我找到了这个：How to show a loading graphic/animation when wpf data binding is taking place
但不明白如何将它应用于我的工作。
我有我的主窗口。它会调用我的所有用户控件。
在用户控件上，我有一个DataGrid。按“Go”按钮后，datagrid从MySQL加载数据。这需要很长时间，我想在加载datagrig期间显示一个带有“Please Wait”的对话窗口。
我找到了以下链接，但不明白如何正确调用它。
我是否需要将此“加载器”放在像“Loader.cs”这样的新类文件中并按下它？好的，但是在datagrid完成时如何关闭它？
我迷路了......好吧，如果存在另一种解决方案，只需使用......
先谢谢
编辑测试1：
尝试使用滑块进行简单测试以获得等待时间和按钮。
using System;
using System.ComponentModel;
using System.Windows;
using System.Windows.Controls;
namespace TEST_LoadingPage
{
/// <summary>
/// Logique d'interaction pour MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void btnTester_Click(object sender, RoutedEventArgs e)
{
Window waitWindow = new Window { Height = 100, Width = 200, WindowStartupLocation = WindowStartupLocation.CenterScreen, WindowStyle = WindowStyle.None };
waitWindow.Content = new TextBlock { Text = "Veuillez patienter...", FontSize = 30, HorizontalAlignment = HorizontalAlignment.Center, VerticalAlignment = VerticalAlignment.Center };
BackgroundWorker worker = new BackgroundWorker();
worker.DoWork += delegate
{
Dispatcher.BeginInvoke(new Action(delegate { waitWindow.ShowDialog(); }));
lbReussite.Visibility = Loop.Pause(slider.Value);
Dispatcher.BeginInvoke(new Action(delegate() { waitWindow.Close(); }));
};
worker.RunWorkerAsync();
}
}
public class Loop
{
public static System.Windows.Visibility Pause(double duree)
{
try
{
DateTime begin = new DateTime();
DateTime end = new DateTime();
int i = 0;
begin = DateTime.Now;
end = DateTime.Now.AddSeconds(duree);
while (DateTime.Now <= end)
i++;
return System.Windows.Visibility.Visible;
}
catch (Exception)
{
return System.Windows.Visibility.Hidden;
}
}
}
}
但不能处理错误：
调用线程无法访问此对象，因为另一个线程拥有它
我知道它有一个courant错误，但我没有看到“DispatcherTimer”或者我之前见过的先例项目...所以我明天会尝试第二个代码但是。我不明白我把方法放在哪里：（
编辑2
我尝试了你的代码......我太愚蠢了。
我在Loader.cs和我的MainWiondow中编写了这个类（它是一个测试）
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void btnTester_Click(object sender, RoutedEventArgs e)
{
Loader<List<Donnees>> loader = new Loader<List<Donnees>>(GenerateList((int)slider.Value);
loader.JobFinished += new Loader<Donnees>.OnJobFinished(loader_JobFinished);
loader.Load();
}
private List<Donnees> GenerateList(int number)
{
List<Donnees> list = new List<Donnees>();
for (int i = 1; i <= number; i++)
{
Donnees data = new Donnees();
data.Id = i;
data.Name = "Ligne " + i;
list.Add(data);
}
return list;
}
void loader_JobFinished(object sender, List<Donnees> result)
{
result = GenerateList((int)slider.Value);
dgDataGrid.ItemsSource = result;
}
}
public class Donnees
{
#region Properties
private int id;
public int Id
{
get { return id; }
set { id = value; }
}
private string name;
public string Name
{
get { return name; }
set { name = value; }
}
#endregion
public Donnees()
{
id = -1;
name = "";
}
}
答案 0 :(得分：2)
您将以下代码放在DataGrid-UserControl的代码隐藏中的方法中，该方法在您的button-click-eventhandler中调用：
Window waitWindow = new Window { Height = 100, Width = 200, WindowStartupLocation = WindowStartupLocation.CenterScreen, WindowStyle = WindowStyle.None };
waitWindow.Content = new TextBlock { Text = "Please Wait", FontSize = 30, FontWeight = FontWeights.Bold, HorizontalAlignment = HorizontalAlignment.Center, VerticalAlignment = VerticalAlignment.Center };
现在你可以决定......
...如果要创建一个DataLoader类，它在完成时加载数据并触发DataLoaded事件，而不是添加：
BackgroundWorker worker = new BackgroundWorker();
worker.DoWork += delegate
{
Dispatcher.BeginInvoke(new Action(delegate { waitWindow.ShowDialog(); }));
DataLoader dataLoader = new DataLoader();
dataLoader.DataLoaded += delegate
{
Dispatcher.BeginInvoke(new Action(delegate() { waitWindow.Close(); }));
};
dataLoader.LoadData();
};
worker.RunWorkerAsync();
...或者如果您只是将数据加载代码复制到此方法中并添加：
BackgroundWorker worker = new BackgroundWorker();
worker.DoWork += delegate
{
Dispatcher.BeginInvoke(new Action(delegate { waitWindow.ShowDialog(); }));
//do dataloading here
Dispatcher.BeginInvoke(new Action(delegate() { waitWindow.Close(); }));
};
worker.RunWorkerAsync();
public class Loader<TFuncResult,TFirstArgType>:FrameworkElement
{
private Func<TFirstArgType,TFuncResult> _execute;
public TFuncResult Result { get; private set; }
public delegate void OnJobFinished(object sender, TFuncResult result);
public event OnJobFinished JobFinished;
public Loader(Func<TFirstArgType,TFuncResult> execute)
{
if (execute == null)
throw new ArgumentNullException("execute");
_execute = execute;
}
private Window GetWaitWindow()
{
Window waitWindow = new Window { Height = 100, Width = 200, WindowStartupLocation = WindowStartupLocation.CenterScreen, WindowStyle = WindowStyle.None };
waitWindow.Content = new TextBlock { Text = "Please Wait", FontSize = 30, FontWeight = FontWeights.Bold, HorizontalAlignment = HorizontalAlignment.Center, VerticalAlignment = VerticalAlignment.Center };
return waitWindow;
}
public void Load(TFirstArgType firstarg, Window waitWindow = null)
{
if (waitWindow == null)
{
waitWindow = GetWaitWindow();
}
BackgroundWorker worker = new BackgroundWorker();
worker.DoWork += delegate
{
Dispatcher.BeginInvoke(new Action(delegate { waitWindow.ShowDialog(); }));
Result = _execute(firstarg);
Dispatcher.BeginInvoke(new Action(delegate() { waitWindow.Close(); }));
};
worker.RunWorkerCompleted += delegate
{
worker.Dispose();
if (JobFinished != null)
{
JobFinished(this, Result);
}
};
worker.RunWorkerAsync();
}
}
编辑2：如何使用它：
假设您的GenerateList()返回类型为List<Donnees>的数据，且类型为int类型的参数（适用于所有类型）：
将其放在要加载数据的位置（例如，在Window_Loaded-Event中）：
Loader<List<Donnees>, int> loader = new Loader<List<Donnees>, int>(GenerateList);
loader.JobFinished += new Loader<List<Donnees>, int>.OnJobFinished(loader_JobFinished);
loader.Load((int)slider.Value);
现在在Code-Behind中调用此EventHandler：
void loader_JobFinished(object sender, List<Donnees> result)
{
YourDataGrid.DataSource = result
}