WPF高级用法示例
WPF高级用法示例
一、MVVM模式深度实现
1. 命令模式扩展
// RelayCommand.cs - 支持CanExecuteChanged事件和参数
public class RelayCommand : ICommand
{
private readonly Action2. ViewModel基类
// ViewModelBase.cs - 实现INotifyPropertyChanged和IDisposable
public abstract class ViewModelBase : INotifyPropertyChanged, IDisposable
{
private bool _disposed = false;
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
protected bool SetField(ref T field, T value, [CallerMemberName] string propertyName = null)
{
if (EqualityComparer.Default.Equals(field, value)) return false;
field = value;
OnPropertyChanged(propertyName);
return true;
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
protected virtual void Dispose(bool disposing)
{
if (!_disposed)
{
if (disposing)
{
// 释放托管资源
}
_disposed = true;
}
}
~ViewModelBase() => Dispose(false);
} 3. 异步命令实现
// AsyncRelayCommand.cs - 支持异步操作
public class AsyncRelayCommand : ICommand
{
private readonly Func _execute;
private readonly Predicate 二、高级数据绑定技术
1. 多绑定与转换器
public class FullNameConverter : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
if (values[0] is string firstName && values[1] is string lastName)
return $"{firstName} {lastName}";
return string.Empty;
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}2. 动态数据模板
public class ItemTypeTemplateSelector : DataTemplateSelector
{
public DataTemplate TextTemplate { get; set; }
public DataTemplate ImageTemplate { get; set; }
public override DataTemplate SelectTemplate(object item, DependencyObject container)
{
if (item is TextItem) return TextTemplate;
if (item is ImageItem) return ImageTemplate;
return base.SelectTemplate(item, container);
}
}
三、自定义控件开发
1. 自定义控件基类
// CustomControlBase.cs - 提供通用功能
public abstract class CustomControlBase : Control
{
static CustomControlBase()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(CustomControlBase),
new FrameworkPropertyMetadata(typeof(CustomControlBase)));
}
protected override void OnApplyTemplate()
{
base.OnApplyTemplate();
// 模板应用后的初始化
}
}2. 高级自定义控件示例
// 需要添加的依赖属性
public class AdvancedProgressBar : Control
{
public static readonly DependencyProperty ValueProperty =
DependencyProperty.Register("Value", typeof(double), typeof(AdvancedProgressBar),
new FrameworkPropertyMetadata(0.0, FrameworkPropertyMetadataOptions.AffectsRender));
public double Value
{
get => (double)GetValue(ValueProperty);
set => SetValue(ValueProperty, value);
}
}四、高级动画技术
1. 关键帧动画
private void PlayAnimation_Click(object sender, RoutedEventArgs e)
{
var story = (Storyboard)FindResource("FadeInOut");
story.Begin(this);
}2. 自定义缓动函数
// 自定义缓动函数
public class ElasticEaseConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
if (value is double progress && targetType == typeof(double))
{
// 实现弹性缓动效果
return Math.Sin(progress * Math.PI * (0.2f + 2.5f * progress * progress * progress))
* Math.Pow(1f - progress, 2.2f) + progress;
}
return value;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
五、高级数据可视化
1. 自定义图表控件
2. 高级数据绑定示例
// 转换器实现
public class ComplexConverter : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
if (values[0] is decimal total && values[1] is decimal discount &&
values[2] is string currency)
{
var finalAmount = total - discount;
return $"{currency}{finalAmount:F2}";
}
return "N/A";
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}六、性能优化技术
1. 虚拟化列表
2. 异步数据加载
// ViewModel中的异步数据加载
public class DataViewModel : ViewModelBase
{
private ObservableCollection _items = new ObservableCollection();
public ObservableCollection Items => _items;
public async Task LoadDataAsync()
{
IsLoading = true;
try
{
var data = await DataService.GetDataAsync();
_items.Clear();
foreach (var item in data)
{
_items.Add(item);
}
}
finally
{
IsLoading = false;
}
}
private bool _isLoading;
public bool IsLoading
{
get => _isLoading;
set => SetField(ref _isLoading, value);
}
} 七、高级主题与样式
1. 动态主题切换
// 动态切换主题
public static class ThemeManager
{
public static void ApplyTheme(string themeName)
{
var dict = new ResourceDictionary
{
Source = new Uri($"Themes/{themeName}.xaml", UriKind.Relative)
};
Application.Current.Resources.MergedDictionaries.Clear();
Application.Current.Resources.MergedDictionaries.Add(dict);
}
}2. 自定义控件样式
八、高级布局技术
1. 自定义面板
// 自定义流式面板
public class FlowPanel : Panel
{
public static readonly DependencyProperty OrientationProperty =
DependencyProperty.Register("Orientation", typeof(Orientation), typeof(FlowPanel),
new FrameworkPropertyMetadata(Orientation.Horizontal,
FrameworkPropertyMetadataOptions.AffectsArrange));
public Orientation Orientation
{
get => (Orientation)GetValue(OrientationProperty);
set => SetValue(OrientationProperty, value);
}
protected override Size MeasureOverride(Size availableSize)
{
// 测量逻辑...
return base.MeasureOverride(availableSize);
}
protected override Size ArrangeOverride(Size finalSize)
{
// 排列逻辑...
