干掉MessageBox，自定义弹出框JMessbox (WindowsPhone)

先上效果图

QQ退出效果小弟控件效果图

首先分析一下页面结构，QQ图中弹出框的组成：透明背景，文字背景，文字颜色

在wp上，小弟分别采用Popup控件，用户控件（透明背景，文字背景用Border,显示文字用BlockText）

不想卖关子，直接上代码解析

哦，这里要说一下，这个类库结构，Resource只要放资源文件，系统编译时候会自动编译进去dll里头

1、用户控件UI代码，很简单吧，主要注意一下Border设置一下CornerRadius圆角属性

<UserControl x:Class="JM.Phone.Control.JMessboxControl"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    d:DesignHeight="480" d:DesignWidth="480">
 
    <Grid x:Name="LayoutRoot" Width="480" Height="800">
        <Grid.Background>
            <ImageBrush x:Name="layoutRootImage" ImageSource="/JM.Control;component/Resource/bg_transparent.png"></ImageBrush>
        </Grid.Background>
        <Border Height="65" Width="200" CornerRadius="2">
            <Border.Background>
                <ImageBrush x:Name="textImage" ImageSource="/JM.Control;component/Resource/bg_tips.png"></ImageBrush>
            </Border.Background>
            <TextBlock Text="再按一次离开" FontSize="24" Height="35" TextAlignment="Center" Foreground="White"></TextBlock>
        </Border>
    </Grid>
</UserControl>

2、用户控件后台代码也很简单，定义2个属性，方便以后扩展。。这里只能设置本地图片。。当然你也可以拿到源代码后，自己修改为网络路径图片

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Navigation;
using Microsoft.Phone.Controls;
using Microsoft.Phone.Shell;
using System.Windows.Media;
using System.Windows.Media.Imaging;
 
namespace JM.Phone.Control
{
    public partial class JMessboxControl : UserControl
    {
        /// <summary>
        /// popup背景图片
        /// </summary>
        private string _layoutRootImage = "/JM.Phone.Control;component/Resource/bg_transparent.png";
        public string LayoutRootImage
        {
            get { return _layoutRootImage; }
            set { _layoutRootImage = value; }
        }
 
        /// <summary>
        /// 文本背景
        /// </summary>
        private string _textImage = "/JM.Phone.Control;component/Resource/bg_tips.png";
        public string TextImage
        {
            get { return _textImage; }
            set { _textImage = value; }
        }
 
        public JMessboxControl()
        {
            InitializeComponent();
            this.Loaded += JTipsControl_Loaded;
        }
 
        void JTipsControl_Loaded(object sender, RoutedEventArgs e)
        {
            layoutRootImage.ImageSource = SetSource(LayoutRootImage);
            textImage.ImageSource = SetSource(TextImage);
        }
 
        /// <summary>
        /// 设置图片路径 （针对相对路径uri）
        /// </summary>
        /// <param name="uri"></param>
        /// <returns></returns>
        public  ImageSource SetSource(string uri, UriKind rk = UriKind.Relative)
        {
            BitmapImage bit = new BitmapImage();
            bit.UriSource = new Uri(uri, rk);
            return bit;
        }
    }
}

3、调用方式在页面重写OnBackKeyPress方法，注意要引用这个控件dll

int clickCount = 0;
        protected override void OnBackKeyPress(System.ComponentModel.CancelEventArgs e)
        {
            e.Cancel = true;

            //2s之内连续按2次，退出
            if (clickCount > 0)
            {
                //WP7退出代码（一般采用抛出异常退出）
                //throw new Exception();

                //WP8退出代码,用此行代码，请将项目升级8.0项目
                //Application.Current.Terminate()

            }

            clickCount++;
            var tips = new JMessboxControl();
            popup.Height = 800;
            popup.Width = 480;
            popup.IsOpen = false;
            popup.Child = tips;

            Storyboard story = new Storyboard();
            DoubleAnimation topAnimation = new DoubleAnimation();
            topAnimation.From = 0;
            topAnimation.To = 1;
            Storyboard.SetTarget(topAnimation, tips);
            Storyboard.SetTargetProperty(topAnimation, new PropertyPath("(UIElement.Opacity)"));
            popup.IsOpen = true;
            story.Begin();
            story.Duration = new Duration(new TimeSpan(0, 0, 2));
            story.Completed += (s1, e1) =>
            {
                //2s后执行此方法
                clickCount = 0;
                popup.IsOpen = false;
                story.Stop();
            };

            base.OnBackKeyPress(e);
        }

里面大概原理：

1、如果用户在2s之内点击后退按钮2次，就当做是退出。。。

2、用一个动画显示此控件出来，动画2s运行完后，执行Completed ，清除计数器并关闭Popup（这里也可以制作一个渐变隐藏动画，小弟偷懒，就不贴代码）

用着这个控件，顿时感觉我程序高端大气上档次啦

顿时想法，改进之后代码

4、定义一个类，这个类主要作用给页面调用

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls.Primitives;
using System.Windows.Media.Animation;

namespace JM.Phone.Control
{
    public class JMessBox
    {
        public Action<bool> Completed;

        Popup popup = new Popup();
        //这里定义个静态变量，避免每次初始化都变为0
        //静态变量，个人理解，只会初始化一次
        static int clickCount = 0;
        public void Show()
        {
            //2s之内连续按2次，退出
            if (clickCount > 0)
            {
                if (Completed != null)
                {
                    Completed(true);
                }
            }
            else
            {

                clickCount++;

                if (Completed != null)
                {
                    Completed(false);
                }

                var tips = new JMessboxControl();
                popup.Height = 65;
                popup.Width = 200;
                popup.Margin = new Thickness(140, 380, 0, 0);
                popup.IsOpen = false;
                popup.Child = tips;

                //渐变效果:透明度200毫秒内从0->1
                Storyboard story = new Storyboard();
                DoubleAnimation topAnimation = new DoubleAnimation();
                topAnimation.From = 0;
                topAnimation.To = 1;
                topAnimation.Duration = new Duration(TimeSpan.FromMilliseconds(200));
                Storyboard.SetTarget(topAnimation, tips);
                Storyboard.SetTargetProperty(topAnimation, new PropertyPath("(UIElement.Opacity)"));

                story.Children.Add(topAnimation);

                popup.IsOpen = true;
                story.Begin();
                //动画延迟2秒
                story.Duration = new Duration(new TimeSpan(0, 0, 2));
                //story.BeginTime = new TimeSpan(0, 0, 0, 0, 1);
                story.Completed += (s1, e1) =>
                {
                    //2s后执行此方法
                    clickCount = 0;
                    popup.IsOpen = false;
                    story.Stop();
                };
            }

        }
    }
}

那么以上第三点改为这样子调用

protected override void OnBackKeyPress(System.ComponentModel.CancelEventArgs e)
   {
            e.Cancel = true;

            JMessBox jb = new JMessBox();
            jb.Completed += (b) =>
            {
                if (b)
                {
                    //WP7退出代码
                    throw new Exception();
                    //WP8退出代码
                }
            };

            jb.Show();
  }