c# - 我正在尝试在上传到数据库之前验证用户输入。我已链接我的验证和主代码，但我一直收到错误
问题描述
错误：
System.FormatException: '输入字符串的格式不正确。'
我让用户输入表单，但在接受之前必须对其进行验证（以 开头IsFilledIn()）。我已将表单中文本框中的字符串解析为 int，以便它可以进入数据库。当我点击提交时，它似乎完全跳过了验证，但已经包含了所有需要的内容（我认为）。
当前代码：
表格1：
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using Lab5_validation;
using System.Data.SqlClient;
namespace FinalAJG
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void btnsubmit_Click(object sender, EventArgs e)
{
Character temp = new Character();
//Sets temporary Variables
temp.CharName = txtCharName.Text;
temp.Health = Int32.Parse(txtHealth.Text);
temp.Lvl = Int32.Parse(txtLvl.Text);
temp.Agility = Int32.Parse(txtAgility.Text);
temp.Strength = Int32.Parse(txtStrength.Text);
temp.Stamina = Int32.Parse(txtStamina.Text);
temp.Armor = Int32.Parse(txtArmor.Text);
temp.HoursPlayed = Double.Parse(txtHoursPlayed.Text);
temp.PlayedSince = DateTime.Parse(txtPlayedSince.Text);
temp.Cass = txtClass.Text;
if (!temp.Feedback.Contains("ERROR:"))
{
Feedback.Text = temp.AddARecord();
}
else
{
Feedback.Text = temp.Feedback;
}
}
}
}
字符.cs：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data;
using System.Data.SqlClient;
using Lab5_validation;
namespace FinalAJG
{
class Character
{
//Define PRIVATE variables.
bool blnResult;
private string charname;
private string cass;
private int health;
private int lvl;
private int agility;
private int strength;
private int stamina;
private int armor;
private double hoursplayed;
private DateTime playedsince;
private float AvgPlayTime=777;
private int TotalPoints=444;
public string feedback = "";
// Creates Public variables the users can input to, then stores them to private variable if validated correctly.
public string CharName
{
get
{
//Returns private variable to class.
return charname;
}
set
{
//IF-ELSE statement to validate user input.
if (ValidationLibrary.IsItFilledIn(value))
{
// Sets private variable 'fName' to equal user input on public variable.
charname = value;
}
else
{
//If they enter invalid input, the feed back will be set to an error message, and the private variable will not be set.
feedback += "\n\nERROR: Enter your charcters name!!!";
}
}
}
//Public variable to receive user input securly.
public string Cass
{
get
{
//Returns Private variable
return cass;
}
set
{ //IF-ELSE statement to validate user input.
if (ValidationLibrary.IsItFilledIn(value))
{
cass = value; // Sets Private Variable
}
else
{//Feedback gives error IF validation
feedback += "\n\nERROR: Enter your Class!(ONLY OPTIONS ARE, Mage, Assassin, Warrior, Archer, Druid, and Warlock!!";
}
}
}
//Same as previous Public Variables
public int Health
{
get
{
return health;
}
set
{ //Checks for user input, if not true give error feedback.
if (ValidationLibrary.IsItFilledIn(value.ToString()))
{
health = value;
}
else
{
feedback += "\n\nERROR: Enter Characters Health (25-100)!! ";
}
}
}
//Same as previous Public Variables
public int Lvl
{
get
{
return lvl;
}
set
{
if (ValidationLibrary.IsItFilledIn(value.ToString()))
{
lvl = value;
}
else
{
feedback += "\n\nERROR:Enter your Characters level! (1-80)\n ";
}
}
}
//Same as previous Public Variables, except it will not be required to fill it in.
public int Agility
{
get
{
return agility;
}
set
{
if (ValidationLibrary.IsItFilledIn(value.ToString()))
{
agility = value;
}
else
{
feedback += "\n\nERROR:Enter valid Date!! (02-20-2020, 11/11/2011, 06/24/2019)";
}
}
}
//Same as previous Public Variables
public int Strength
{
get
{
return strength;
}
set
{
//Validates to ensure the required length of zipcode is entered
if (ValidationLibrary.IsItFilledIn(value.ToString()))
{
do
{
strength = value;
} while (blnResult == true);
}
else
{
feedback += "\n\nERROR:Enter Characters strength!! (1-25) ";
}
}
}
//Same as previous Public Variables
public int Stamina
{
get
{
return stamina;
}
set
{
if (ValidationLibrary.IsItFilledIn(value.ToString()))
{
stamina = value;
}
}
}
//Same as previous Public Variables except the validation checks for valid characters and the correct length
public int Armor
{
get
{
return armor;
}
set
{
if (ValidationLibrary.IsItFilledIn(value.ToString()))
{
armor = value;
}
else
{
feedback += "\n\nERROR:Enter Valid armor rating!! (10-50) ";
}
}
}
//Same as previous Public Variables
public double HoursPlayed
{
get
{
return hoursplayed;
}
set
{
if (ValidationLibrary.IsItFilledIn(value.ToString()))
{
hoursplayed = value;
}
else
{
feedback += "\n\nERROR:Enter Valid Number!!(.5, 2.3, 6.4, 92)";
}
}
}
//Same as previous Public Variables except checks for required characters for a valid Email.
