一個可以讓你有更多時間摸魚的WPF控制項（二）

前言上文介紹瞭如何通過一個Form自定義控制項來簡化數據的錄入，並自動實現數據校驗，自動佈局排列等功能。本文繼續介紹如何優化表格控制項的使用，縮減代碼量，實現工作效率的提升。一、功能實現上文中分析了DataGrid跟ListView兩種表格控制項的優劣，在這裡我們選擇ListView來實現我們的表格 ...

前言

上文介紹瞭如何通過一個Form自定義控制項來簡化數據的錄入，並自動實現數據校驗，自動佈局排列等功能。本文繼續介紹如何優化表格控制項的使用，縮減代碼量，實現工作效率的提升。

一、功能實現

上文中分析了DataGrid跟ListView兩種表格控制項的優劣，在這裡我們選擇ListView來實現我們的表格功能，如有疑問請看上一篇文章，這裡不再贅述。

下麵我們定義一個ListViewExtensions靜態類來實現ListView的附加屬性，併在附加屬性更改後實現ListView的優化功能。

public static class ListViewExtensions
    {
        #region AutoGenerateColumns
        public static readonly DependencyProperty AutoGenerateColumnsProperty =
            DependencyProperty.RegisterAttached("AutoGenerateColumns", typeof(bool), typeof(ListViewExtensions), new PropertyMetadata(false, AutoGenerateColumnsChanged));

        public static bool GetAutoGenerateColumns(DependencyObject obj)
        {
            return (bool)obj.GetValue(AutoGenerateColumnsProperty);
        }

        public static void SetAutoGenerateColumns(DependencyObject obj, bool value)
        {
            obj.SetValue(AutoGenerateColumnsProperty, value);
        }

        private static void AutoGenerateColumnsChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
        {
            ListView listView = obj as ListView;
            bool autoGenerateColumns = (bool)e.NewValue;

            if (listView != null)
            {
                if (autoGenerateColumns)
                {
                    listView.Loaded += ListViewLoadedHandler;

                }
                else
                {
                    listView.Loaded -= ListViewLoadedHandler;
                }
            }
        }

        private static void ListViewLoadedHandler(object sender, RoutedEventArgs e)
        {
            var listView = (ListView)sender;
            if (listView.ItemsSource == null) return;

            var itemType = listView.ItemsSource.GetType().GetGenericArguments().FirstOrDefault();
            if (itemType != null)
            {
                // 獲取數據源的屬性信息
                var properties = itemType.GetProperties();
                GridView gridView = null;
                if (listView.View is GridView gv)
                {
                    gridView = gv;
                }
                else
                {
                    listView.View = gridView = new GridView();
                }

                // 根據屬性信息創建列並添加到 GridView 中
                var optionMappingConverter = new OptionMappingConverter();
                var enumDescriptionConverter = new EnumDescriptionConverter();
                foreach (PropertyInfo property in properties)
                {
                    //排除無用屬性
                    var name = property.Name;
                    if (PropertyHelper.IgnoredProperties.Contains(property.Name)) continue;

                    //讀取列參數
                    var columnAttribute = property.GetCustomAttributes().OfType<ColumnAttribute>().FirstOrDefault();
                    if (columnAttribute == null || !columnAttribute.IsVisible) continue;

                    //排除重覆屬性
                    var targetColumn = gridView.Columns.FirstOrDefault(item => GetColumnName(item) == property.Name);
                    if (targetColumn != null)
                    {
                        if (targetColumn.Header == null)
                            targetColumn.Header = columnAttribute.Name;
                        SetColumnIndex(targetColumn, columnAttribute.Order);
                        continue;
                    }

