複用動態創建的視圖

Question

我動態創建說，在環300點的觀點：

例：

for (int j = 0; j <= 300; j++) 
{ 
    Image image = new Image(); 
    image.Source = new BitmapImage(new Uri("/Images/sample256.png", UriKind.RelativeOrAbsolute)); 

    Grid titleGrid = new Grid(); 
    titleGrid.HorizontalAlignment = HorizontalAlignment.Center; 
    titleGrid.VerticalAlignment = VerticalAlignment.Center; 

    TextBlock titleText = new TextBlock(); 
    titleText.TextWrapping = TextWrapping.Wrap; 
    titleGrid.Children.Add(titleText); 

    Grid subtitleGrid = new Grid(); 
    subtitleGrid.HorizontalAlignment = HorizontalAlignment.Center; 
    subtitleGrid.VerticalAlignment = VerticalAlignment.Center; 

    TextBlock subtitleText = new TextBlock(); 
    subtitleText.TextWrapping = TextWrapping.Wrap; 

    subtitleGrid.Children.Add(subtitleText); 

    //add all views to root layout 
    LayoutRoot.Children.Add(image); 
    LayoutRoot.Children.Add(titleGrid); 
    LayoutRoot.Children.Add(subtitleGrid); 
} 

現在有在應用滯後，因爲我每次增加新的看法，怎麼能我重用已經創建的視圖？我正在開發Windows Phone 8應用程序。

Answer 1

您可以嘗試使用DataBinding功能而不是創建此功能。

// You can bound items from your Class here 

<ListBox x:Name="ListBox1" Margin="5" 
Width="450" Height="200" HorizontalAlignment="Left" 
ItemsSource="{Binding SongsList}"> 
ListBox.ItemsPanel> 
      <ItemsPanelTemplate> 
       <VirtualizingStackPanel CleanUpVirtualizedItemEvent="VirtualizingStackPanel_CleanUpVirtualizedItemEvent_1"> 
       </VirtualizingStackPanel> 
      </ItemsPanelTemplate> 

<ListBox.ItemTemplate> 
    <DataTemplate> 
     <StackPanel Orientation="Horizontal" Margin="2"> 
     <TextBlock Text="Artist:" Margin="2" /> 
     <TextBlock Text="{Binding Artist}" Margin="2" /> 
     <TextBlock Text="CD:" Margin="10,2,0,2" /> 
     <TextBlock Text="{Binding Name}" Margin="2" /> 
    </StackPanel> 
    </DataTemplate> 
</ListBox.ItemTemplate> 

// your class should be like this 
public Songs 
{ 
public string Artist{get;set;} 
public string Name {get;set;} 
} 

//代碼隱藏僅僅添加數據

ObservableCollection<Songs> SongsList=new ObservableCollection<SongsL(); 

for (int j = 0; j <= 300; j++) 
{ 
    SongsList.Add(new Songs{Artist="Aritst Name",Name="Song Name"}); 
} 

// Set this Collection from the codebehind or xaml . 
ListBox1.ItemSource=SongsList; // it will the bind the public properties in this Songs. 

DataBinding Controls on Windows phone

Msdn Databindin greference

Binding data Grid

Databinding from Jesse Liberty

Answer 2

添加布局根300項將definatly使頁面加載緩慢。您需要使用實現像列表框這樣的虛擬化的控件。這裏是如何在你的頁面上使用ListBox XAML。

<ListBox Name="myListBox" ItemsSource="{Binding}"> 
      <ListBox.ItemTemplate> 
       <DataTemplate> 
        <StackPanel Orientation="Vertical"> 
         <Image Source="{Binding ImageUrl}"> 
         </Image> 
         <TextBlock Text="{Binding Question}"></TextBlock> 
         <TextBlock Text="{Binding Answer}"></TextBlock> 
        </StackPanel> 
       </DataTemplate> 
      </ListBox.ItemTemplate> 
     </ListBox> 

後面的代碼

code to bind data 

    List<MyData> list = new List<MyData>(); 
     for (int i = 0; i < 300; i++) 
     { 
      var data = new MyData(); 
      data.Question = "//yourquestion"; 
      data.Answer = "// your answer"; 
      data.ImageSource = new BitmapImage(new Uri("yourimagepat")); 
     } 
     myListBox.ItemsSource = list; 

數據類

public class MyData { 
    public string Question { get; set; } 

    public string Answer { get; set; } 

    public BitmapImage ImageSource { get; set; } 
} 

採取虛擬化的優勢，請加在電網控制你的列表框。否則它可以拋出內存異常，也將是緩慢的