public DateTime PlayedSince
{
get
{
return playedsince;
}
set
{
if (ValidationLibrary.IsItFilledIn(value.ToString()))
{
playedsince = value;
}
else
{
feedback += "\n\nERROR:Enter valid Date!! (02-20-2020, 11/11/2011, 06/24/2019)";
}
}
}
// Feedback variable to display results or error message.
public string Feedback
{
get
{
return feedback;
}
set
{ // IF feedback contains 'ERROR' then leave it blank and display which input was incorrect
if (feedback.Contains("ERROR:"))
{
feedback += "";
}
//ELSE, store and display the results.
else
{
feedback = value;
}
}
}
public string AddARecord()
{
//Init string var
string strResult = "";
//Make a connection object
SqlConnection Conn = new SqlConnection();
//Initialize it's properties
Conn.ConnectionString = ********************";//Set the Who/What/Where of DB
//Sends command to SQL Server
string strSQL = "INSERT INTO Chars (CharName, Class, Health, Lvl, Agility, Strength, Stamina, Armor, HoursPlayed, PlayedSince, AvgPlayTime, TotalPoints) VALUES (@CharName, @Class, @Health, @Level, @Agility, @Strength, @Stamina, @Armor, @HoursPlayed, @PlayedSince, @AvgPlayTime, @TotalPoints)";
// Sends out Command
SqlCommand comm = new SqlCommand();
comm.CommandText = strSQL; //Commander knows what to say
comm.Connection = Conn; //Where's the phone? Here it is
// Adds all parameters.
comm.Parameters.AddWithValue("@CharName", CharName);
comm.Parameters.AddWithValue("@Class", Cass);
comm.Parameters.AddWithValue("@Health", Health);
comm.Parameters.AddWithValue("@Level", Lvl);
comm.Parameters.AddWithValue("@Agility", Agility);
comm.Parameters.AddWithValue("@Strength", Strength);
comm.Parameters.AddWithValue("@Stamina", Stamina);
comm.Parameters.AddWithValue("@Armor", Armor);
comm.Parameters.AddWithValue("@HoursPlayed", HoursPlayed);
comm.Parameters.AddWithValue("@PlayedSince", PlayedSince);
comm.Parameters.AddWithValue("@AvgPlayTime", AvgPlayTime);
comm.Parameters.AddWithValue("@TotalPoints", TotalPoints);
//Attempts to connect to the Database server
try
{
//Calls to the database server, like dialing a phone.
Conn.Open();
int intRecs = comm.ExecuteNonQuery();
//Output to rhe user the success of inserting records
strResult = $"SUCCESS: Inserted {intRecs} records.";
//Close the Connection to Database Server
Conn.Close();
}
//This will catch any errors if we run into issues connecting.
catch (Exception err)
{
//Displays The Error.
strResult = "ERROR: " + err.Message;
}
finally
{
}
return strResult;
}
public DataSet SearchPerson(String strCharName, String strCharID)
{
//Create a dataset to return filled
DataSet ds = new DataSet();
//Create a command for our SQL statement
SqlCommand comm = new SqlCommand();
//Write a Select Statement to perform Search
String strSQL = "SELECT CharID, CharName, Class, Health, Level, Agility, Strength, Armor, HoursPlayed, PlayedSince, AvgPlayTime, TotalPoints FROM Chars WHERE 0=0";
//If the First/Last Name is filled in include it as search criteria
if (strCharName.Length > 0)
{
strSQL += " AND CharName LIKE @CharName";
comm.Parameters.AddWithValue("@CharName", "%" + strCharName + "%");
}
if (strCharID.Length > 0)
{
strSQL += " AND CharID LIKE @CharID";
comm.Parameters.AddWithValue("@CharID", "%" + strCharID + "%");
}
//Create DB tools and Configure
//*********************************************************************************************
SqlConnection conn = new SqlConnection();
//Create the who, what where of the DB
string strConn = @GetConnected();
conn.ConnectionString = strConn;
//Fill in basic info to command object
comm.Connection = conn; //tell the commander what connection to use
comm.CommandText = strSQL; //tell the command what to say
//Create Data Adapter
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = comm; //commander needs a translator(dataAdapter) to speak with datasets
//*********************************************************************************************
//Get Data
conn.Open(); //Open the connection (pick up the phone)
da.Fill(ds, "Chars_Temp"); //Fill the dataset with results from database and call it "EBooks_Temp"
conn.Close(); //Close the connection (hangs up phone)
//Return the data
return ds;
}
private string GetConnected()
{
return ************************
}
// Initialize Public Class from person().
