Preparation for Prism

　　Prism框架由MS patterns&practices团队开发。下面是Prism的介绍：

　　Prism provides guidance designed to help you more easily design and build rich, flexible, and easy-to-maintain Windows Presentation Foundation (WPF) desktop applications and Silverlight Rich Internet Applications (RIAs) and Windows Phone 7 applications. Using design patterns that embody important architectural design principles, such as separation of concerns and loose coupling, Prism helps you to design and build applications using loosely coupled components that can evolve independently but which can be easily and seamlessly integrated into the overall application. These types of applications are known as composite applications.

　　其下载地址：Prism ，可以从这里下载最新的Prism及相关的文档，目前最新版本为4.1。

选择最新的prism4.1（文件不大23.69M）下载后，释放到指定的位置，其中包含的内容如下：

可见，其中大概包含三类文件。

1.类似于Desktop only-Prism Library.bat的批处理文件，用来打开相应的Prism项目。因为我们打开这个bat文件，其内容如下：

@call "PrismLibrary\PrismLibrary_desktop.sln"

我们打开这个项目，可以发现DebugLZQ前一篇博文中的类似的类，DelegateCommand以及NotificationObject如下：

这两个类DelegeteCommand和NotificationObject在Prism中的实现如下：

View Code

//===================================================================================
// Microsoft patterns & practices
// Composite Application Guidance for Windows Presentation Foundation and Silverlight
//===================================================================================
// Copyright (c) Microsoft Corporation.  All rights reserved.
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY
// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT
// LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
// FITNESS FOR A PARTICULAR PURPOSE.
//===================================================================================
// The example companies, organizations, products, domain names,
// e-mail addresses, logos, people, places, and events depicted
// herein are fictitious.  No association with any real company,
// organization, product, domain name, email address, logo, person,
// places, or events is intended or should be inferred.
//===================================================================================
using System;
using System.Windows.Input;
using Microsoft.Practices.Prism.Properties;

namespace Microsoft.Practices.Prism.Commands
{
    /// <summary>
    /// An <see cref="ICommand"/> whose delegates can be attached for <see cref="Execute"/> and <see cref="CanExecute"/>.
    /// It also implements the <see cref="IActiveAware"/> interface, which is useful when registering this command in a <see cref="CompositeCommand"/> that monitors command's activity.
    /// </summary>
    /// <typeparam name="T">Parameter type.</typeparam>
    /// <remarks>
    /// The constructor deliberately prevent the use of value types.
    /// Because ICommand takes an object, having a value type for T would cause unexpected behavior when CanExecute(null) is called during XAML initialization for command bindings.
    /// Using default(T) was considered and rejected as a solution because the implementor would not be able to distinguish between a valid and defaulted values.
    /// <para/>
    /// Instead, callers should support a value type by using a nullable value type and checking the HasValue property before using the Value property.
    /// <example>
    ///     <code>
    /// public MyClass()
    /// {
    ///     this.submitCommand = new DelegateCommand&lt;int?&gt;(this.Submit, this.CanSubmit);
    /// }
    /// 
    /// private bool CanSubmit(int? customerId)
    /// {
    ///     return (customerId.HasValue &amp;&amp; customers.Contains(customerId.Value));
    /// }
    ///     </code>
    /// </example>
    /// </remarks>
    public class DelegateCommand<T> : DelegateCommandBase        
    {        
        /// <summary>
        /// Initializes a new instance of <see cref="DelegateCommand{T}"/>.
        /// </summary>
        /// <param name="executeMethod">Delegate to execute when Execute is called on the command.  This can be null to just hook up a CanExecute delegate.</param>
        /// <remarks><seealso cref="CanExecute"/> will always return true.</remarks>
        public DelegateCommand(Action<T> executeMethod)
            : this(executeMethod, (o)=>true)
        {            
        }

        /// <summary>
        /// Initializes a new instance of <see cref="DelegateCommand{T}"/>.
        /// </summary>
        /// <param name="executeMethod">Delegate to execute when Execute is called on the command.  This can be null to just hook up a CanExecute delegate.</param>
        /// <param name="canExecuteMethod">Delegate to execute when CanExecute is called on the command.  This can be null.</param>
        /// <exception cref="ArgumentNullException">When both <paramref name="executeMethod"/> and <paramref name="canExecuteMethod"/> ar <see langword="null" />.</exception>
        public DelegateCommand(Action<T> executeMethod, Func<T, bool> canExecuteMethod)
            : base((o) => executeMethod((T)o), (o) => canExecuteMethod((T)o))
        {
            if (executeMethod == null || canExecuteMethod == null)
                throw new ArgumentNullException("executeMethod", Resources.DelegateCommandDelegatesCannotBeNull);

#if !WINDOWS_PHONE
            Type genericType = typeof(T);

            // DelegateCommand allows object or Nullable<>.  
            // note: Nullable<> is a struct so we cannot use a class constraint.
            if (genericType.IsValueType)
            {
                if ((!genericType.IsGenericType) || (!typeof(Nullable<>).IsAssignableFrom(genericType.GetGenericTypeDefinition())))
                {
                    throw new InvalidCastException(Resources.DelegateCommandInvalidGenericPayloadType);
                }
            }
#endif
        }

        ///<summary>
        ///Determines if the command can execute by invoked the <see cref="Func{T,Bool}"/> provided during construction.
        ///</summary>
        ///<param name="parameter">Data used by the command to determine if it can execute.</param>
        ///<returns>
        ///<see langword="true" /> if this command can be executed; otherwise, <see langword="false" />.
        ///</returns>
        public bool CanExecute(T parameter)
        {
            return base.CanExecute(parameter);
        }

