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

news2024/10/5 19:55:55

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