public Character()
{
charname = "";
cass = "";
health = 25;
lvl = 1;
agility = 1;
strength = 1;
stamina = 1;
armor = 10;
hoursplayed = 0;
playedsince = DateTime.Now;
feedback = "";
}
}
}
验证：
//Allen J. Gawlowicz
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Lab5_validation
{
public class ValidationLibrary
{
bool result = false;
string temp;
//Validates for alphabetical input only.
public static bool Goodchar(string temp)
{
bool result = false;
string strGoodChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
// FOR EACH charcacter in Variable, check to make sure it is Alphabetical
foreach (char ch in strGoodChars.ToUpper())
{//If the variable contains only alphabetical, result= true.
if (temp.Contains(ch))
{
result = true;
}
}
return result;
}
//Checks to see if user inputs a bad word.
public static bool GotBadWords(string temp)
{
bool result = false;
//Array which holds all bad words to ever exist!!
string[] strBadwords = { "POOP", "HOMEWORK", "CACA" };
// FOR EACH word in the array it checks to see if input value matches.
foreach (string strBW in strBadwords)
{
if (temp.Contains(strBW))
{
result = true;
}
}
return result;
}
//Function which checks if user inputs.
public static bool IsItFilledIn(string temp)
{
bool result = false;
//If the number of characters entered is greater than 0 (then obviously), it is filled in (true).
if (temp.Length > 0)
{
result = true;
}
return result;
}
//Function which checks if user input is a future date.
public static bool IsAFutureDate(DateTime temp)
{
bool blnResult;
//IF usrr input is today or before, then blnRes = false.
if (temp <= DateTime.Now)
{
blnResult = false;
}
else
{
blnResult = true;
}
return blnResult;
}
//Function which checks user email input for '@' and '.'.
public static bool IsValidEmail(string temp)
{
bool blnResult = true;
int atLocation = temp.IndexOf("@");
int NexttatLocation = temp.IndexOf("@", atLocation + 1);
int periodLocation = temp.LastIndexOf(".");
if (temp.Length < 8)
{
blnResult = false;
}
else if (atLocation < 2)
{
}
else if (periodLocation + 2 > (temp.Length))
{
blnResult = false;
}
return blnResult;
}
//Function which checks for '.' in the input URL.
public static bool IsValidUrl(string temp)
{
bool blnResult = true;
int NexttatLocation = temp.IndexOf(".");
int periodLocation = temp.LastIndexOf(".");
if (temp.Length < 10)
{
blnResult = false;
}
else if (periodLocation + 2 > (temp.Length))
{
blnResult = false;
}
return blnResult;
}
//Function which checks user input for a specific length. ('min' will changed depending on variable in main program).
public static bool IsMinimumAmount(string temp, int min)
{
bool blnResult;
if (temp.Length >= min)
{
blnResult = true;
}
else
{
blnResult = false;
}
return blnResult;
}
public static bool IsMinimumAmount(double temp, double min)
{
bool blnResult;
if (temp >= min)
{
blnResult = true;
}
else
{
blnResult = false;
}
return blnResult;
}
}
}
程序.cs：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;
using Lab5_validation;
namespace FinalAJG
{
static class Program
{
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
}
}
解决方案
您的Parse方法不能接受空字符串。相反，我建议TryParse，它将尝试解析字符串，如果失败，那么您将获得分配目标的默认值。所以如果你这样做：
int.TryParse(txtHealth.Text, out temp.Health);
的值temp.Health将是字符串的解析值，或者它将是默认值（即0for int）。
double和可以使用相同的方法DateTime，因此：
double.TryParse(txtHoursPlayed.Text, out temp.HoursPlayed);
DateTime.TryParse(txtPlayedSince.Text, out temp.PlayedSince);
或者，您可以检查输入字符串IsNullOrWhiteSpace是否为true：
temp.Health = string.IsNullOrWhiteSpace(txtHealth.Text) ? 0 : int.Parse(txtHealth.Text);
但当然，这些TryParse方法通常更清洁。
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