如何：將快取的項目當做筆刷使用

使用 類別 BitmapCacheBrush 有效率地重複使用快取的專案。 若要快取專案，請建立 類別的新實例 BitmapCache ，並將它指派給元素的 CacheMode 屬性。

範例

下列程式碼範例示範如何重複使用快取的專案。 快取的專案是 Image 顯示大型影像的控制項。 控制項 Image 會使用 BitmapCache 類別快取為點陣圖，而快取則是藉由將它指派給 BitmapCacheBrush 來重複使用。 筆刷會指派給 25 個按鈕的背景，以顯示有效率的重複使用。

<Window x:Class="BitmapCacheBrushDemo.Window1"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Window1"  
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
        Height="300" Width="300" >
    <Window.Resources>
        <RichTextBox x:Key="cachedRichTextBox"  >
            <RichTextBox.CacheMode>
                <BitmapCache EnableClearType="True" RenderAtScale="1" SnapsToDevicePixels="True" />
            </RichTextBox.CacheMode>
        </RichTextBox>

        <BitmapCacheBrush x:Key="cachedRichTextBoxBrush" Target="{StaticResource cachedRichTextBox}">
            <BitmapCacheBrush.BitmapCache>
                <BitmapCache EnableClearType="False" RenderAtScale="0.4" SnapsToDevicePixels="False" />
            </BitmapCacheBrush.BitmapCache>
        </BitmapCacheBrush>        
    </Window.Resources>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="*" />
            <RowDefinition Height="*" />
            <RowDefinition Height="*" />
            <RowDefinition Height="*" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Name="button1" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Name="button2" Grid.Column="1" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Name="button3" Grid.Column="2" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Name="button4" Grid.Column="3" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Name="button5" Grid.Column="4" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Name="button6" Grid.Row="1" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Grid.Column="1" Name="button7" Grid.Row="1" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Grid.Column="2" Name="button8" Grid.Row="1" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Grid.Column="3" Name="button9" Grid.Row="1" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Grid.Column="4" Name="button10" Grid.Row="1" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Name="button11" Grid.Row="2" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Grid.Column="1" Name="button12" Grid.Row="2" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Grid.Column="2" Name="button13" Grid.Row="2" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Grid.Column="3" Name="button14" Grid.Row="2" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Grid.Column="4" Name="button15" Grid.Row="2" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Name="button16" Grid.Row="3" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Grid.Column="1" Name="button17" Grid.Row="3" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Grid.Column="2" Name="button18" Grid.Row="3" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Grid.Column="3" Name="button19" Grid.Row="3" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Grid.Column="4" Name="button20" Grid.Row="3" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Name="button21" Grid.Row="4" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Grid.Column="1" Name="button22" Grid.Row="4" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Grid.Column="2" Name="button23" Grid.Row="4" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Grid.Column="3" Name="button24" Grid.Row="4" FontWeight="Bold" />
        <Button Background="{StaticResource cachedRichTextBoxBrush}" Content="Button" Grid.Column="4" Name="button25" Grid.Row="4" FontWeight="Bold" />
    </Grid>
</Window>

另請參閱

• BitmapCache
• BitmapCacheBrush
• CacheMode
• 操作說明：透過快取元素改善轉譯效能