                    var column = new GridViewColumn() { Header = !string.IsNullOrEmpty(columnAttribute.Name) ? columnAttribute.Name : name };
                    SetColumnName(column, property.Name);
                    //分組
                    if (columnAttribute is GroupColumnAttribute group) ListViewExtensions.SetGroup(column, group.Group);
                    //寬度
                    if (columnAttribute.Width > 0) column.Width = columnAttribute.Width;
                    //轉換器
                    if (columnAttribute.Converter != null)
                    {
                        column.DisplayMemberBinding = new Binding(property.Name)
                        {
                            Converter = Activator.CreateInstance(columnAttribute.Converter) as IValueConverter,
                            ConverterParameter = columnAttribute.ConverterParameter,
                            StringFormat = columnAttribute.StringFormat
                        };
                    }
                    else
                    {
                        //指定轉換器
                        var optionMappingAttribute = property.GetCustomAttributes().OfType<OptionMappingAttribute>().FirstOrDefault();
                        if (optionMappingAttribute != null)
                        {
                            column.DisplayMemberBinding = new Binding(property.Name)
                            {
                                Converter = optionMappingConverter,
                                ConverterParameter = optionMappingAttribute.Mapping
                            };
                        }
                        else if (property.PropertyType.IsEnum)
                        {
                            column.DisplayMemberBinding = new Binding(property.Name)
                            {
                                Converter = enumDescriptionConverter,
                                StringFormat = columnAttribute.StringFormat
                            };
                        }
                        else
                        {
                            column.DisplayMemberBinding = new Binding(property.Name) { StringFormat = columnAttribute.StringFormat };
                        }
                    }

                    SetColumnIndex(column, columnAttribute.Order);
                    gridView.Columns.Add(column);
                }

                var cols = gridView.Columns.OrderBy(item => GetColumnIndex(item)).ToArray();
                gridView.Columns.Clear();
                foreach (var col in cols)
                {
                    gridView.Columns.Add(col);
                }
            }
        }
        #endregion

        #region ColumnIndex
        public static int GetColumnIndex(DependencyObject obj)
        {
            return (int)obj.GetValue(ColumnIndexProperty);
        }

        public static void SetColumnIndex(DependencyObject obj, int value)
        {
            obj.SetValue(ColumnIndexProperty, value);
        }

        public static readonly DependencyProperty ColumnIndexProperty =
            DependencyProperty.RegisterAttached("ColumnIndex", typeof(int), typeof(ListViewExtensions), new PropertyMetadata(0));

        #endregion

        #region ColumnName
        public static string GetColumnName(DependencyObject obj)
        {
            return (string)obj.GetValue(ColumnNameProperty);
        }

        public static void SetColumnName(DependencyObject obj, string value)
        {
            obj.SetValue(ColumnNameProperty, value);
        }


        public static readonly DependencyProperty ColumnNameProperty =
            DependencyProperty.RegisterAttached("ColumnName", typeof(string), typeof(ListViewExtensions));
        #endregion

        #region Group
        public static string GetGroup(DependencyObject obj)
        {
            return (string)obj.GetValue(GroupProperty);
        }

        public static void SetGroup(DependencyObject obj, string value)
        {
            obj.SetValue(GroupProperty, value);
        }

        public static readonly DependencyProperty GroupProperty =
            DependencyProperty.RegisterAttached("Group", typeof(string), typeof(ListViewExtensions));

        #endregion
    }

二、示例代碼

View

<ListView extensions:ListViewExtensions.AutoGenerateColumns="True" ItemsSource="{Binding Collection}"/>

Model

 public class Person : ValidationObjectBase
    {
        private string _name;
        private DateTime _dateOfBirth = DateTime.Now;
        private int _age;
        private int _gender = 1;
        private string _phoneNumber;
        private string _email;
        private string _address;
        private string _idCardNumber;
        private EducationInfo _education;
        private MaritalStatus _maritalStatus;

        /// <summary>
        /// 姓名
        /// </summary>
        [Column(Name = "姓名", Order = 1)]
        public string Name
        {
            get => _name;
            set => this.SetProperty(ref _name, value);
        }

        /// <summary>
        /// 出生日期
        /// </summary>
        [Column(Name = "出生日期", StringFormat = "{0:yyyy年MM月dd日}", Order = 2)]
        public DateTime DateOfBirth
        {
            get => _dateOfBirth;
            set => this.SetProperty(ref _dateOfBirth, value);
        }

        /// <summary>
        /// 年齡
        /// </summary>
        [Column(Name = "年齡", Order = 3)]
        public int Age
        {
            get => _age;
            set => this.SetProperty(ref _age, value);
        }

        /// <summary>
        /// // 性別
        /// </summary>
        [Column(Name = "性別", Order = 4)]
        public int Gender
        {
            get => _gender;
            set => this.SetProperty(ref _gender, value);
        }

        /// <summary>
        /// 手機號碼
        /// </summary>
        [Column(Name = "電話號碼", Order = 5)]
        public string PhoneNumber
        {
            get => _phoneNumber;
            set => this.SetProperty(ref _phoneNumber, value);
        }

