Silverlight 中回车键代替 Tab键的类

在Silverlight中，处理回车键代替 Tab比较麻烦，现在本人写了一个类，简单调用就可实现，原理是先扫描父控件下的所有控件，然后设置每个控件的 keyUp事件，最后根据设置的 TabIndex排序。调用示例代码为：

    public partial class TestPage : Page
    {
        public TestPage()
        {
            InitializeComponent();
            base.Loaded += new RoutedEventHandler(TestPage_Loaded);
        }

        void TestPage_Loaded(object sender, RoutedEventArgs e)
        {
            // 设置 回车代 Tab
            new EnterToTab(this);
        }
    }

 

 EnterToTab.cs代码如下：

 

using System;using System.Windows;using System.Windows.Input;using System.Windows.Media;using System.Collections.Generic;using System.Windows.Controls;using System.Windows.Threading;namespace Ktwl.Common.Controls{ public class EnterToTab { private static List<Type> _ctrlTypes = new List<Type>() { typeof(DatePicker), typeof(TextBox), typeof(PasswordBox), typeof(CheckBox), typeof(ComboBox), }; public static void RegisterType(Type type) { if (!_ctrlTypes.Contains(type)) { _ctrlTypes.Add(type); } } public static IEnumerable<T> FindChildren<T>(DependencyObject parent) where T : class { var count = VisualTreeHelper.GetChildrenCount(parent); if (count > 0) { for (var i = 0; i < count; i++) { var child = VisualTreeHelper.GetChild(parent, i); var t = child as T; if (t != null) yield return t; var children = FindChildren<T>(child); foreach (var item in children) yield return item; } } } private UIElement _parent; private List<Control> _controls = new List<Control>(); public EnterToTab(UIElement parent) { _parent = parent; // 如果控件还没有加载完就调用 Associate() 方法,则不能查找到子控件, // 所以用定时器 DispatcherTimer timer = new DispatcherTimer(); timer.Interval = TimeSpan.FromTicks(100); timer.Tick += new EventHandler(Timer_Tick); timer.Start(); } void Timer_Tick(object sender, EventArgs e) { (sender as DispatcherTimer).Stop(); Associate(); } private bool _isAssociating = false; private void Associate() { if (_isAssociating) return; _isAssociating = true; try { // 清除原来关联过的 foreach (var c in _controls) { c.KeyUp -= new KeyEventHandler(Control_KeyUp); } _controls.Clear(); // 获取可以 Tab 的控件并加入到列表中 IEnumerable<Control> originals = EnterToTab.FindChildren<Control>(_parent); foreach (var c in originals) { if (c.IsTabStop && c.Visibility == Visibility.Visible && c.IsEnabled) { var t1 = c.GetType(); foreach (var t2 in _ctrlTypes) { if (t1.IsAssignableFrom(t2)) { c.KeyUp += new KeyEventHandler(Control_KeyUp); _controls.Add(c); break; } } } } // 根据 TabIndex 的原始值排序 _controls.Sort(new TabIndexComparer()); } finally { _isAssociating = false; } } void Control_KeyUp(object sender, KeyEventArgs e) { if ((e.Key == Key.Enter || e.Key == Key.Down) || (e.Key == Key.Up)) { Control source = (sender as Control); int index = _controls.IndexOf(source); if (e.Key == Key.Enter || e.Key == Key.Down) { if (index < _controls.Count - 1) { _controls[index + 1].Focus(); } } else { if (index > 0) { _controls[index - 1].Focus(); } } } } private class TabIndexComparer : IComparer<Control> { public int Compare(Control x, Control y) { if (x == y) { return 0; } if (x.TabIndex <= y.TabIndex) { return -1; } else { return 1; } } } }}