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WPF中使用VisualBrush的实例
本文实现一个名为“你来我往”的小程序,该程序管理着“张三”和“李四”两位童鞋拥有的现金,一开始,两人均拥有100美元的现金,随着将现金从其中一人转移至另外一人,两人拥有的现金数在不断变化,程序可以跟踪这种变化,并正确显示每人拥有的现金数。每次最多可以转移三张纸币,纸币的金额可以是5美元、10美元或者20美元。
程序运行后的效果如图1所示,我们点击“张三”右边的“5美元”“10美元”“20美元”按钮,再点击“Play”按钮,便完成了现金从“张三”向“李四”流动,流动后,“张三”拥有的现金变为135美元,而“李四”仅剩下65美元,运行后的效果如图2所示。
图1 初始状态图
图2 现金流动后的分布图
在点击“张三”右边的“5美元”“10美元”或者“20美元”按钮时,会将“5美元”“10美元”或者“20美元”按钮复制一份进“张三”与“李四”之间的“待支付区”,而完成这个操作就需要使用到VisualBrush。
图3 现金流进待支付区的示意图
点击“Cancel”按钮可以清空“待支付区”中的按钮。
VisualBrush是WPF画刷类Brush的派生类,Brush类是个抽象类,WPF中派生自Brush类的还有:SolidColorBrush(实心画刷)、LinearGradientBrush(线性渐变画刷)、RadialGradientBrush(径向渐变画刷)、ImageBrush、DrawingBrush等。VisualBrush使用Visual对象来绘制区域,Visual对象包括Button、Page等。本例中使用VisualBrush来绘制Rectangle的Fill,最终达到的效果就是将按钮复制进“待支付区”。这部分操作的代码如下所示。
private void AddChildren(Button btn) { VisualBrush vBrush = new VisualBrush(btn); Rectangle rect = new Rectangle(); rect.Width = btn.ActualWidth; rect.Height = btn.ActualHeight; rect.Fill = vBrush; rect.Opacity = 0.8; this.StackPanel_Pay.Children.Add(rect); }代码中,使用按钮初始化VisualBrush,接着,按照按钮的宽度和高度绘制矩形,并将矩形的Fill属性设置为VisualBrush对象,最后将新绘制的矩形添加进“待支付区”。 好了,就到这里了。
下面附上本例的完整代码。
MainWindow.xaml文件代码
<Window x:Class="WpfVisualBrushExp.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="你来我往" Height="350" Width="525" WindowStyle="ToolWindow"> <Grid> <Grid.RowDefinitions> <RowDefinition Height="*"></RowDefinition> <RowDefinition Height="*"></RowDefinition> <RowDefinition Height="*"></RowDefinition> <RowDefinition Height="0.2*"></RowDefinition> <RowDefinition Height="*"></RowDefinition> <RowDefinition Height="0.2*"></RowDefinition> <RowDefinition Height="*"></RowDefinition> <RowDefinition Height="*"></RowDefinition> <RowDefinition Height="*"></RowDefinition> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="*"></ColumnDefinition> <ColumnDefinition Width="*"></ColumnDefinition> <ColumnDefinition Width="*"></ColumnDefinition> <ColumnDefinition Width="0.05*"></ColumnDefinition> <ColumnDefinition Width="*"></ColumnDefinition> </Grid.ColumnDefinitions> <TextBlock Text="张三拥有" Grid.Row="1" Grid.Column="0" HorizontalAlignment="Right" Margin="0,10,0,10" /> <TextBlock x:Name="TextBlock_ZhangsanAmount" Grid.Row="1" Grid.Column="1" HorizontalAlignment="Center" Margin="0,10,0,10" /> <TextBlock Text="美元" Grid.Row="1" Grid.Column="2" HorizontalAlignment="Left" Margin="0,10,0,10" /> <Button x:Name="Button_ToLisiFive" Content="5美元" Grid.Row="0" Grid.Column="4" Click="Button_ToLisiFive_Click" /> <Button x:Name="Button_ToLisiTen" Content="10美元" Grid.Row="1" Grid.Column="4" Click="Button_ToLisiTen_Click" /> <Button x:Name="Button_ToLisiTwenty" Content="20美元" Grid.Row="2" Grid.Column="4" Click="Button_ToLisiTwenty_Click" /> <TextBlock Grid.Row="3" Grid.Column="0" Grid.ColumnSpan="5" Background="Cyan"/> <StackPanel x:Name="StackPanel_Pay" Background="White" Grid.Row="4" Grid.Column="0" Grid.ColumnSpan="3" Orientation="Horizontal"/> <StackPanel Grid.Row="4" Grid.Column="4"> <Button x:Name="Button_Pay" Content="Pay" Click="Button_Pay_Click" /> <Button x:Name="Button_Cancel" Content="Cancel" Click="Button_Cancel_Click" /> </StackPanel> <TextBlock Grid.Row="5" Grid.Column="0" Grid.ColumnSpan="5" Background="Cyan"/> <TextBlock Text="李四拥有" Grid.Row="7" Grid.Column="0" HorizontalAlignment="Right" Margin="0,10,0,10" /> <TextBlock x:Name="TextBlock_LisiAmount" Grid.Row="7" Grid.Column="1" HorizontalAlignment="Center" Margin="0,10,0,10" /> <TextBlock Text="美元" Grid.Row="7" Grid.Column="2" HorizontalAlignment="Left" Margin="0,10,0,10" /> <Button x:Name="Button_ToZhangsanFive" Content="5美元" Grid.Row="6" Grid.Column="4" Click="Button_ToZhangsanFive_Click" /> <Button x:Name="Button_ToZhangsanTen" Content="10美元" Grid.Row="7" Grid.Column="4" Click="Button_ToZhangsanTen_Click" /> <Button x:Name="Button_ToZhangsanTwenty" Content="20美元" Grid.Row="8" Grid.Column="4" Click="Button_ToZhangsanTwenty_Click" /> <TextBlock Grid.Row="0" Grid.Column="3" Grid.RowSpan="9" Background="Cyan"/> </Grid> </Window>
MainWindow.xaml.cs文件代码