        ///<summary>
        ///Executes the command and invokes the <see cref="Action{T}"/> provided during construction.
        ///</summary>
        ///<param name="parameter">Data used by the command.</param>
        public void Execute(T parameter)
        {
            base.Execute(parameter);
        }
    }

    /// <summary>
    /// An <see cref="ICommand"/> whose delegates do not take any parameters for <see cref="Execute"/> and <see cref="CanExecute"/>.
    /// </summary>
    /// <seealso cref="DelegateCommandBase"/>
    /// <seealso cref="DelegateCommand{T}"/>
    public class DelegateCommand : DelegateCommandBase
    {
        /// <summary>
        /// Creates a new instance of <see cref="DelegateCommand"/> with the <see cref="Action"/> to invoke on execution.
        /// </summary>
        /// <param name="executeMethod">The <see cref="Action"/> to invoke when <see cref="ICommand.Execute"/> is called.</param>
        public DelegateCommand(Action executeMethod) : this(executeMethod, ()=>true)
        {
        }

        /// <summary>
        /// Creates a new instance of <see cref="DelegateCommand"/> with the <see cref="Action"/> to invoke on execution
        /// and a <see langword="Func" /> to query for determining if the command can execute.
        /// </summary>
        /// <param name="executeMethod">The <see cref="Action"/> to invoke when <see cref="ICommand.Execute"/> is called.</param>
        /// <param name="canExecuteMethod">The <see cref="Func{TResult}"/> to invoke when <see cref="ICommand.CanExecute"/> is called</param>
        public DelegateCommand(Action executeMethod, Func<bool> canExecuteMethod)
            :base((o) => executeMethod(), (o)=>canExecuteMethod())
        {
            if (executeMethod == null || canExecuteMethod == null)
                throw new ArgumentNullException("executeMethod", Resources.DelegateCommandDelegatesCannotBeNull);
        }


        ///<summary>
        /// Executes the command.
        ///</summary>
        public void Execute()
        {
            Execute(null);
        }

        /// <summary>
        /// Determines if the command can be executed.
        /// </summary>
        /// <returns>Returns <see langword="true"/> if the command can execute,otherwise returns <see langword="false"/>.</returns>
        public bool CanExecute()
        {
            return CanExecute(null);
        }
    }
    
}

View Code

//===================================================================================
// Microsoft patterns & practices
// Composite Application Guidance for Windows Presentation Foundation and Silverlight
//===================================================================================
// Copyright (c) Microsoft Corporation.  All rights reserved.
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY
// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT
// LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
// FITNESS FOR A PARTICULAR PURPOSE.
//===================================================================================
// The example companies, organizations, products, domain names,
// e-mail addresses, logos, people, places, and events depicted
// herein are fictitious.  No association with any real company,
// organization, product, domain name, email address, logo, person,
// places, or events is intended or should be inferred.
//===================================================================================
using System;
using System.ComponentModel;
using System.Diagnostics.CodeAnalysis;
using System.Linq.Expressions;

namespace Microsoft.Practices.Prism.ViewModel
{
    /// <summary>
    /// Base class for items that support property notification.
    /// </summary>
    /// <remarks>
    /// This class provides basic support for implementing the <see cref="INotifyPropertyChanged"/> interface and for
    /// marshalling execution to the UI thread.
    /// </remarks>
#if SILVERLIGHT
        [System.Runtime.Serialization.DataContract]
#else
        [Serializable]
#endif
    public abstract class NotificationObject : INotifyPropertyChanged
    {
        /// <summary>
        /// Raised when a property on this object has a new value.
        /// </summary>        
#if !SILVERLIGHT
        [field: NonSerialized]
#endif
        public event PropertyChangedEventHandler PropertyChanged;

        /// <summary>
        /// Raises this object's PropertyChanged event.
        /// </summary>
        /// <param name="propertyName">The property that has a new value.</param>
        [SuppressMessage("Microsoft.Design", "CA1030:UseEventsWhereAppropriate", Justification = "Method used to raise an event")]
        protected virtual void RaisePropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler handler = this.PropertyChanged;
            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(propertyName));
            }
        }

        /// <summary>
        /// Raises this object's PropertyChanged event for each of the properties.
        /// </summary>
        /// <param name="propertyNames">The properties that have a new value.</param>
        [SuppressMessage("Microsoft.Design", "CA1030:UseEventsWhereAppropriate", Justification = "Method used to raise an event")]
        protected void RaisePropertyChanged(params string[] propertyNames)
        {
            if (propertyNames == null) throw new ArgumentNullException("propertyNames");

            foreach (var name in propertyNames)
            {
                this.RaisePropertyChanged(name);
            }
        }

        /// <summary>
        /// Raises this object's PropertyChanged event.
        /// </summary>
        /// <typeparam name="T">The type of the property that has a new value</typeparam>
        /// <param name="propertyExpression">A Lambda expression representing the property that has a new value.</param>
        [SuppressMessage("Microsoft.Design", "CA1030:UseEventsWhereAppropriate", Justification = "Method used to raise an event")]
        [SuppressMessage("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures", Justification = "Cannot change the signature")]
        protected void RaisePropertyChanged<T>(Expression<Func<T>> propertyExpression)
        {
            var propertyName = PropertySupport.ExtractPropertyName(propertyExpression);
            this.RaisePropertyChanged(propertyName);
        }
    }
}