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示例:WPF中应用DataGrid读取实体DisplayAttribute特性自动自动生成列名

news 来源：原创 2024/9/29 11:22:56

一、目的：通过重写DataGrid的OnAutoGeneratingColumn方法实现根据定义特性自动生成列头信息功能

二、实现

<DataGrid ItemsSource="{local:GetStudents Count=50}"/>

实体定义如下

 public class Student{[DataGridColumn("*")][Display(Name = "姓名", GroupName = "基础信息")][Required]public string Name { get; set; }[DataGridColumn("*")][Display(Name = "班级", GroupName = "基础信息")][Required]public string Class { get; set; }[DataGridColumn("2*")][Display(Name = "地址", GroupName = "基础信息")][Required]public string Address { get; set; }[DataGridColumn("2*")][Display(Name = "邮箱", GroupName = "基础信息")][Required]public string Emall { get; set; }[Display(Name = "可用", GroupName = "其他信息")][Required]public bool IsEnbled { get; set; }[Display(Name = "时间", GroupName = "其他信息")][Required]public DateTime Time { get; set; }[Display(Name = "年龄", GroupName = "基础信息")][Required]public int Age { get; set; }[Display(Name = "分数", GroupName = "成绩信息")]public double Score { get; set; }[DataGridColumn("2*")][Display(Name = "电话号码", GroupName = "基础信息")][Required][RegularExpression("^1[3|4|5|7|8][0-9]{9}$", ErrorMessage = "手机号码不合法！")]public string Tel { get; set; }}

通常如上定义会生成一个根据属性名称列头的表格

三、环境

VS2022

四、示例

自定义一个DislayDataGrid,重写OnAutoGeneratingColumn方法

    public class DislayDataGrid : DataGrid{protected override void OnAutoGeneratingColumn(DataGridAutoGeneratingColumnEventArgs e){base.OnAutoGeneratingColumn(e);if (e.PropertyDescriptor is PropertyDescriptor descriptor)e.Column.Header = descriptor.Attributes.OfType<DisplayAttribute>()?.FirstOrDefault().Name;}}

此时会根据读取特性生成中文名称列头

同理其他属性也可以这样设置

我们扩展一个特性DataGridColumnAttribute

    [AttributeUsage(AttributeTargets.Property, Inherited = false, AllowMultiple = false)]public class DataGridColumnAttribute : Attribute, IDataGridColumn{public DataGridColumnAttribute(string width){DataGridLengthConverter converter = new DataGridLengthConverter();this.Width = (DataGridLength)converter.ConvertFromString(width);}public DataGridColumnAttribute(){}public DataGridLength Width { get; set; } = DataGridLength.Auto;public Type Template { get; set; } = typeof(DataGridTextColumn);/// <summary>/// "{0}.Property"/// </summary>public string PropertyPath { get; set; } = "{0}";public virtual DataGridColumn GetDataGridColumn(PropertyInfo propertyInfo){DataGridColumn dataGridColumn = Activator.CreateInstance(this.Template) as DataGridColumn;if (dataGridColumn == null){if (propertyInfo.PropertyType == typeof(bool)){return new DataGridCheckBoxColumn() { Width = this.Width, IsReadOnly = false };}else if (propertyInfo.PropertyType.IsEnum){return new DataGridComboBoxColumn() { Width = this.Width, IsReadOnly = false };}else{return new DataGridTextColumn() { Width = this.Width, IsReadOnly = false };}}dataGridColumn.Width = this.Width;return dataGridColumn;}}

在生成列时应用该特性

此时列宽也根据特性变化

如果不想通过自定义DisplayDataGrid实现也可以用Behavior行为的方式实现

实现方式如下：

    <DataGrid ItemsSource="{h:GetStudents Count=50}"><b:Interaction.Behaviors><h:DataGridAutoColumnBehavior Type="{x:Type h:Student}"/></b:Interaction.Behaviors></DataGrid>

DataGridAutoColumnBehavior的具体实现方式如下

WPF-Control/Source/Extensions/H.Extensions.Behvaiors/DataGrid/DataGridAutoColumnBehavior.cs at main · HeBianGu/WPF-Control · GitHub

这种方式在自动化生成表格数据中非常有用