Silverlight学习笔记二(页面跳转与控件拖动效果实现)

接笔记一：http://www.cnblogs.com/greatverve/archive/2010/05/09/1731164.html
web上面最常见的就是从一个页面跳转到另一个页面，搜索了一下，原来Silverlight是这样实现页面跳转的。
一、新建一个接口，代码如下：

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace FirstSilverlight
{
    public interface IContent
    {
        UIElement Content { get; set; }
    }
}

 

新建一个Silverlight用户控件，代码如下：

<UserControl xmlns:basics="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls"  x:Class="FirstSilverlight.FirstControl"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    Width="400" Height="300">
    <Grid x:Name="LayoutRoot" Background="White">
    <Button Width="100" Height="50" Name="btnGo" Content="跳转" Click="Button_Click"></Button>
    </Grid>
</UserControl>

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace FirstSilverlight
{
    public partial class FirstControl : UserControl, IContent//继承接口
    {
        public FirstControl()
        {
            InitializeComponent();
        }
        //实现接口
        public new UIElement Content
        {
            get
            {
                return base.Content;
            }
            set
            {
                base.Content = value;
            }
        } 

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            //实现页面跳转
            (Application.Current.RootVisual as IContent).Content = new DragControl();
        }
    }
}

 

另外发现一个小技巧，就好像WinForm的Main()函数里设置第一个窗口一样Application.Run(new MainForm());
在App.xaml.cs的Application_Startup()可以设置第一个场景，代码如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace FirstSilverlight
{
    public partial class App : Application
    {

        public App()
        {
            this.Startup += this.Application_Startup;
            this.Exit += this.Application_Exit;
            this.UnhandledException += this.Application_UnhandledException;

            InitializeComponent();
        }

        private void Application_Startup(object sender, StartupEventArgs e)
        {
            //this.RootVisual = new Page();
            this.RootVisual = new FirstControl();//设置第一个场景
        }

        private void Application_Exit(object sender, EventArgs e)
        {

        }
        private void Application_UnhandledException(object sender, ApplicationUnhandledExceptionEventArgs e)
        {
            // 如果应用程序是在调试器外运行的，则使用浏览器的
            // 异常机制报告该异常。在 IE 上，将在状态栏中用一个 
            // 黄色警报图标来显示该异常，而 Firefox 则会显示一个脚本错误。
            if (!System.Diagnostics.Debugger.IsAttached)
            {

                // 注意: 这使应用程序可以在已引发异常但尚未处理该异常的情况下
                // 继续运行。 
                // 对于生产应用程序，此错误处理应替换为向网站报告错误
                // 并停止应用程序。
                e.Handled = true;
                Deployment.Current.Dispatcher.BeginInvoke(delegate { ReportErrorToDOM(e); });
            }
        }
        private void ReportErrorToDOM(ApplicationUnhandledExceptionEventArgs e)
        {
            try
            {
                string errorMsg = e.ExceptionObject.Message + e.ExceptionObject.StackTrace;
                errorMsg = errorMsg.Replace('"', '\'').Replace("\r\n", @"\n");

                System.Windows.Browser.HtmlPage.Window.Eval("throw new Error(\"Unhandled Error in Silverlight 2 Application " + errorMsg + "\");");
            }
            catch (Exception)
            {
            }
        }
    }
}

 

现在是拖动效果的实现，新建Silverlight用户控件DragControl.xaml

<UserControl x:Class="FirstSilverlight.DragControl"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    Width="400" Height="300">
    <Canvas Background="#46461F">
        <!--李会军这里用Button已经无法拖动-->
        <Image Source="smile_6.png" 
        MouseLeftButtonDown="OnMouseDown" 
        MouseMove="OnMouseMove" 
        MouseLeftButtonUp="OnMouseUp"/>
    </Canvas>
</UserControl>

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace FirstSilverlight
{
    public partial class DragControl : UserControl
    {
        public DragControl()
        {
            InitializeComponent();
        }
        
        bool trackingMouseMove = false;
        Point mousePosition;

        void OnMouseDown(object sender, MouseButtonEventArgs e)
        {
            FrameworkElement element = sender as FrameworkElement;
            mousePosition = e.GetPosition(null);
            trackingMouseMove = true;
            if (null != element)
            {
                element.CaptureMouse();
                element.Cursor = Cursors.Hand;
            }
        }
        void OnMouseMove(object sender, MouseEventArgs e)
        {
            FrameworkElement element = sender as FrameworkElement;
            if (trackingMouseMove)
            {
                double deltaV = e.GetPosition(null).Y - mousePosition.Y;
                double deltaH = e.GetPosition(null).X - mousePosition.X;
                double newTop = deltaV + (double)element.GetValue(Canvas.TopProperty);
                double newLeft = deltaH + (double)element.GetValue(Canvas.LeftProperty);

                element.SetValue(Canvas.TopProperty, newTop);
                element.SetValue(Canvas.LeftProperty, newLeft);

                mousePosition = e.GetPosition(null);
            }
        }
        void OnMouseUp(object sender, MouseButtonEventArgs e)
        {
            FrameworkElement element = sender as FrameworkElement;
            trackingMouseMove = false;
            element.ReleaseMouseCapture();

            mousePosition.X = mousePosition.Y = 0;
            element.Cursor = null;
        }
    }
}

 

有空就积累一点吧，欢迎大家指点。