我是编程新手,我正在尝试创建一个包含子菜单内部的菜单。主菜单具有继续执行的所有选项,而子菜单具有针对每个插入的选项的CRUD。
但是我完成的子菜单(“动物”)都无法通过id方法进行可视化,并且对以下子菜单的crud方法也是如此。同样,当子菜单完成其任务时,它应返回到初始子菜单选项,允许通过按零返回主菜单。尽管我尝试以不同的方式做事,但这没有发生。我不确定是switch语句出错还是方法调用。
对不起,如果代码比平常大一点:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace menu
{
class Program
{
public static int id = 1;
enum animalHeader { id, name, client_name, type_animal };
enum clientHeader { id, name, client_surname, adrress };
static void Main(string[] args)
{
string[,] animal = new string[20, 4];
string[,] client = new string[20, 6];
do { MenuOptions(animal); } while (true);
}
static void MenuOptions(string[,] animal)
{
int userChoice;
do
{
Console.Clear();
Console.WriteLine("\nChoose one of the following options:\n");
Console.WriteLine("[ 1 ] Animals");
Console.WriteLine("[ 2 ] Clients");
Console.WriteLine("[ 0 ] Quit application\n");
} while (!int.TryParse(Console.ReadLine(), out userChoice) || userChoice < 0 || userChoice > 2);
Console.Clear();
switch (userChoice)
{
case 1:
menuAnimal(animal);
menuReturn(animal);
break;
case 2:
//menuClient(client);
mainMenu();
break;
case 0:
Environment.Exit(0);
break;
default:
Console.WriteLine("Try again!!");
break;
}
}
static void menuAnimal(string[,] animal)
{
int optAnimal;
do
{
Console.Clear();
Console.WriteLine("\nInsert one of the following options:\n");
Console.WriteLine("[ 1 ] Insert animal");
Console.WriteLine("[ 2 ] See animal");
Console.WriteLine("[ 3 ] Alter animal");
Console.WriteLine("[ 4 ] Erase animal");
Console.WriteLine("[ 5 ] List animals");
Console.WriteLine("[ 0 ] Return to main menu\n");
} while (!int.TryParse(Console.ReadLine(), out optAnimal) || optAnimal < 0 || optAnimal > 5);
Console.Clear();
switch (optAnimal)
{
case 1:
insertData(animal);
menuReturn(animal);
break;
case 2:
visualizeByid(animal);
menuReturn(animal);
break;
case 3:
updateById(animal);
menuReturn(animal);
break;
case 4:
deleteByid(animal);
menuReturn(animal);
break;
case 5:
listData(animal);
menuReturn(animal);
break;
}
}
static void mainMenu()
{
Console.Clear();
Console.ReadKey();
}
static void menuReturn(string[,] animal)
{
Console.Clear();
do { menuAnimal(animal); } while (true);
}
static int generateId()
{
return id++;
}
static int getInsertIndex(string[,] matrix)
{
for (int j = 0; j < matrix.GetLength(0) - 1; j++)
{
if (string.IsNullOrEmpty(matrix[j, 0])) return j;
}
return -1;
}
static void insertData(string[,] matrix)
{
int id = generateId();
int n = getInsertIndex(matrix);
matrix[n, 0] = Convert.ToString(id);
for (int j = 1; j < matrix.GetLength(1); j++)
{
do
{
Console.Write($"Insert {Enum.GetName(typeof(animalHeader), j)}: ");
matrix[n, j] = Console.ReadLine();
} while (String.IsNullOrEmpty(matrix[n, j]));
}
}
static int searchId(string[,] matrix)
{
int choosenId, index = -1;
do
{
Console.Write("Insert ID to continue: ");
} while (!int.TryParse(Console.ReadLine(), out choosenId));
for (int i = 0; i < matrix.GetLength(0); i++)
{
if (Convert.ToString(choosenId) == matrix[i, 0])
{
index = i;
}
}
return index;
}
static void visualizeByid(string[,] matrix)
{
int pos = searchId(matrix);
if (pos != -1)
{
for (int i = pos; i < pos + 1; i++)
{
for (int j = 0; j < matrix.GetLength(1); j++)
{
