MVVM_WPF
新建立WPF工程：工程名字为Study
1、MainWindow.xaml:
<Window x:Class="Study.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:Study"
Title="MainWindow" Height="350" Width="525">
<Window.DataContext>
<local:StudentViewControl></local:StudentViewControl>
</Window.DataContext>
<Grid>
<Button Content="Button" Height="23" HorizontalAlignment="Left" Margin="38,103,0,0" Name="button1" VerticalAlignment="Top" Width="75" Command="{Binding UpdateStudentName}" />
<TextBox Height="23" HorizontalAlignment="Left" Margin="38,51,0,0" Name="textBox1" VerticalAlignment="Top" Width="120" Text="{Binding StudentName}" />
</Grid>
</Window>
2、Student.cs
public class Student
{
public string studentName { get; set; }
}
3、
public class StudentViewControl : INotifyPropertyChanged
{
private Student _student;
public Student Student
{
get { return _student; }
set { this._student = value; }
}
public StudentViewControl()
{
this._student = new Student();
this.Student.studentName = "jaygj";
}
public string StudentName
{
get
{
return _student.studentName;
}
set
{
this._student.studentName = value;
OnPropertyChanged();
}
}
public void OnPropertyChanged()
{
PropertyChangedEventHandler hander = PropertyChanged;
if (hander != null)
{
PropertyChanged(this, new PropertyChangedEventArgs("StudentName"));
}
}
public event PropertyChangedEventHandler PropertyChanged;
public ICommand UpdateStudentName { get { return new RelayCommand(UpdateStudentNameExecute, null); } }为null在下面的公公类解析中为ture，不多解释。
或者为
public ICommand UpdateStudentName { get { return new RelayCommand(UpdatStudentNameExecute, GetStatus); } }
public void UpdateStudentNameExecute()
{
this.StudentName = "hello world";
}
public bool GetStatus()
{
return true;
}
}
4.公公类：
// Original author - Josh Smith - http://msdn.microsoft.com/en-us/magazine/dd419663.aspx#id0090030
using System;
using System.Diagnostics;
using System.Windows.Input;
namespace MicroMvvm
{
/// <summary>
/// A command whose sole purpose is to relay its functionality to other objects by invoking delegates. The default return value for the CanExecute method is 'true'.
/// </summary>
public class RelayCommand<T> : ICommand
{
#region Declarations
readonly Predicate<T> _canExecute;
readonly Action<T> _execute;
#endregion
#region Constructors
/// <summary>
/// Initializes a new instance of the <see cref="RelayCommand<T>"/> class and the command can always be executed.
/// </summary>
/// <param name="execute">The execution logic.</param>
public RelayCommand(Action<T> execute)
: this(execute, null)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="RelayCommand<T>"/> class.
/// </summary>
/// <param name="execute">The execution logic.</param>
/// <param name="canExecute">The execution status logic.</param>
public RelayCommand(Action<T> execute, Predicate<T> canExecute)
{
if (execute == null)
throw new ArgumentNullException("execute");
_execute = execute;
_canExecute = canExecute;
}
#endregion
#region ICommand Members
public event EventHandler CanExecuteChanged
{
add
{
if (_canExecute != null)
CommandManager.RequerySuggested += value;
}
remove
{
if (_canExecute != null)
CommandManager.RequerySuggested -= value;
}
}
[DebuggerStepThrough]
public Boolean CanExecute(Object parameter)
{
return _canExecute == null ? true : _canExecute((T)parameter);
}
public void Execute(Object parameter)
{
_execute((T)parameter);
}
#endregion
}
/// <summary>
/// A command whose sole purpose is to relay its functionality to other objects by invoking delegates. The default return value for the CanExecute method is 'true'.
/// </summary>
public class RelayCommand : ICommand
{
#region Declarations
readonly Func<Boolean> _canExecute;
readonly Action _execute;
#endregion
#region Constructors
/// <summary>
/// Initializes a new instance of the <see cref="RelayCommand<T>"/> class and the command can always be executed.
/// </summary>
/// <param name="execute">The execution logic.</param>
public RelayCommand(Action execute)
: this(execute, null)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="RelayCommand<T>"/> class.
/// </summary>
/// <param name="execute">The execution logic.</param>
/// <param name="canExecute">The execution status logic.</param>
public RelayCommand(Action execute, Func<Boolean> canExecute)
{
if (execute == null)
throw new ArgumentNullException("execute");
_execute = execute;
_canExecute = canExecute;
}
#endregion
#region ICommand Members
public event EventHandler CanExecuteChanged
{
add
{
if (_canExecute != null)
CommandManager.RequerySuggested += value;
}
remove
{
if (_canExecute != null)
CommandManager.RequerySuggested -= value;
}
}
[DebuggerStepThrough]
public Boolean CanExecute(Object parameter)
{
return _canExecute == null ? true : _canExecute();
}
public void Execute(Object parameter)
{
_execute();
}
#endregion
}
}
以上为自己试着写的例子，上面绿色加粗部分，我还是没明白，希望大神解释。
