;
            }
            if (UsernameExists = true && PasswordExists == true && SchoolExists == true)
            {
                Login_button.IsEnabled = true;
            }
            else
            {
                Login_button.IsEnabled = false;
            }
        }

        private void password_passwordbox_PasswordChanged(object sender, RoutedEventArgs e)
        {
            //Checks if user entered all neccessary values, enables Login_button if so
            if (password_passwordbox.Password.Length != 0)
            {
                PasswordExists = true;
            }
            else
            {
                PasswordExists = false;
            }
            if (UsernameExists = true && PasswordExists == true && SchoolExists == true)
            {
                Login_button.IsEnabled = true;
            }
            else
            {
                Login_button.IsEnabled = false;
            }
        }

        private void school_combobox_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            //Checks if user entered all neccessary values, enables Login_button if so
            if (school_combobox.SelectedItem != null && school_combobox.SelectedItem.ToString() != "Select a School")
            {
                SchoolExists = true;
            }
            else
            {
                SchoolExists = false;
            }
            if (UsernameExists = true && PasswordExists == true && SchoolExists == true)
            {
                Login_button.IsEnabled = true;
            }
            else
            {
                Login_button.IsEnabled = false;
            }
        }

        private void Login_button_Click(object sender, RoutedEventArgs e)
        {
            Authenticate Authenticator = new Authenticate();
            User CurrentUser = Authenticator.Login(username_autocompletebox.Text, password_passwordbox.Password, school_combobox.SelectedItem.ToString());
        }
    }

Answer 1

很可能在 Application_UnHandledException 中处理未处理的异常。在您的 Application_UnHandledException 处理程序中放置一个断点以查看问题，或者在 VS 打开未处理异常抛出时的通知。您还可以在浏览器中找到堆栈跟踪来查看问题。当 XAML 某处不正确时，通常会发生这种情况。引用可能不存在的事件处理程序或样式等...