我正在创建一个扑克统计WinForm程序，用于将玩家信息和8周的奖金以及总奖金金额写入文件并阅读该信息以显示在表单中。我在阅读每周8个奖金数量的文本框到我的阵列时遇到了问题。我收到“未设置为对象实例的对象引用”。错误。我在下面的代码中注意到我认为错误的来源。我已经包含了表单代码和我的类代码。我有什么想法我做错了吗？我希望我已经提供了足够的问题背景。在此先感谢!!
我的表单代码：
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Runtime.Serialization.Formatters.Binary;
using System.Runtime.Serialization;
using System.Text;
using System.Windows.Forms;
namespace PokerStats
{
public partial class FormPokerStats : Form // FormPokerStats inheriting from class Form
{
// declaring and assigning of variables needed for file read/write
const char DELIM = ',';
const string FILEPATH = @"C:\C# Project Output\";
const string FILENAME = "PokerPlayers.txt";
// declaring instances of Person, Location, and Winnings classes
Person myplayer = new Person();
Location mycasino = new Location();
Winnings mywinnings = new Winnings();
// constructing in/out FileStream/StreamReader/StreamWriter objects
static FileStream inFile = new FileStream(FILEPATH + FILENAME, FileMode.OpenOrCreate, FileAccess.Read, FileShare.ReadWrite);
StreamWriter writer = new StreamWriter(outFile);
static FileStream outFile = new FileStream(FILEPATH + FILENAME, FileMode.Append, FileAccess.Write, FileShare.ReadWrite);
StreamReader reader = new StreamReader(inFile);
public FormPokerStats()
{
InitializeComponent();
}
// "Enter/Update Player" tab Enter Player button: read/assign user input, write to file, close file stream
private void buttonEnterPlayer_Click(object sender, EventArgs e)
{
// if directory does not exist, create it
if (!(Directory.Exists(FILEPATH)))
{
// create directory
Directory.CreateDirectory(FILEPATH);
}
try
{
// read user input and assign to variables; test for empty player inputs and reprompt for input, if necessary
// Player Information fields
// if any or all textboxes are left blank
if ((textBoxSSN.Text == String.Empty || textBoxFirstName.Text == String.Empty || textBoxLastName.Text == String.Empty
|| textBoxCasinoName.Text == String.Empty || textBoxCasinoState.Text == String.Empty) ||
(textBoxSSN.Text == String.Empty && textBoxFirstName.Text == String.Empty && textBoxLastName.Text == String.Empty
&& textBoxCasinoName.Text == String.Empty && textBoxCasinoState.Text == String.Empty))
{
MessageBox.Show("Please complete all player information fields.", "Input Error!");
}
else
{
// if all textboxes are completed, assign to variables
myplayer.SocialSecurityNumber = textBoxSSN.Text;
myplayer.FirstName = textBoxFirstName.Text;
myplayer.LastName = textBoxLastName.Text;
mycasino.CasinoName = textBoxCasinoName.Text;
mycasino.CasinoState = textBoxCasinoState.Text;
// writing record to text file
writer.WriteLine(myplayer.ToString() + mycasino.ToString());
// if record is successfully written, display messagebox
MessageBox.Show("Wrote " + myplayer.FirstName.ToString() + ' ' + myplayer.LastName.ToString() + " to file with winnings totaling " + mywinnings.TotalWinnings.ToString("C2") + ".", "File Written");
}
***************************ERROR HERE***************************
// read weekly winnings input and assign to appropriate array position; test for empty inputs and assign default value of 0 if empty
// Week1
if (textBoxWeek1Winnings.Text == String.Empty)
{
mywinnings.ReadWinningsIntoArray("0", 0);
}
else mywinnings.ReadWinningsIntoArray(textBoxWeek1Winnings.Text, 0);
//// Week2
//if (textBoxWeek2Winnings.Text == String.Empty)
//{
// mywinnings.ReadWinningsIntoArray("0", 1);
//}
//else mywinnings.ReadWinningsIntoArray(textBoxWeek2Winnings.Text, 1);
//// Week3
//if (textBoxWeek3Winnings.Text == String.Empty)
//{
// mywinnings.ReadWinningsIntoArray("0", 2);
//}
//else mywinnings.ReadWinningsIntoArray(textBoxWeek3Winnings.Text, 2);
//// Week4
//if (textBoxWeek2Winnings.Text == String.Empty)
//{
// mywinnings.ReadWinningsIntoArray("0", 3);
//}
//else mywinnings.ReadWinningsIntoArray(textBoxWeek1Winnings.Text, 3);
//// Week5
//if (textBoxWeek2Winnings.Text == String.Empty)
//{
// mywinnings.ReadWinningsIntoArray("0", 4);
//}
//else mywinnings.ReadWinningsIntoArray(textBoxWeek1Winnings.Text, 4);
//// Week6
//if (textBoxWeek2Winnings.Text == String.Empty)
//{
// mywinnings.ReadWinningsIntoArray("0", 5);
//}
//else mywinnings.ReadWinningsIntoArray(textBoxWeek1Winnings.Text, 5);
//// Week7
//if (textBoxWeek2Winnings.Text == String.Empty)
//{
// mywinnings.ReadWinningsIntoArray("0", 6);
//}
//else mywinnings.ReadWinningsIntoArray(textBoxWeek1Winnings.Text, 6);
//// Week8
//if (textBoxWeek2Winnings.Text == String.Empty)
//{
// mywinnings.ReadWinningsIntoArray("0", 7);