        /// <summary>
        /// 電子郵箱
        /// </summary>
        [Column(Name = "電子郵箱", Order = 6)]
        public string Email
        {
            get => _email;
            set => this.SetProperty(ref _email, value);
        }

        /// <summary>
        /// 地址信息
        /// </summary>
        [Column(Name = "地址", Order = 7)]
        public string Address
        {
            get => _address;
            set => this.SetProperty(ref _address, value);
        }

        /// <summary>
        /// 身份證號碼
        /// </summary>
        [Column(Name = "身份證號碼", Order = 8)]
        public string IdCardNumber
        {
            get => _idCardNumber;
            set => this.SetProperty(ref _idCardNumber, value);
        }

        /// <summary>
        /// 教育信息
        /// </summary>
        //[Column(Name = "教育信息", IsVisible = false, Order = 9)]
        public EducationInfo Education
        {
            get => _education;
            set => this.SetProperty(ref _education, value);
        }

        /// <summary>
        /// 婚姻狀況
        /// </summary>
        [Column(Name = "婚姻狀況", Order = 10)]
        public MaritalStatus MaritalStatus
        {
            get => _maritalStatus;
            set => this.SetProperty(ref _maritalStatus, value);
        }
}

ViewModel

public class FormDemoViewModel : BindableBase
    {
        public ObservableCollection<Person> Collection
        {
            get { return _collection; }
            set { this.SetProperty(ref _collection, value); }
        }
    }

三、答疑解惑

2.1 如何添加自定義列？

答：可以按常規方式添加自定義列，用ListViewExtensions.ColumnIndex來指定位的位置，以下為示例代碼。

<ListView extensions:ListViewExtensions.AutoGenerateColumns="True" ItemsSource="{Binding Collection}">
    <GridView>
        <GridViewColumn extensions:ListViewExtensions.ColumnIndex="0">
            <GridViewColumn.Header>
                <CheckBox Content="全選" />
            </GridViewColumn.Header>
            <GridViewColumn.CellTemplate>
                <DataTemplate>
                    <CheckBox />
                </DataTemplate>
            </GridViewColumn.CellTemplate>
        </GridViewColumn>
    </GridView>
</ListView>

2.2 如何自動生成的列不滿足需求，可不可以自己定義列？

答：可以，使用ListViewExtensions.ColumnName屬性可以覆蓋某一個列的自動生成的操作。

<ListView extensions:ListViewExtensions.AutoGenerateColumns="True" ItemsSource="{Binding Collection}">
    <GridView>
        <GridViewColumn
                    extensions:ListViewExtensions.ColumnIndex="1"
                    extensions:ListViewExtensions.ColumnName="Name">
            <GridViewColumn.CellTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding Name}" />
                </DataTemplate>
            </GridViewColumn.CellTemplate>
        </GridViewColumn>
    </GridView>
</ListView>

2.3 如何給列設置順序？

答：在屬性上給ColumnAttribute特性設置參數Order。

[Column(Name = "出生日期", Order = 2)]
public DateTime DateOfBirth
{
      get => _dateOfBirth;
      set => this.SetProperty(ref _dateOfBirth, value);
}

2.4 如何設置列的寬度？

答：在屬性上給ColumnAttribute特性設置參數Width。

[Column(Name = "出生日期", Width =100)]
public DateTime DateOfBirth
{
      get => _dateOfBirth;
      set => this.SetProperty(ref _dateOfBirth, value);
}

2.5 如何將列設為不可見？

答：在屬性上給ColumnAttribute特性設置參數IsVisible。

[Column(Name = "出生日期", IsVisible = false)]
public DateTime DateOfBirth
 {
       get => _dateOfBirth;
       set => this.SetProperty(ref _dateOfBirth, value);
}

2.6 如何給綁定設置格式化字元串？

答：在屬性上給ColumnAttribute特性設置參數StringFormat。

[Column(Name = "出生日期", StringFormat = "{0:yyyy年MM月dd日}")]
public DateTime DateOfBirth
{
      get => _dateOfBirth;
      set => this.SetProperty(ref _dateOfBirth, value);
}

2.7 如何給綁定設置轉換器及參數？

答：在屬性上給ColumnAttribute特性設置Converter和ConverterParameter參數。

[Column(Name = "出生日期", Converter = typeof(TestConverter), ConverterParameter=1)]
public DateTime DateOfBirth
{
      get => _dateOfBirth;
      set => this.SetProperty(ref _dateOfBirth, value);
}

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