英文:
how to display data in ascending order of a text file c#
问题
我需要按照项目编号的升序对我的代码进行排序并显示。以下是示例代码：
string data = $"{itemNumber}|{itemName}|{itemPrice}";
using (StreamWriter writer = File.AppendText("items.txt"))
{
writer.WriteLine(data);
}
public void DisplayItemList()
{
using (StreamReader reader = new StreamReader("items.txt"))
{
Console.WriteLine("\n ---------------------------------");
Console.WriteLine(" Item No. Item Name Price");
Console.WriteLine(" ---------------------------------");
List<string> itemLines = new List<string>();
while (!reader.EndOfStream)
{
string line = reader.ReadLine();
itemLines.Add(line);
}
itemLines.Sort(); // 对项目行进行排序
foreach (string line in itemLines)
{
string[] fields = line.Split('|');
Console.WriteLine(String.Format(" {0,-13}{1,-16}{2,0}", fields[0], fields[1], fields[2]));
}
Console.Write("\n");
}
}
这里是我的示例代码。如你所见，我有：
1 - oslopaper | 34 - bond | 11 - art
我希望它变成：
1 - oslopaper, 11 - art, 最后是 34 - bond
因为我想按升序排列。
英文:
i need to sort and display my code by ascending order based off on the item number. Here's the sample code.
string data = $"{itemNumber}|{itemName}|{itemPrice}";
using (StreamWriter writer = File.AppendText("items.txt"))
{
writer.WriteLine(data);
}
public void DisplayItemList()
{
using (StreamReader reader = new StreamReader("items.txt"))
{
Console.WriteLine("\n ---------------------------------");
Console.WriteLine(" Item No. Item Name Price");
Console.WriteLine(" ---------------------------------");
while (!reader.EndOfStream)
{
string line = reader.ReadLine();
string[] fields = line.Split('|');
Console.WriteLine(String.Format(" {0,-13}{1,-16}{2,0}", fields[0], fields[1], fields[2]));
}
Console.Write("\n");
}
}
here's my sample code. as you can see i have
1 - oslopaper | 34 - bond | 11 - art
I needed it to be
1 - oslopaper, 11 - art, lastly, 34 - bond
because I wanted it to be in ascending order.
答案1
得分: 2
建议使用 *Linq* 来查询文件（在这里可以添加排序 - `OrderBy`；表示 - `Select`；标题 - `Prepend`）：
```csharp
using System.Linq;
using System.IO;
...
public void DisplayItemList() {
var result = File
.ReadLines("items.txt")
.Where(line => !string.IsNullOrWhiteSpace(line)) // 为了更安全
.Select(line => line.Split('|'))
.OrderBy(fields => int.Parse(fields[0]))
.Select(fields => $" {fields[0],-13}{fields[1],-16}{fields[2],0}")
.Prepend(" --------------------------------- ")
.Prepend(" Item No. Item Name Price ")
.Prepend(" --------------------------------- ");
Console.Write(string.Join(Environment.NewLine, result));
}
<details>
<summary>英文:</summary>
I suggest *querying* file with a help of *Linq* (here you can add ordering - `OrderBy`; representing - `Select`, headers - `Prepend`):
using System.Linq;
using System.IO;
...
public void DisplayItemList() {
var result = File
.ReadLines("items.txt")
.Where(line => !string.IsNullOrWhiteSpace(line)) // to be on the safer side
.Select(line => line.Split('|'))
.OrderBy(fields => int.Parse(fields[0]))
.Select(fields => $" {fields[0],-13}{fields[1],-16}{fields[2],0}")
.Prepend(" --------------------------------- ")
.Prepend(" Item No. Item Name Price ")
.Prepend(" --------------------------------- ");
Console.Write(string.Join(Environment.NewLine, result));
}
</details>
# 答案2
**得分**: 0
你可以使用LINQ在显示之前对项目进行排序。
```csharp
var lines = File.ReadAllLines("items.txt")
.OrderBy(line => int.Parse(line.Split('|')[0]));
英文:
you can sort items before displaying them by LINQ
var lines = File.ReadAllLines("items.txt")
.OrderBy(line => int.Parse(line.Split('|')[0]));
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