DW5S/DW5S.App/Basic/BindingData.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.ComponentModel;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;

/// <summary>
/// <para>一个更高性能的用于数据绑定的对象,继承自BindingList对象</para>
/// <para>添加了AddRange、InsertRange,支持批量添加后再整体刷新视图,提高性能</para>
/// <para>添加了几个常用的类似Linq中List的函数</para>
/// <para>该对象可直接用于json序列化和反序列化,其结果和List一样</para>
/// </summary>
/// <typeparam name="T">泛型对象</typeparam>
/// <remarks>BindingData不具有线程安全特性,该对象应该只初始化一次,通过Clear、Add等更新</remarks>
public class BindingData<T> : BindingList<T> where T : class, new()
{
    public event Action<T> OnItemDelete;
    public BindingData()
        : base()
    {
    }
    /// <summary>
    /// 是否支持排序
    /// </summary>
    protected override bool SupportsSortingCore
    {
        get { return true; }
    }
    /// <summary>
    /// 是否支持搜索
    /// </summary>
    protected override bool SupportsSearchingCore
    {
        get { return true; }
    }
    protected override void RemoveItem(int itemIndex)
    {
        OnItemDelete?.Invoke(this[itemIndex]);
        base.RemoveItem(itemIndex);
    }

    public BindingData(IEnumerable<T> data)
    {
        //构造函数中不会触发OnListChanged
        this.AddRange(data);
    }
    public void AddRange(IEnumerable<T> items)
    {
        if (items == null || items.Count() == 0) return;
        RaiseListChangedEvents = false;//让View不刷新
        foreach (var item in items)
        {
            Add(item);
        }
        OnListChanged(new ListChangedEventArgs(ListChangedType.Reset, 0));//批量更新View
        RaiseListChangedEvents = true;//让View继续更新
    }
    public void InsertRange(IEnumerable<T> items)
    {
        if (items == null || items.Count() == 0) return;
        RaiseListChangedEvents = false;//让View不刷新
        int count = items.Count();
        for (int i = count - 1; i >= 0; i--)
        {
            InsertItem(0, items.ElementAt(i));
        }
        OnListChanged(new ListChangedEventArgs(ListChangedType.Reset, 0));//批量更新View
        RaiseListChangedEvents = true;//让View继续更新
    }
    public T[] GetRows(int[] rows)
    {
        if (this.Count < 0) return null;
        List<T> list = new List<T>();
        foreach (var index in rows)
        {
            if (index < 0 || index >= this.Count) continue;
            list.Add(this[index]);
        }
        return list.ToArray();
    }
    public int RemoveAll(Predicate<T> match)
    {
        var list = this.FindAll(match);
        RaiseListChangedEvents = false;//让View不刷新
        int i = 0;
        foreach (var item in list)
        {
            if (this.Remove(item)) i++;
        }
        OnListChanged(new ListChangedEventArgs(ListChangedType.Reset, 0));//批量更新View
        RaiseListChangedEvents = true;//让View继续更新
        return i;
    }
    public void RemoveAll(T[] data)
    {
        foreach (var item in data)
        {
            this.Remove(item);
        }
    }
    public T Find(Predicate<T> match)
    {
        foreach (var item in this)
        {
            if (match(item))
                return item;
        }
        return default;
    }

    public List<T> FindAll(Predicate<T> match)
    {
        List<T> list = new List<T>();
        foreach (var item in this)
        {
            if (match(item))
                list.Add(item);
        }
        return list;
    }
    public int FindIndex(Predicate<T> match)
    {
        int idx = 0;
        foreach (var item in this)
        {
            if (match(item))
                return idx;
            idx++;
        }
        return -1;
    }
    public bool Exists(Predicate<T> match)
    {
        foreach (var item in this)
        {
            if (match(item))
                return true;
        }
        return false;
    }
    public void SortData(Expression<Func<T, dynamic>> express, bool asc = true)
    {
        RaiseListChangedEvents = false;//让View不刷新
        List<T> tmp;
        if (asc)
            tmp = this.OrderBy(express.Compile()).ToList();
        else
            tmp = this.OrderByDescending(express.Compile()).ToList();
        this.Clear();
        this.AddRange(tmp);
        RaiseListChangedEvents = true;//让View继续更新
    }

    public List<T> DeepClone()
    {
        ParameterExpression parameterExpression = Expression.Parameter(typeof(T), "p");
        List<MemberBinding> memberBindingList = new List<MemberBinding>();

        foreach (var item in typeof(T).GetProperties())
        {
            if (!item.CanWrite)
                continue;

            MemberExpression property = Expression.Property(parameterExpression, typeof(T).GetProperty(item.Name));
            MemberBinding memberBinding = Expression.Bind(item, property);
            memberBindingList.Add(memberBinding);
        }

        MemberInitExpression memberInitExpression = Expression.MemberInit(Expression.New(typeof(T)), memberBindingList.ToArray());
        Expression<Func<T, T>> lambda = Expression.Lambda<Func<T, T>>(memberInitExpression, new ParameterExpression[] { parameterExpression });


        List<T> list = new List<T>();
        foreach (var item in this)
        {
            list.Add(lambda.Compile()(item));
        }
        return list;
    }
}