取物件的名稱與屬性名稱

從資料庫撈取出幾筆資料出來後對應的物件如下

public class SNMPTrapView
{
    public long Id { get; set; }
 
    [Display(Name = "ID")]
    public string TrapId { get; set; }
 
    [Display(Name = "時間")]
    public string TrappedOn { get; set; }
 
    [Display(Name = "類型")]
    public string Type { get; set; }
 
    public string Status { get; set; }
 
    [Display(Name = "內容")]
    public string Content { get; set; }
 
    [Display(Name = "說明")]
    public string Desc { get; set; }
 
    [Display(Name = "結案")]
    public string Done { get; set; }
}

案例: 想要匯出到excel，但是只想要顯示有DisplayAttribute的欄位

參考了這兩篇文章
https://stackoverflow.com/questions/7027613/how-to-retrieve-data-annotations-from-code-programmatically
https://stackoverflow.com/questions/6637679/reflection-get-attribute-name-and-value-on-property

改寫成

public static List<Tuple<string, string>> GetPropNameAndAttrName<T>()
{
    var result = new List<Tuple<string, string>>();
    PropertyInfo[] props = typeof(T).GetProperties();
    foreach (PropertyInfo prop in props)
    {
        object[] attrs = prop.GetCustomAttributes(true);
        if (attrs.Any())
        {
            var attr = (DisplayAttribute)attrs[0];
            if (!string.IsNullOrEmpty(attr.Name))
            {
                result.Add(new Tuple<string, string>(prop.Name, attr.Name));
            }
        }
    }
    return result;
}

透過 .Net Core API 網站顯示

[HttpGet("obj")]
public IActionResult GetObject()
{
    return new ObjectResult(CommonTool.GetPropNameAndAttrName<SNMPTrapView>());
}

瀏覽器顯示結果

確定如預期，完成剩下的程式，產出excel報表

// GET: api/snmptrap/excel
[HttpGet("excel")]
public async Task<IActionResult> GenerateExcelAsync(SNMPTrapSearching model)
{
    var report = await Task.Factory.StartNew(() => _snmpTrapService.Get(model));
 
    var memoryStream = new MemoryStream();
    using (var document = SpreadsheetDocument.Create(memoryStream, SpreadsheetDocumentType.Workbook))
    {
        var sheetData = CommonTool.CreateSheetData(document, "SNMPTrap");
        var props = CommonTool.GetPropNameAndAttrName<SNMPTrapView>();
        var row = new Row();
        foreach (var prop in props) // header
        {
            row.Append(new Cell()
            {
                CellValue = new CellValue(prop.Item2),
                DataType = CellValues.String
            });
        }
        sheetData.AppendChild(row);
 
        foreach (var item in report) // body
        {
            row = new Row();
            foreach (var prop in props)
            {
                var value = (string)item.GetType().GetProperty(prop.Item1).GetValue(item, null);
                row.Append(new Cell()
                {
                    CellValue = new CellValue(value),
                    DataType = CellValues.String
                });
            }
            sheetData.AppendChild(row);
        }
    }
 
    memoryStream.Seek(0, SeekOrigin.Begin);
    var fileName = $"SNMPTrap_Report_{DateTime.Now.ToString("yyyyMMddHHmmssfff")}.xlsx";
    return File(memoryStream, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", fileName);
}