当枢轴选择更改时，如何在枢轴项目中加载图像后加载音频文件

Question

最近，我尝试为 windows phone 平台创建名为“Learn ABCD”的应用程序。

这个应用程序的主要逻辑是，最初我想在枢轴项目中加载所有字母字符图像，如苹果的 A、球的 B 等图像，并且在滑动每个枢轴项目时，相应的字母图像和音频文件将显示如下如果我滑动到 B 表示球图像和 B 语音文件对应的 B 应该在后台播放。

当使用枢轴控件滑动时，我已成功加载图像并播放了相应的音频文件，但问题是在图像显示给用户之前播放了音频文件。我需要的是在图像之后播放音频文件。

这是我在 Pivot 控件中加载图像的代码：

---

XAML 代码

<phone:Pivot  x:Name="pivot" ItemsSource="{Binding}" SelectionChanged="pivot_SelectionChanged"  >
    <phone:Pivot.HeaderTemplate>
        <DataTemplate>
            <TextBlock Name="HeaderText" Text="" Foreground="White" ></TextBlock>
        </DataTemplate>
    </phone:Pivot.HeaderTemplate>
    <phone:Pivot.ItemTemplate>
        <DataTemplate>
            <Grid Margin="0,-50,0,0">
                <Image  Name="img" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" Source="{Binding _images}" />
            </Grid>
        </DataTemplate>
    </phone:Pivot.ItemTemplate>
</phone:Pivot>

---

我的 CS 文件是

   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 LearnABCD.Resources;
   using System.Windows.Media;
   using System.Windows.Media.Imaging;
   using System.Diagnostics;
   using Microsoft.Xna.Framework.Media;
   using System.Threading;

   namespace LearnABCD
   {
       public partial class MainPage : PhoneApplicationPage
       {

    String[] HeadText = new String[] { "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z" };
    String[] alpha = new String[] { "aa", "bb", "cc", "dd", "ee", "ff", "gg", "hh", "ii", "jj", "kk", "ll", "mm", "nn", "oo", "pp", "qq", "rr", "ss", "tt", "uu", "vv", "ww", "xx", "yy", "zz" };
    String[] Galtones1 = { "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7", "a8", "a9", "a10", "a11", "a12", "a13", "a14", "a15", "a16", "a17", "a18", "a19", "a20", "a21", "a22", "a23", "a24", "a25" };
    String[] Galtones2 = { "aa0", "aa1", "aa2", "aa3", "aa4", "aa5", "aa6", "aa7", "aa8", "aa9", "aa10", "aa11", "aa12", "aa13", "aa14", "aa15", "aa16", "aa17", "aa18", "aa19", "aa20", "aa21", "aa22", "aa23", "aa24", "aa25" };
    private List<TList> _pivotList;
    // Constructor
    public MainPage()
    {
        InitializeComponent();
        Loaded += Pivot_Loaded;
    }
    private void Pivot_Loaded(object sender, RoutedEventArgs e)
    {
        _pivotList = new List<TList>();
        for (int i = 0; i < alpha.Length; i++)
        {
            _pivotList.Add(new TList
            {
                _images = "image/" + alpha[i] + ".png",
            });
        }
        pivot.DataContext = _pivotList;
    }

    private void initialize_audio()
    {
        int noteID1 = pivot.SelectedIndex;
        for (int i = 0; i < 3; i++)
        {
            if (i == 0)
            {
                Initialize();
                Song song = Song.FromUri("Petzold", new Uri("AudioABCD/" + Galtones1[noteID1] + ".mp3", UriKind.Relative));
                PlaySong(song);
            }
            else if (i == 1)
            {
                Initialize();
                Song song = Song.FromUri("Petzold", new Uri("image/fr.mp3", UriKind.Relative));
                PlaySong(song);
            }
            else if (i == 2)
            {
                Initialize();
                Song song = Song.FromUri("Petzold", new Uri("AudioABCD/" + Galtones2[noteID1] + ".mp3", UriKind.Relative));
                PlaySong(song);
            }
            Thread.Sleep(1000);
        }
    }

    private void pivot_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        initialize_audio();
    }

    void Initialize()
    {
        MediaPlayer.Stop();
    }

    void PlaySong(Song song)
    {
        MediaPlayer.Play(song);
    }        
}

class TList
{
    public string _images { get; set; }
}

   }

Answer 1

使用Image 的Loaded 事件来触发您的声音。 即

<Image Loaded="OnImageLoaded"/>

然后在你的 .cs 文件中：

public void OnImageLoaded(object sender, EventArgs e)
{
    PlaySong(song);
}