我创建了一个允许座位预订的表单，它有两个下拉菜单和一个标签，可以更改显示他们预订的座位。当我按下重置按钮但是下拉菜单没有时，标签会重置，它们会保留在选定的座位上，例如一个菜单说“A”而另一个说“4”我需要这些才能重置为空白，任何人都可以帮忙吗？
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;
namespace courseworkTask3
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
if (comboBox1.SelectedIndex <= 0)
{
button1.Enabled = false;
}
else
{
button1.Enabled = true;
}
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
string temp = comboBox1.Text;
int dropBox1enter;
if (int.TryParse(temp, out dropBox1enter))
{
}
int i = 0;
int seatsFound = 0;
int maxFoundSeats = 0;
int maxFoundSeatsStart = 0;
int maxFoundSeatsEnd = 0;
bool[] rowA = new bool[10];
rowA[0] = true;
rowA[1] = true;
rowA[2] = false;
rowA[3] = false;
rowA[4] = false;
rowA[5] = true;
rowA[6] = true;
rowA[7] = false;
rowA[8] = false;
rowA[9] = false;
bool[] rowB = new bool[10];
rowB[0] = true;
rowB[1] = false;
rowB[2] = false;
rowB[3] = false;
rowB[4] = false;
rowB[5] = true;
rowB[6] = true;
rowB[7] = false;
rowB[8] = false;
rowB[9] = false;
bool[] rowC = new bool[10];
rowC[0] = true;
rowC[1] = false;
rowC[2] = false;
rowC[3] = false;
rowC[4] = false;
rowC[5] = true;
rowC[6] = true;
rowC[7] = false;
rowC[8] = false;
rowC[9] = false;
bool[] rowD = new bool[10];
rowD[0] = true;
rowD[1] = false;
rowD[2] = false;
rowD[3] = false;
rowD[4] = false;
rowD[5] = true;
rowD[6] = true;
rowD[7] = false;
rowD[8] = false;
rowD[9] = false;
bool[] rowE = new bool[10];
rowE[0] = true;
rowE[1] = false;
rowE[2] = false;
rowE[3] = false;
rowE[4] = false;
rowE[5] = true;
rowE[6] = true;
rowE[7] = false;
rowE[8] = false;
rowE[9] = false;
if (comboBox2.Text == "A")
{
while (i < 10 && maxFoundSeats < dropBox1enter)
{
if (rowA[i] == false)
{
seatsFound++;
if (seatsFound > maxFoundSeats)
{
maxFoundSeats = seatsFound;
maxFoundSeatsStart = 1 + i - seatsFound;
maxFoundSeatsEnd = i;
}
}
else
{
seatsFound = 0;
}
i++;
} if (maxFoundSeats == dropBox1enter)
{
label4.Text = "Booked for " + maxFoundSeats + " seat(s) in row A starting, seat " + maxFoundSeatsStart + " to seat " + maxFoundSeatsEnd + ".";
}
else
{
label4.Text = "The seats you have selected are unavailable. @The maximum available is " + maxFoundSeats + " in row A From " + maxFoundSeatsStart + " to " + maxFoundSeatsEnd + ".";
label4.Text = label4.Text.Replace("@", System.Environment.NewLine);
}
}
else
{
if (comboBox2.Text == "B")
{
while (i < 10 && maxFoundSeats < dropBox1enter)
{
if (rowB[i] == false)
{
seatsFound++;
if (seatsFound > maxFoundSeats)
{
maxFoundSeats = seatsFound;
maxFoundSeatsStart = 1 + i - seatsFound;
maxFoundSeatsEnd = i;
}
}
else
{
seatsFound = 0;
}
i++;
}
if (maxFoundSeats == dropBox1enter)
{
label4.Text = "Booked for " + maxFoundSeats + " seat(s) in row B starting, seat " + maxFoundSeatsStart + " to seat " + maxFoundSeatsEnd + ".";
}
else
{
label4.Text = "The seats you have selected are unavailable. @The maximum available is " + maxFoundSeats + " in row B From " + maxFoundSeatsStart + " to " + maxFoundSeatsEnd + ".";