return base.ArrangeOverride(finalSize);
}
}2. 复杂布局示例
九、高级调试技术
1. 可视化树调试
// 获取可视化树结构
public static void PrintVisualTree(DependencyObject parent, int level = 0)
{
var indent = new string(' ', level * 2);
Debug.WriteLine($"{indent}{parent.GetType().Name}");
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(parent); i++)
{
PrintVisualTree(VisualTreeHelper.GetChild(parent, i), level + 1);
}
}
// 使用方法
PrintVisualTree(this); // 从窗口开始打印2. 性能分析工具
True
十、综合应用示例
1. 任务管理器示例
// ViewModel实现
public class TaskManagerViewModel : ViewModelBase
{
private ObservableCollection _processes = new ObservableCollection();
public ObservableCollection Processes => _processes;
private ProcessInfo _selectedProcess;
public ProcessInfo SelectedProcess
{
get => _selectedProcess;
set => SetField(ref _selectedProcess, value);
}
private double _cpuUsage;
public double CpuUsage
{
get => _cpuUsage;
set => SetField(ref _cpuUsage, value);
}
public TaskManagerViewModel()
{
// 启动后台更新
Task.Run(() => UpdateProcessesAsync());
Task.Run(() => UpdateCpuUsageAsync());
}
private async Task UpdateProcessesAsync()
{
while (true)
{
var processes = await System.Diagnostics.Process.GetProcessesAsync();
// 转换为ProcessInfo对象并更新集合
await Application.Current.Dispatcher.InvokeAsync(() =>
{
Processes.Clear();
foreach (var p in processes)
{
Processes.Add(new ProcessInfo(p));
}
});
await Task.Delay(1000);
}
}
private async Task UpdateCpuUsageAsync()
{
// CPU使用率计算逻辑...
}
} 2. 图表控件实现
// 代码后端
public partial class CustomChart : UserControl
{
public static readonly DependencyProperty DataProperty =
DependencyProperty.Register("Data", typeof(ObservableCollection),
typeof(CustomChart), new PropertyMetadata(null, OnDataChanged));
public ObservableCollection Data
{
get => (ObservableCollection)GetValue(DataProperty);
set => SetValue(DataProperty, value);
}
public CustomChart()
{
InitializeComponent();
DataContext = this;
}
private static void OnDataChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (d is CustomChart chart)
{
chart.UpdateChart();
}
}
private void UpdateChart()
{
ChartCanvas.Children.Clear();
if (Data == null || !Data.Any()) return;
var max = Data.Max(d => d.Value);
var width = ChartCanvas.ActualWidth / Math.Max(1, Data.Count);
for (int i = 0; i < Data.Count; i++)
{
var point = Data[i];
var height = (point.Value / max) * ChartCanvas.ActualHeight;
var rect = new Rectangle
{
Width = width - 1,
Height = height,
Fill = point.Color,
Margin = new Thickness(i * width, ChartCanvas.ActualHeight - height, 0, 0)
};
ChartCanvas.Children.Add(rect);
}
}
}
// 数据点类
public class ChartDataPoint
{
public double Value { get; set; }
public Color Color { get; set; }
public ChartDataPoint(double value, Color color)
{
Value = value;
Color = color;
}
} 十一、部署与打包
1. ClickOnce部署
\\Server\Deploy\
http://server/deploy/
1.0.0.0
1.0.0.0
true
Foreground
7
Days
2. MSI打包
# 使用WiX工具创建MSI安装包
# 1. 安装WiX工具集
# 2. 创建.wxs项目文件
# 3. 定义产品特性
十二、未来扩展方向
1. 跨平台支持
// 使用Avalonia实现跨平台UI
public class CrossPlatformWindow : Window
{
public CrossPlatformWindow()
{
// 平台特定初始化
if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
{
// Windows特定设置
}
else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
{
// Linux特定设置
}
}
}2. 云集成
// 集成Azure服务
public class CloudService
{
private readonly HttpClient _client = new HttpClient();
public async Task UploadFileAsync(string filePath)
{
var content = new MultipartFormDataContent();
var fileContent = new ByteArrayContent(File.ReadAllBytes(filePath));
content.Add(fileContent, "file", Path.GetFileName(filePath));
var response = await _client.PostAsync("https://yourapp.azurewebsites.net/api/upload", content);
response.EnsureSuccessStatusCode();
}
}3. AI集成
// 集成ML.NET进行数据分析
public class DataAnalyzer
{
private readonly PredictionEngine _predictionEngine;
public DataAnalyzer()
{
var mlContext = new MLContext();
var pipeline = mlContext.Transforms.Concatenate("Features", "Feature1", "Feature2")
.Append(mlContext.BinaryClassification.Trainers.SdcaLogisticRegression());
var model = pipeline.Fit(mlContext.Data.LoadFromTextFile("data.csv", hasHeader: true));
_predictionEngine = mlContext.Model.CreatePredictionEngine(model);
}
public bool Analyze(InputData data) => _predictionEngine.Predict(data).PredictedLabel;
} 通过以上高级技术和示例代码，您可以构建功能丰富、性能优越的WPF应用程序，并为未来的扩展和维护打下坚实的基础。