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首页 > 解决方案 > 我似乎无法理解此 C# 代码中用于从输入字段中计算字符的当前错误

c# - 我似乎无法理解此 C# 代码中用于从输入字段中计算字符的当前错误

问题描述

这是我的代码，任何帮助/建议都会有所帮助！提前致谢！

我正在创建一个计算输入字段中字符的表单。我想我大部分都写对了，但是我得到了一些错误：

这是错误列表。

代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Data;
using System.ComponentModel;
using System.Drawing;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Wk5Ch12Exer9
{
    public partial class Form1 : Form
    {
        String inputText = null;

        // How do I decide on below number?
        int[] charFrequency = new int[52];

        public Form1()
        {
            InitializeComponent();
        }

        private void richTextBox1_TextChanged(object sender, EventArgs e)
        {
            inputText = rtbInputArea.Text;
        }

        private void processLine(String strng)
        {
            if (strng.Equals(null))
                return;

            char[] current = strng.ToCharArray();

            for (int idx = 0; idx < current.Length; idx++)
            {
                try
                {
                    if (current[idx]>= 65 &&
                        current[idx] <= 90)
                    {
                        charFrequency[current[idx] - 65] += 1;
                    }
                    else if (current[idx] >= 97 &&
                             current[idx] <= 122)
                    {
                        charFrequency[current[idx] - 97 + 26] += 1;
                    }
                }
                catch (Exception)
                { 
                }
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            StringBuilder output = new StringBuilder("");
            String[] inp = inputText.Split('\n');

            for (int idx = 0; idx < inp.Length; idx++)
            {
                processLine(inp[idx]);
            }

            for (int ins = 0; ins < 26; ins++)
            {
                if (charFrequency[ins] != 0)
                {
                    output.Append("Frequency of " +
                        (char)(ins + 65) + " is: " +
                        charFrequency[ins] + "\n");
                }
            }

            for (int ins = 26; ins < charFrequency.Length; ins++)
            {
                if (charFrequency[ins] != 0)
                {
                    outputAppend("Frequency of " +
                        (char)(ins + 97 - 26) +
                        " is: " +
                        charFrequency[ins] + "\n");
                }
            }

            rtbOutputArea.Text = output.ToString();
        }

        private void btnClear_Click(object sender, EventArgs e)
        {
            rtbInputArea.Text = "";
            rtbOutputArea_TextChanged.Text = "";
            charFrequency = new int[52];
        }
    }
}

我真的非常迷失在我要做的事情上。我一直在谷歌上搜索，最终变得更加困惑。

标签： c#

解决方案

从字典开始：

var dict = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
            .ToDictionary(k=>k,k=>0);

检查字符串中的字符是否在字典中，如果是，则递增：

if (dict.ContainsKey(c))
{
  dict[c]+=1;
}

输出：

var s = dict
  .Where(k=>k.Value>0)
  .Select(k=>$"Frequency of {k.Key} is {k.Value}")
var output = string.Join("\n", s);

或使用 Linq GroupBy：

var strng = "This is just a test.";

var arr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
  .ToCharArray();
var g = strng
  .Where(arr.Contains)
  .GroupBy(s=>s)
  .OrderBy(s=>s.Key)
  .Select(s=>$"Frequency of {s.Key} is {s.Count()}");

var output = string.Join("\n", g);

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