在没给大家讲解wpf mwm示例之前先给大家简单说下MVVM理论知识:
WPF技术的主要特点是数据驱动UI,所以在使用WPF技术开发的过程中是以数据为核心的,WPF提供了数据绑定机制,当数据发生变化时,WPF会自动发出通知去更新UI。
我们使用模式,一般是想达到高内聚低耦合。在WPF开发中,经典的编程模式是MVVM,是为WPF量身定做的模式,该模式充分利用了WPF的数据绑定机制,最大限度地降低了Xmal文件和CS文件的耦合度,也就是UI显示和逻辑代码的耦合度,如需要更换界面时,逻辑代码修改很少,甚至不用修改。与WinForm开发相比,我们一般在后置代码中会使用控件的名字来操作控件的属性来更新UI,而在WPF中通常是通过数据绑定来更新UI;在响应用户操作上,WinForm是通过控件的事件来处理,而WPF可以使用命令绑定的方式来处理,耦合度将降低。
首先MVVM设计模式的结构
Views: 由Window/Page/UserControl等构成,通过DataBinding与ViewModels建立关联;
ViewModels:由一组命令,可以绑定的属性,操作逻辑构成;因为View与ViewModel进行了解耦,我们可以对ViewModel进行Unit Test;
Models:可以是实体对象或者Web服务;
下面通过一个简单的例子,来介绍一些WPF MVVM模式。首先项目结构:
DelegateCommand.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using WpfApp13.Commands;namespace WpfApp13.ViewModels
{class MainWindowViewModel:NotificationObject{private double input1;public double Input1{get { return input1; }set{input1 = value;this.RaisePropertyChange("Input1");}}private double input2;public double Input2{get { return input2; }set{input2 = value;this.RaisePropertyChange("Input2");}}private double result;public double Result{get { return result; }set{result = value;this.RaisePropertyChange("Result");}}public DelegateCommand AddCommand { get; set; }public void Add(object parameter){this.Result = this.Input1 + this.Input2;}public MainWindowViewModel(){this.AddCommand = new DelegateCommand();this.AddCommand.ExcuteAction = new Action<object>(this.Add);}}
}
MainWindowViewModel.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using WpfApp13.Commands;namespace WpfApp13.ViewModels
{class MainWindowViewModel:NotificationObject{private double input1;public double Input1{get { return input1; }set{input1 = value;this.RaisePropertyChange("Input1");}}private double input2;public double Input2{get { return input2; }set{input2 = value;this.RaisePropertyChange("Input2");}}private double result;public double Result{get { return result; }set{result = value;this.RaisePropertyChange("Result");}}public DelegateCommand AddCommand { get; set; }public void Add(object parameter){this.Result = this.Input1 + this.Input2;}public MainWindowViewModel(){this.AddCommand = new DelegateCommand();this.AddCommand.ExcuteAction = new Action<object>(this.Add);}}
}
NotificationObject.CS
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;namespace WpfApp13.ViewModels
{class NotificationObject : INotifyPropertyChanged{public event PropertyChangedEventHandler PropertyChanged;public void RaisePropertyChange(string propertyName){if(this.PropertyChanged!=null){this.PropertyChanged.Invoke(this, new PropertyChangedEventArgs(propertyName));}}}
}
MainWindow.xaml.CS
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using WpfApp13.ViewModels;namespace WpfApp13
{/// <summary>/// MainWindow.xaml 的交互逻辑/// </summary>public partial class MainWindow : Window{public MainWindow(){InitializeComponent();this.DataContext = new MainWindowViewModel();}}}
MainWindow.xaml
<Window x:Class="WpfApp13.MainWindow"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:d="http://schemas.microsoft.com/expression/blend/2008"xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"xmlns:local="clr-namespace:WpfApp13"mc:Ignorable="d"Title="MainWindow" Height="450" Width="800"><Grid><StackPanel><Slider Name="slider1" MinHeight="25" Value="{Binding Input1}"/><Slider Name="slider2" MinHeight="25" Value="{Binding Input2}"/><Slider Name="slider3" MinHeight="25" Value="{Binding Result}"/><Button Name="addButton" Content="ADD" FontSize="30" MinHeight="40" Command="{Binding AddCommand}"/></StackPanel> </Grid>
</Window>
运行效果:
分别拖动滑块slider1和slider2,点击按钮后slider3就会自动变化
百度网盘源码下载地址:
链接:https://pan.baidu.com/s/1AvBncokY8SiW0fd9XqrPRw
提取码:ttpo
技术群: 需要进技术群学习交流的请添加小编微信,切记备注:加群,对以上内容有什么疑问也可以直接和小编直接沟通交流!
小编微信:mm1552923
公众号:dotNet编程大全