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

Posted 2023-02-25

【中文标题】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

【英文标题】：How to load audio file after image loaded in pivot items when pivot selection changed

【发布时间】：2014-09-24 13:10:40

【问题描述】：

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; 


   

【参考方案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);

【讨论】：

在图像加载第一次加载图像时播放相应的音频..但是如果我反向滑动已经加载图像的音频不应该播放..请解决此错误...

添加布尔列表并设置它们以标记它们已经播放过。