所以如果你的要求是：
使用 Linq
使用 StartsWith
代码
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
namespace ConsoleApp12
{
class Program
{
public static void Main(string[] args)
{
// test string
var str = @"BFFPPB10 Dark Chocolate Macadamia Nuts 11 oz (312g)\r\nINGREDIENTS: DARK CHOCOLATE (SUGAR, CHOCOLATE, COCOA BUTTER, \r\nANHYDROUS MILK FAT, SOY LECITHIN, VANILLA), MACADAMIA NUTS, SEA SALT.\r\nCONTAINS: MACADAMIA NUTS, MILK, SOY.\r\nALLERGEN INFORMATION: MAY CONTAIN OTHER TREE NUTS, PEANUTS, EGG AND\r\nWHEAT.\r\n01/11/2019\r\nDescription: Dry roasted, salted macadamias covered in dark chocolate.\r\nStorage Conditions: Store at ambient temperatures with a humidity less than 50%. \r\nShelf Life: 12 months\r\nBlain's Farm & Fleet\r\nItem No.: 701772\r\nBulk: 421172\r\nSupplier: Devon's\r\n";
// Keys
const string KEY_INGREDIENTS = "INGREDIENTS:";
const string KEY_CONTAINS = "CONTAINS:";
const string KEY_ALLERGEN_INFORMATION = "ALLERGEN INFORMATION:";
const string KEY_DESCRPTION = "Description:";
const string KEY_STORAGE_CONDITION = "Storage Conditions:";
const string KEY_SHELFLIFE = "Shelf Life:";
const string KEY_ITEM_NO = "Item No.:";
const string KEY_BULK = "Bulk:";
const string KEY_SUPPLIER = "Supplier:";
const string KEY_WARNING = "WARNING:";
const string KEY_YEAR_Regex = @"^\d{1,2}/\d{1,2}/\d{4}$";
const string KEY_AFTER_COMPANY_NAME = KEY_ITEM_NO;
// Helpers
var keys = new string[]
{ KEY_INGREDIENTS, KEY_CONTAINS, KEY_ALLERGEN_INFORMATION, KEY_DESCRPTION, KEY_STORAGE_CONDITION,
KEY_SHELFLIFE, KEY_ITEM_NO, KEY_BULK, KEY_SUPPLIER, KEY_WARNING };
var lines = str.Split(new string[] { @"\r\n" }, StringSplitOptions.RemoveEmptyEntries);
void log(string key, string val)
{
Console.WriteLine($"{key} => {val}");
Console.WriteLine();
}
void removeLine(string line)
{
if (line != null) lines = lines.Where(w => w != line).ToArray();
}
// get Multi Line Item with key
string getMultiLine(string key)
{
var line = lines
.Select((linetxt, index) => new { linetxt, index })
.Where(w => w.linetxt.StartsWith(key))
.FirstOrDefault();
if (line == null) return string.Empty;
var result = line.linetxt;
for (int i = line.index + 1; i < lines.Length; i++)
{
if (!keys.Any(a => lines[i].StartsWith(a)))
result += lines[i];
else
break;
}
return result;
}
// get single Line Item before spesic key if the Line is not a key
string getLinebefore(string the_after_key)
{
var the_after_line = lines
.Select((linetxt, index) => new { linetxt, index })
.Where(w => w.linetxt.StartsWith(the_after_key))
.FirstOrDefault();
if (the_after_line == null) return string.Empty;
var the_before_line_text = lines[the_after_line.index - 1];
//not a key
if (!keys.Any(a => the_before_line_text.StartsWith(a)))
return the_before_line_text;
else
return null;
}
// 1st get item without key
var itemName = lines.FirstOrDefault();
removeLine(itemName);
var year = lines.Where(w => Regex.Match(w, KEY_YEAR_Regex).Success).FirstOrDefault();
removeLine(year);
var companyName = getLinebefore(KEY_AFTER_COMPANY_NAME);
removeLine(companyName);
//2nd get item with Keys
var ingredients = getMultiLine(KEY_INGREDIENTS);
var contanins = getMultiLine(KEY_CONTAINS);
var allergenInfromation = getMultiLine(KEY_ALLERGEN_INFORMATION);
var description = getMultiLine(KEY_DESCRPTION);
var storageConditions = getMultiLine(KEY_STORAGE_CONDITION);
var shelfLife = getMultiLine(KEY_SHELFLIFE);
var itemNo = getMultiLine(KEY_ITEM_NO);
var bulk = getMultiLine(KEY_BULK);
var supplier = getMultiLine(KEY_SUPPLIER);
var warning = getMultiLine(KEY_WARNING);
// 3rd log
log("ItemName", itemName);
log("Ingredients", ingredients);
log("contanins", contanins);
log("Allergen Infromation", allergenInfromation);
log("Year", year);
log("Description", description);
log("Storage Conditions", storageConditions);
log("Shelf Life", shelfLife);
log("CompanyName", companyName);
log("Item No", itemNo);
log("Bulk", bulk);
log("Supplier", supplier);
log("warning", warning);
Console.ReadLine();
}
}
}
会输出
ItemName => BFFPPB10 黑巧克力澳洲坚果 11 盎司（312 克）
成分 => 成分：黑巧克力（糖、巧克力、可可
黄油、无水乳脂、大豆卵磷脂、香草）、澳洲坚果、
海盐。
contanins => 包含：澳洲坚果、牛奶、大豆。
过敏原信息 => 过敏原信息：可能包含其他树
坚果、花生、鸡蛋和小麦。
年份 => 2019 年 1 月 11 日
描述 => 描述：干烤的盐渍澳洲坚果
黑巧克力。
储存条件 => 储存条件：常温储存
湿度小于 50% 的温度。
保质期 => 保质期：12 个月
CompanyName => Blain's Farm & Fleet
货号 => 货号：701772
批量 => 批量：421172
供应商 => 供应商：Devon's
警告 =>