//}
//else mywinnings.ReadWinningsIntoArray(textBoxWeek1Winnings.Text, 7);
//// calculate total winnings by summing WeeklyWinnings array values and assigning to TotalWinnings
//mywinnings.TotalWinnings = mywinnings.WeeklyWinnings.Sum();
}
catch (FormatException)
{
// if format exception is thrown in try, display messagebox with message
MessageBox.Show("Winnings must be entered at xx.xx (e.g. 34.56).", "Input Error!");
}
catch (Exception f)
{
// if exception is thrown in try, display messagebox with message
MessageBox.Show(f.Message, "Error!");
}
// clear form textboxes
ClearTextBoxes();
writer.Close();
}
// "Enter/Update Player" tab Exit button: closes file streams and quits the application
private void buttonExit_Click(object sender, EventArgs e)
{
// closing file streams
reader.Close();
inFile.Close();
writer.Close();
outFile.Close();
// close application
Application.Exit();
}
// "Player List" tab View Player Winnings button: read file records, display records sorted by total winnings descending
private void buttonRead_Click(object sender, EventArgs e)
{
// if file exists
if (!(File.Exists(FILEPATH + FILENAME)))
{
// if file does not exist, display messagebox
MessageBox.Show("File does not exist.", "File Does Not Exist!");
}
else
{
string[] fields;
// read first record in file
string recordIn = reader.ReadLine();
listBoxOutputRecords.Items.Add("First Name\tLast Name\tCasino Name\tCasino State\tTotal Winnings\t");
while (recordIn != null)
{
// split record into array and assign
fields = recordIn.Split(DELIM);
myplayer.SocialSecurityNumber = fields[0];
myplayer.FirstName = fields[1];
myplayer.LastName = fields[2];
mycasino.CasinoName = fields[3];
mycasino.CasinoState = fields[4];
// output record to listbox
listBoxOutputRecords.Items.Add(myplayer.FirstName + "\t\t" + myplayer.LastName + "\t\t" + mycasino.CasinoName + "\t\t" + mycasino.CasinoState + "\t\t");
// read next record in file
recordIn = reader.ReadLine();
}
}
// return file position to 0
inFile.Seek(0, SeekOrigin.Begin);
}
// "Player List" tab Exit button: call buttonExit_Click method
private void buttonExit2_Click(object sender, EventArgs e)
{
// call buttonExit_Click method
buttonExit_Click(sender, e);
}
// method to clear listbox items when "Player List" tab is left
private void tabPagePlayerList_Leave(object sender, EventArgs e)
{
// clear listbox items
listBoxOutputRecords.Items.Clear();
}
// method to clear textbox controls
private void ClearTextBoxes()
{
Action<Control.ControlCollection> func = null;
func = (controls) =>
{
foreach (Control control in controls)
if (control is TextBox)
(control as TextBox).Clear();
else
func(control.Controls);
};
func(Controls);
}
}
}
我的班级代码：
class Person
{
// SocialSecurityNumber, FirstName, LastName properties
public string SocialSecurityNumber { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
// overridden ToString() method to return string output
public override string ToString()
{
return (SocialSecurityNumber + ',' + FirstName + ',' + LastName + ',');
}
}
// Location class
class Location
{
// CasinoName and CasinoState properties
public string CasinoName { get; set; }
public string CasinoState { get; set; }
// overridden ToString() method to return string output
public override string ToString()
{
return (CasinoName + ',' + CasinoState + ',');
}
}
// Winnings class
class Winnings
{
double[] weeklyWinnings = new double[8];
// WeeklyWinnings and TotalWinnings properties
public double[] WeeklyWinnings { get; set; }
public double TotalWinnings { get; set; }
// overridden ToString() method to return string output
public override string ToString()
{
return ( WeeklyWinnings[0].ToString("C2") + ','
+ WeeklyWinnings[1].ToString("C2") + ','
+ WeeklyWinnings[2].ToString("C2") + ','
+ WeeklyWinnings[3].ToString("C2") + ','
+ WeeklyWinnings[4].ToString("C2") + ','
+ WeeklyWinnings[5].ToString("C2") + ','
+ WeeklyWinnings[6].ToString("C2") + ','
+ WeeklyWinnings[7].ToString("C2") + ','
+ TotalWinnings.ToString("C2"));
}
// method to read textbox winnings inputs into the array
public void ReadWinningsIntoArray(string textBoxText, int position)
{
double value;
if (double.TryParse(textBoxText, out value))
WeeklyWinnings[position] = Convert.ToDouble(value);
}
}
答案 0 :(得分：0)
是否在设计器文件中正确定义了textBoxWeek1Winnings？如果不是，则null是因为此变量未在任何地方定义，这就是问题。
我认为在表单的设计视图中，您应该能够看到奖金的文本框名称，这是您未正确设置的内容。在声明一个新的文本框
Dotnetperls有一个例子，可能有助于考虑你如何编码，因为我认为你在这里错过了一些相对简单的东西。
答案 1 :(得分：0)
您可以使用File.ReadAllLines()和File.WriteAllLines()方法大大简化您的代码。