//************************************************************ // // VisualBrush示例代码 // // Author:三五月儿 // // Date:2014/08/26 // // http://blog.csdn.net/yl2isoft // //************************************************************ using System; using System.Collections.Generic; using System.Linq; using System.Windows; using System.Windows.Controls; using System.Windows.Media; using System.Windows.Shapes; namespace WpfVisualBrushExp { /// <summary> /// MainWindow.xaml 的交互逻辑 /// </summary> public partial class MainWindow : Window { bool isZhangsanPaying = false; bool isLisiPaying = false; List<int> zhangsanPayAmountList = new List<int>(); List<int> lisiPayAmountList = new List<int>(); public MainWindow() { InitializeComponent(); this.TextBlock_ZhangsanAmount.Text = "100"; this.TextBlock_LisiAmount.Text = "100"; } #region 张三 private void Button_ToLisiFive_Click(object sender, RoutedEventArgs e) { if (ReturnByMaxCount() || ReturnByLisiIsPaying()) { return; } AddChildren(this.Button_ToLisiFive); zhangsanPayAmountList.Add(5); isZhangsanPaying = true; } private void Button_ToLisiTen_Click(object sender, RoutedEventArgs e) { if (ReturnByMaxCount() || ReturnByLisiIsPaying()) { return; } AddChildren(this.Button_ToLisiTen); zhangsanPayAmountList.Add(10); isZhangsanPaying = true; } private void Button_ToLisiTwenty_Click(object sender, RoutedEventArgs e) { if (ReturnByMaxCount() || ReturnByLisiIsPaying()) { return; } AddChildren(this.Button_ToLisiTwenty); zhangsanPayAmountList.Add(20); isZhangsanPaying = true; } #endregion //张三 #region 李四 private void Button_ToZhangsanFive_Click(object sender, RoutedEventArgs e) { if (ReturnByMaxCount() || ReturnByZhangsanIsPaying()) { return; } AddChildren(this.Button_ToZhangsanFive); lisiPayAmountList.Add(5); isLisiPaying = true; } private void Button_ToZhangsanTen_Click(object sender, RoutedEventArgs e) { if (ReturnByMaxCount() || ReturnByZhangsanIsPaying()) { return; } AddChildren(this.Button_ToZhangsanTen); lisiPayAmountList.Add(10); isLisiPaying = true; } private void Button_ToZhangsanTwenty_Click(object sender, RoutedEventArgs e) { if (ReturnByMaxCount() || ReturnByZhangsanIsPaying()) { return; } AddChildren(this.Button_ToZhangsanTwenty); lisiPayAmountList.Add(20); isLisiPaying = true; } #endregion //李四 private bool ReturnByMaxCount() { if (this.StackPanel_Pay.Children.Count >= 3) { MessageBox.Show("一次最多只能支付3张美元。"); return true; } return false; } private bool ReturnByZhangsanIsPaying() { if (isZhangsanPaying == true) { MessageBox.Show("张三正在支付中..."); return true; } return false; } private bool ReturnByLisiIsPaying() { if (isLisiPaying == true) { MessageBox.Show("李四正在支付中..."); return true; } return false; } private void AddChildren(Button btn) { VisualBrush vBrush = new VisualBrush(btn); Rectangle rect = new Rectangle(); rect.Width = btn.ActualWidth; rect.Height = btn.ActualHeight; rect.Fill = vBrush; rect.Opacity = 0.8; this.StackPanel_Pay.Children.Add(rect); } private void Button_Pay_Click(object sender, RoutedEventArgs e) { if (isZhangsanPaying) { int zhangsanAmount = Convert.ToInt32(this.TextBlock_ZhangsanAmount.Text) - zhangsanPayAmountList.Sum(it => it); int lisiAmount = Convert.ToInt32(this.TextBlock_LisiAmount.Text) + zhangsanPayAmountList.Sum(it => it); this.TextBlock_ZhangsanAmount.Text = zhangsanAmount.ToString(); this.TextBlock_LisiAmount.Text = lisiAmount.ToString(); zhangsanPayAmountList.Clear(); isZhangsanPaying = false; } else { int lisiAmount = Convert.ToInt32(this.TextBlock_LisiAmount.Text) - lisiPayAmountList.Sum(it => it); int zhangsanAmount = Convert.ToInt32(this.TextBlock_ZhangsanAmount.Text) + lisiPayAmountList.Sum(it => it); this.TextBlock_LisiAmount.Text = lisiAmount.ToString(); this.TextBlock_ZhangsanAmount.Text = zhangsanAmount.ToString(); lisiPayAmountList.Clear(); isLisiPaying = false; } this.StackPanel_Pay.Children.Clear(); } private void Button_Cancel_Click(object sender, RoutedEventArgs e) { this.StackPanel_Pay.Children.Clear(); zhangsanPayAmountList.Clear(); lisiPayAmountList.Clear(); isZhangsanPaying = false; isLisiPaying = false; } } }
WPF中使用VisualBrush的实例