读取自定义属性的值

Question

我只想导出 Export = true 的属性。

我有另一种方法可以接受任何对象(不仅仅是PlanSetup(，解开包装，并将行添加到ExcelWorkBook。我已经设法获得了对象的类型，但是获取自定义属性的值是我挣扎的地方。我可以将行/列添加到 excel，但想在添加之前检查导出 = true。

按原样保留注释代码，以便您可以看到我尝试过的内容。

public class PlanSetup
{
public int PlanSetupLogID { get; set; }
[Custom(Export = true)]
public string PlanNumber { get; set; }
[Custom(Export = true)]
public string OrganizationID { get; set; }
[Custom(Export = true)]
public string AssociateID { get; set; }
public string ChangedFieldsList { get; set; }
public string GET_ResponseJSON { get; set; }
public string JSONRequest { get; set; }
public string JSONResponse { get; set; }
[Custom(Export = true)]
public string Status { get; set; }
[Custom(Export = true)]
public string CreatedDate { get; set; }
}
public async Task<byte[]> ExportDataToExcel(IEnumerable<object> data, string reportName = null)
{
byte[] excelData = null;
try
{
if (data != null)
{
Type type_info = data.FirstOrDefault().GetType();
System.Reflection.PropertyInfo[] properties_info = type_info.GetProperties();
//System.Reflection.MemberInfo info = 
System.Reflection.MemberInfo[] myMembers = type_info.GetMembers();
List<string> ExportColumns = new List<string>();
properties_info = properties_info.Where(item => item.CustomAttributes.Count() > 0).ToArray();
foreach (System.Reflection.PropertyInfo p in properties_info)
{
//if (p.CustomAttributes.Where(item => item.NamedArguments.Where(lol => lol.MemberInfo.Name);
//var ps = p.CustomAttributes.Where(item => item.NamedArguments.Where(sp => sp.MemberName == "Export");
//List<System.Reflection.CustomAttributeNamedArgument> cad = (System.Reflection.CustomAttributeNamedArgument)p.CustomAttributes.Select(item => item.NamedArguments).ToList();
}

//System.Reflection.MemberInfo info = typeof(type_info);

foreach (System.Reflection.MemberInfo m in myMembers)
{
if (m.CustomAttributes.Count() > 0)
{
if (m.Name == "Export")
{
ExportColumns.Add(m.Name);
}
}
foreach (object attrib in m.GetCustomAttributes(true))
{
Console.WriteLine(attrib);
}
}
//Object[] lolll = myMembers.Where(item => item.GetCustomAttributes(true));
//for (int i = 0; i < myMembers.Length; i++)
//{
//    Object[] myAttributes = myMembers[i].GetCustomAttributes(true);
//    if (myAttributes.Length > 0)
//    {
//        Console.WriteLine("nThe attributes for the member {0} are: n", myMembers[i]);
//        for (int j = 0; j < myAttributes.Length; j++)
//            Console.WriteLine("The type of the attribute is {0}.", myAttributes[j]);
//    }
//}
using (var package = new ExcelPackage())
{
//int x = 1, y = 1;
var worksheet = package.Workbook.Worksheets.Add(reportName);
int totalRows = data.Count();
int firstRow = 1;
int secondRow = 2;
int i = 1;
foreach (System.Reflection.PropertyInfo prop in properties_info)//Adding Headers
{
worksheet.Cells[firstRow, i].Value = prop.Name;
//if (prop.CustomAttributes.Select(item => item.NamedArguments[0].MemberName == "Export").FirstOrDefault())
//{
//    worksheet.Cells[firstRow, i].Value = prop.Name;
//}
//var lol = prop.CustomAttributes.Select(item => item.NamedArguments[0].MemberName == "Export");
//if(prop?.CustomAttributes?.Select(item=> item.NamedArguments.Select(i1=> i1.MemberName='Export')
i++;
}
foreach (var p in data)//Adding actual data rows.
{
int j = 1;
foreach (System.Reflection.PropertyInfo prop in properties_info)
{
worksheet.Cells[secondRow, j].Value = prop.GetValue(p, null);
j++;
//if (prop.CustomAttributes.Select(item => item.NamedArguments[0].MemberName == "Export").FirstOrDefault())
//{
//    worksheet.Cells[secondRow, j].Value = prop.GetValue(p, null);
//    j++;
//}
}
secondRow++;
}
string firstRowAllColumnsAddress = "A1:Y1";//worksheet.Cells[1, 1, 1, 24]
worksheet.Cells[firstRowAllColumnsAddress].Style.Font.Bold = true;
worksheet.Cells.AutoFitColumns();
await Task.Run(() => { excelData = package.GetAsByteArray(); });
}
}
}
catch (Exception e)
{
throw (e);
}
return excelData;
}


/***FIXED - Here is the working solution***/
public async Task<byte[]> ExportDataToExcel(IEnumerable<object> data, bool exportDecorator, string reportName = null)
{
byte[] excelData = null;
try
{
if (data != null)
{
Type type_info = data.FirstOrDefault().GetType();
System.Reflection.PropertyInfo[] properties_info = exportDecorator ? type_info.GetProperties().Where(p => p.GetCustomAttribute<CustomAttribute>()?.Export == true).ToArray() : type_info.GetProperties();
using (var package = new ExcelPackage())
{
//int x = 1, y = 1;
var worksheet = package.Workbook.Worksheets.Add(reportName);
int totalRows = data.Count();
int firstRow = 1;
int secondRow = 2;
int i = 1;
foreach (System.Reflection.PropertyInfo prop in properties_info)//Adding Headers
{
worksheet.Cells[firstRow, i].Value = prop.Name;
i++;
}
foreach (var p in data)//Adding actual data rows.
{
int j = 1;
foreach (System.Reflection.PropertyInfo prop in properties_info)
{
worksheet.Cells[secondRow, j].Value = prop.GetValue(p, null);
j++;
}
secondRow++;
}
string firstRowAllColumnsAddress = "A1:Y1";//worksheet.Cells[1, 1, 1, 24]
worksheet.Cells[firstRowAllColumnsAddress].Style.Font.Bold = true;
worksheet.Cells.AutoFitColumns();
await Task.Run(() => { excelData = package.GetAsByteArray(); });
}
}
}
catch (Exception e)
{
throw (e);
}
return excelData;
}

Answer 1

似乎您唯一的问题是检索[Custom(Export = true)]注释PropertyInfos那些。您可以通过以下方式实现：

var exportedProps = type_info.GetProperties()
.Where(p => p.PropertyType.GetCustomAttribute<CustomAttribute>()?.Export == true)