我对C＃编程很新，并且在查明如何执行此操作时遇到了一些麻烦。我想在程序中说如果textBoxes未填写streamWriter而不是messageBox，则不应向文件发送任何内容并弹出messageBox。截至目前，只有if ((fileOut != null))弹出，但信息仍然被发送到文件。我正在尝试使用类似using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
// Calculate payroll
private void btnCalculate_Click(object sender, EventArgs e)
{
try
{
decimal hoursWorked;
decimal hourlyPayRate;
decimal basePay;
decimal overtimeHours;
decimal overtimePay;
decimal grossPay;
// Get the hours worked and hourly pay rate.
hoursWorked = decimal.Parse(txtHoursWorked.Text);
hourlyPayRate = decimal.Parse(txtHourlyRate.Text);
// Determine the gross pay.
if (hoursWorked >= 40)
{
// Calculate the base pay (without overtime).
basePay = hourlyPayRate * 40;
// Calculate the number of overtime hours.
overtimeHours = hoursWorked - 40;
// Calculate the overtime pay.
overtimePay = overtimeHours * hourlyPayRate * 1.5m;
// Calculate the gross pay.
grossPay = basePay + overtimePay;
}
else
{
// Calculate the gross pay.
grossPay = hoursWorked * hourlyPayRate;
}
// Display the gross pay.
lblGrossPay.Text = Convert.ToString(grossPay);
}
catch (Exception ex)
{
// Display an error message.
MessageBox.Show(ex.Message);
} //Writes text to files
StreamWriter fileOut = new StreamWriter("employeePay.dat", true);
//if (!(fileOut != null))//I am trying this. However stated this way nothing is passed to the file
{
fileOut.Write(txtName.Text);
fileOut.Write(",");
fileOut.Write(txtNumber.Text);
fileOut.Write(",");
fileOut.Write(txtHourlyRate.Text);
fileOut.Write(",");
fileOut.Write(txtHoursWorked.Text);
fileOut.Write(",");
fileOut.WriteLine(lblGrossPay.Text);
}
fileOut.Close();
LoadContacts();
}
// Clear all text from output labels & input textboxes
private void btnClera_Click(object sender, EventArgs e)
{
// Clear the TextBoxes and gross pay label.
txtName.Text = "";
txtNumber.Text = "";
txtHoursWorked.Text = "";
txtHourlyRate.Text = "";
lblGrossPay.Text = "";
// Reset the focus.
//txtHoursWorked.Focus();
}
// End program
private void btnExit_Click(object sender, EventArgs e)
{
this.Close();
}
void LoadContacts()
{
try
{
lstEmployeePay.Items.Clear();
string employeePay;
if (File.Exists("employeePay.dat"))
{
StreamReader fileIn = new StreamReader("employeePay.dat");
while (!fileIn.EndOfStream)
{
employeePay = fileIn.ReadLine();
string[] fields = employeePay.Split(',');
lstEmployeePay.Items.Add(fields[0]);
lstEmployeePay.Items.Add(fields[1]);
lstEmployeePay.Items.Add(fields[2]);
lstEmployeePay.Items.Add(fields[3]);
lstEmployeePay.Items.Add(fields[4]);
lstEmployeePay.Items.Add("");
}
fileIn.Close();
}
}
catch (FileNotFoundException ex)
{
MessageBox.Show("The file does not exist, please try again");
}
catch (Exception ex)
{
}
}
}
}
之类的东西，但是我找不到插入它的好地方，或者这是应该使用的东西。任何帮助将非常感激。谢谢！
{{1}}
答案 0 :(得分：0)
显示消息框后，您只需要一个return语句。像
MessageBox.Show("");
return;
我还想在此提出一些其他建议。
您可以通过
检查文本框是否为空如果（string.IsNullorWhiteSpace（yourtextboxt.text）
您应该使用decimal.tryparse进行解析。它不会抛出异常。
答案 1 :(得分：0)
你需要在异常处理中移动你的流编写器，因为catch仍然被执行后的所有内容。
我还会考虑将StreamWriter包装在using语句中，以保证在函数退出时它被关闭。
try
{
// other code here
using(var fileOut = new StreamWriter("employeePay.dat", true)
{
fileOut.Write(txtName.Text);
fileOut.Write(",");
fileOut.Write(txtNumber.Text);
fileOut.Write(",");
fileOut.Write(txtHourlyRate.Text);
fileOut.Write(",");
fileOut.Write(txtHoursWorked.Text);
fileOut.Write(",");
fileOut.WriteLine(lblGrossPay.Text);
}
}
catch(...)
{
MessageBox();
}
// any code after the catch will still execute