label4.Text = label4.Text.Replace("@", System.Environment.NewLine);
}
}
else
{
if (comboBox2.Text == "C")
{
while (i < 10 && maxFoundSeats < dropBox1enter)
{
if (rowC[i] == false)
{
seatsFound++;
if (seatsFound > maxFoundSeats)
{
maxFoundSeats = seatsFound;
maxFoundSeatsStart = 1 + i - seatsFound;
maxFoundSeatsEnd = i;
}
}
else
{
seatsFound = 0;
}
i++;
}
if (maxFoundSeats == dropBox1enter)
{
label4.Text = "Booked for " + maxFoundSeats + " seat(s) in row C starting, seat " + maxFoundSeatsStart + " to seat " + maxFoundSeatsEnd + ".";
}
else
{
label4.Text = "The seats you have selected are unavailable. @The maximum available is " + maxFoundSeats + " in row C From " + maxFoundSeatsStart + " to " + maxFoundSeatsEnd + ".";
label4.Text = label4.Text.Replace("@", System.Environment.NewLine);
}
}
else
{
if (comboBox2.Text == "D")
{
while (i < 10 && maxFoundSeats < dropBox1enter)
{
if (rowD[i] == false)
{
seatsFound++;
if (seatsFound > maxFoundSeats)
{
maxFoundSeats = seatsFound;
maxFoundSeatsStart = 1 + i - seatsFound;
maxFoundSeatsEnd = i;
}
}
else
{
seatsFound = 0;
}
i++;
}
if (maxFoundSeats == dropBox1enter)
{
label4.Text = "Booked for " + maxFoundSeats + " seat(s) in row D starting, seat " + maxFoundSeatsStart + " to seat " + maxFoundSeatsEnd + ".";
}
else
{
label4.Text = "The seats you have selected are unavailable. @The maximum available is " + maxFoundSeats + " in row D From " + maxFoundSeatsStart + " to " + maxFoundSeatsEnd + ".";
label4.Text = label4.Text.Replace("@", System.Environment.NewLine);
}
}
else
{
if (comboBox2.Text == "E")
{
while (i < 10 && maxFoundSeats < dropBox1enter)
{
if (rowE[i] == false)
{
seatsFound++;
if (seatsFound > maxFoundSeats)
{
maxFoundSeats = seatsFound;
maxFoundSeatsStart = 1 + i - seatsFound;
maxFoundSeatsEnd = i;
}
}
else
{
seatsFound = 0;
}
i++;
}
if (maxFoundSeats == dropBox1enter)
{
label4.Text = "Booked for " + maxFoundSeats + " seat(s) in row E starting, seat " + maxFoundSeatsStart + " to seat " + maxFoundSeatsEnd + ".";
}
else
{
label4.Text = "The seats you have selected are unavailable. @The maximum available is " + maxFoundSeats + " in row E From " + maxFoundSeatsStart + " to " + maxFoundSeatsEnd + ".";
label4.Text = label4.Text.Replace("@", System.Environment.NewLine);
}
}
} //end E
} //end D
} //end C
}
}
private void dropBox1_SelectedIndexChanged(object sender, EventArgs e)
{
}
private void dropBox2_SelectedIndexChanged(object sender, EventArgs e)
{
if (comboBox1.Text != null && comboBox2.Text != null)
{
button1.Enabled = true;
}
}
private void button2_Click(object sender, EventArgs e)
{
label4.Text = "";
}
}
}
答案 0 :(得分：0)
正如@Rohit Prakash在你的问题的评论中指出的那样，将ComboBox的SelectedIndex设置为-1会将任何选择重置为Combobox：
（我假设“button2”是你的重置按钮，你应该更恰当地命名你的控件）
private void button2_Click(object sender, EventArgs e)
{
label4.Text = "";
comboBox1.SelectedIndex = -1;
comboBox2.SelectedIndex = -1;
}