.NET 使用动态列设置获取数据表行

Question

我有 2 个数据表，dt_columns 和 dt_rows； dt_columns 有一个动态列 dt_rows。如何使用dt_columns 中的IEnumerable<string> 检索/选择来自dt_rows 的数据、字段并将其导出到文本文件中？

dt_columns数据表：

header_name	custom_header_name
column1	custom_header_1
column2	custom_header_2

dt_rows数据表：

id	column1	column2
1	Value1.1	Value1.2
2	Value2.1	Value2.2

文本文件中的预期输出：

custom_header_1	custom_header_2
Value1.1	Value1.2
Value2.1	Value2.2

这是我前进方向的骨架：

StringBuilder sb = new StringBuilder();

DataTable dt_headers = new DataTable();
DataTable dt_rows = new DataTable();

using (var reader = ObjectReader.Create(data)) {
    dt_rows.Load(reader);
}

using (var reader = ObjectReader.Create(headers)) {
    dt_headers.Load(reader);
}

IEnumerable<string> column_names = dt_headers.Rows.Cast<DataRow>()
                                                .Select(row => (
                                                    row["custom_header_name"].ToString() == "" ? row["header_name"].ToString() : row["custom_header_name"].ToString()
                                                ));
sb.AppendLine(string.Join(delimeter, column_names));

foreach(DataRow row in dt_rows.Rows) {
     IEnumerable<string> fields = row.ItemArray.Select(field =>
     String.Concat("\"", field.ToString().Replace("\"", "\"\""), "\"")); 

     sb.AppendLine(string.Join(delimeter, fields));
}

using (StreamWriter output = new StreamWriter(Path.Combine(AppDomain.CurrentDomain.BaseDirectory + "\\" + "resources\\", file_name + ".txt")))
{
   output.WriteLine(sb.ToString());
   output.Close();
}

Answer 1

我认为这样的事情应该可行：

string[] colNames = dt_headers.AsEnumerable().Select(r => r.Field<string>("header_name")).ToArray();
string[] custColNames = dt_headers.AsEnumerable().Select(r => r.Field<string>("custom_header_name")).ToArray();

// build row values separated by the delimiter as strings
IEnumerable<string> data = dt_rows.AsEnumerable()
    .Select(r => string.Join(delimiter, colNames.Select(c => r.Field<string>(c))));
// prepend header(custom column names):
data = data.Prepend(string.Join(delimiter, custColNames));

// write to text-file
File.WriteAllLines(
    Path.Combine(AppDomain.CurrentDomain.BaseDirectory + "\\" + "resources\\", file_name + ".txt"),
    data);