Console.Write($"{matrix[i, j]}\t");
}
Console.WriteLine();
}
}
else { Console.WriteLine("Wrong Id"); }
}
static void updateById(string[,] matrix)
{
int pos = searchId(matrix);
if (pos != -1)
{
for (int i = pos; i < pos + 1; i++)
{
for (int j = 1; j < matrix.GetLength(1); j++)
{
Console.Write($"Insert {Enum.GetName(typeof(animalHeader), j)}: ");
matrix[i, j] = Console.ReadLine();
}
Console.WriteLine();
}
}
else { Console.WriteLine("Id does not exist"); }
}
static void deleteByid(string[,] matrix)
{
int pos = searchId(matrix);
if (pos != -1)
{
for (int i = pos; i < pos + 1; i++)
{
for (int j = 0; j < matrix.GetLength(1); j++)
{
matrix[i, j] = null;
}
}
}
else { Console.WriteLine("Id does not exist"); }
}
static void listData(string[,] matrix)
{
for (int i = 0; i < matrix.GetLength(0); i++)
{
for (int j = 0; j < matrix.GetLength(1); j++)
{
Console.Write($"\t{matrix[i, j]}\t");
}
Console.WriteLine("\n\t");
}
}
}
}
答案 0 :(得分:0)
我可以发现的第一个问题是在menuAnimal
方法中。检查输入0时发生的情况,例如,使用调试器单步执行代码。
当用户输入0时,第一个do-while
条件通过(因为0是一个数字并且不小于0且不大于5),但是在下面的switch
语句中您没有case
的值为0,因此该方法停止执行,仅重绘,因为执行继续到menuReturn(animal);
中的MenuOptions
。
这里的下一个主要问题是menuReturn
方法。观察到一旦采用这种方法,就永远无法“逃脱”。无论发生什么情况,它始终会重新绘制动物菜单,并且while(true)
确保它会无限期地发生。因为里面没有break
条件,所以它将继续进行。
尽管您有很多选择,但我会在这里建议其他方法,因此您可以自由使用适合您的其他解决方案。
首先摆脱menuReturn
方法,并将此“菜单输出循环”放入菜单方法本身。在伪代码中,应为:
static void MenuMethod()
{
while (true)
{
userInput = read user input for example using do..while as in original code
goBack = false
switch (userInput)
{
case optionA:
doSomething();
goBack = true; //set go back to true if you want go up a level
break;
case optionSubmenu:
submenu(); //go to a submenu, which will start its own loop
//after submenu is closed (goBack = true), execution will return to this level
break;
}
if (goBack) return; //end execution of this menu
}
}
因此,在您的情况下,它看起来可能像这样:
static void MenuOptions(string[,] animal)
{
while (true)
{
int userChoice;
do
{
Console.Clear();
Console.WriteLine("\nChoose one of the following options:\n");
Console.WriteLine("[ 1 ] Animals");
Console.WriteLine("[ 2 ] Clients");
Console.WriteLine("[ 0 ] Quit application\n");
} while (!int.TryParse(Console.ReadLine(), out userChoice) || userChoice < 0 || userChoice > 2);
Console.Clear();
switch (userChoice)
{
case 1:
menuAnimal(animal);
break;
case 2:
//menuClient(client);
break;
case 0:
Environment.Exit(0);
break;
default:
Console.WriteLine("Try again!!");
break;
}
}
}
类似动物菜单:
static void MenuAnimal(string[,] animal)
{
while ( true )
{
int optAnimal;
do
{
Console.Clear();
Console.WriteLine("\nInsert one of the following options:\n");
Console.WriteLine("[ 1 ] Insert animal");
Console.WriteLine("[ 2 ] See animal");
Console.WriteLine("[ 3 ] Alter animal");
Console.WriteLine("[ 4 ] Erase animal");
Console.WriteLine("[ 5 ] List animals");
Console.WriteLine("[ 0 ] Return to main menu\n");
} while (!int.TryParse(Console.ReadLine(), out optAnimal) || optAnimal < 0 || optAnimal > 5);
Console.Clear();
bool goBack = false;
switch (optAnimal)
{
case 1:
insertData(animal);
break;
case 2:
visualizeByid(animal);
break;
case 3:
updateById(animal);
break;
case 4:
deleteByid(animal);
break;
case 5:
listData(animal);
break;
}
if ( goBack ) return;
}
}