如何解决UWP如何将数据传递到数据库然后填充网格？
我在使用UWP时遇到了一些困难，想知道是否有人可以提供帮助？这里对C♯来说是很新的东西。
基本上，我有一个用于添加雇员的页面，我认为输入的数据应该从逻辑上发送到一个名为“ Person”的类，然后再添加到数据库中（但是我知道哈哈！）。然后，数据库需要在主页上填充网格。
因此，主要的两个问题是，如何使Person类中的数据填充DB，并依次填充主页上的网格？以及如何从其他页面向班级添加人员？
这就是我要尝试的地方：
这是我的Person Class的内容：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace TestApp2
{
using static DB;
class Person
{
public int PersonId { get; set; }
public int DepartmentId { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string Position { get; set; }
public string Address { get; set; }
public double PayratePH { get; set; }
public double Holiday { get; set; }
public string TaxCode { get; set; }
private List<String> Grab_Entries()
{
List<String> entries = new List<string>();
using (SqliteConnection db = new SqliteConnection("Filename=sqliteSample.db"))
{
db.Open();
SqliteCommand selectCommand = new SqliteCommand("SELECT First_Name from EmployeeTable",db);
SqliteDataReader query;
try
{
query = selectCommand.ExecuteReader();
}
catch (SqliteException)
{
//Handle error
return entries;
}
while (query.Read())
{
entries.Add(query.GetString(0));
}
db.Close();
}
return entries;
}
}
}
这是我的数据库课程：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Windows.UI.Xaml;
namespace TestApp2
{
public static class DB
{
private static SuspendingEventHandler App_Suspending;
public static void database()
{
Application.Current.Suspending += new SuspendingEventHandler(App_Suspending);
using (SqliteConnection db = new SqliteConnection("Filename=sqliteSample.db"))
{
//Creation of the database table
db.Open();
String tableCommand1 = "CREATE TABLE IF NOT EXISTS EmployeeTable (Employee_ID INTEGER PRIMARY KEY AUTOINCREMENT,First_Name NVARCHAR(20) NULL,Last_Name NVARCHAR(40) NULL,Address NVARCHAR(50) NULL,Position NVARCHAR(20) NULL,Pay_Rate DOUBLE NULL,Tax_Code NVARCHAR(10) NULL,Sex NVARCHAR(20),NI NVACHAR(10),Emergency_Details NVARCHAR(100)";
SqliteCommand createTable = new SqliteCommand(tableCommand1,db);
try
{
createTable.ExecuteReader();
}
catch (SqliteException)
{
//Do nothing
}
}
}
}
}
最后是我的主页。注释掉的部分是我在测试是否可以填充xaml网格（如果有帮助的话，我正在使用社区开发网格？https://docs.microsoft.com/en-us/windows/communitytoolkit/controls/datagrid_guidance/datagrid_basics）
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Popups;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;
// The Blank Page item template is documented at https://go.microsoft.com/fwlink/?LinkId=402352&clcid=0x409
namespace TestApp2
{
public class Department
{
public int DepartmentId { get; set; }
public string DepartmentName { get; set; }
}
//public class Person
//{
// public int PersonId { get; set; }
// public int DepartmentId { get; set; }
// public string FirstName { get; set; }
// public string LastName { get; set; }
// public string Position { get; set; }
// public string Address { get; set; }
// public double PayratePH { get; set; }
// public double Holiday { get; set; }
// public string TaxCode { get; set; }
//}
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class MainPage : Page
{
public List<Department> Departments { get; set; }
List<Person> persons;
public MainPage()
{
this.InitializeComponent();
persons = new List<Person>();
// Departments = new List<Department>
//{
// new Department {DepartmentId = 1,DepartmentName = "R&D"},// new Department {DepartmentId = 2,DepartmentName = "Finance"},// new Department {DepartmentId = 3,DepartmentName = "IT"}
//};
// persons = new List<Person>
//{
// new Person
// {
// PersonId = 1,DepartmentId = 3,FirstName = "Ronald",LastName = "Rumple",// Position = "Network Administrator",Address = "14 Malkie Avenue",Holiday = 20,// TaxCode = "LC455"
// },// new Person
// {
// PersonId = 2,DepartmentId = 1,FirstName = "Brett",LastName = "Banner",// Position = "Software Developer",Address = "4/L Long Terrace",PayratePH = 12.95,Holiday = 12.5,// new Person
// {
// PersonId = 3,DepartmentId = 2,FirstName = "Alice",LastName = "Anderson",// Position = "Accountant",Address = "56 Hemming Way",PayratePH = 10,Holiday = 19.9,// TaxCode = "LC455"
// }
//};
}
private async void searchEmployee_Click(object sender,RoutedEventArgs e)
{
await new MessageDialog("Test").ShowAsync();
}
private void rota_Click(object sender,RoutedEventArgs e)
{
this.Frame.Navigate(typeof(Rota));
}
private void emailEmployee_Click(object sender,RoutedEventArgs e)
{
this.Frame.Navigate(typeof(email));
}
private void addEmployee_Click(object sender,RoutedEventArgs e)
{
this.Frame.Navigate(typeof(AddEmployee));
}
}
}
解决方法
如何使Person类中的数据填充数据库，并依次填充主页上的网格
您创建的tableCommand1字符串并不完整，您需要像这样修改它：String tableCommand1 = "CREATE TABLE IF NOT EXISTS EmployeeTable (Employee_ID INTEGER PRIMARY KEY AUTOINCREMENT,First_Name NVARCHAR(20) NULL,Last_Name NVARCHAR(40) NULL,Address NVARCHAR(50) NULL,Position NVARCHAR(20) NULL,Pay_Rate DOUBLE NULL,Tax_Code NVARCHAR(10) NULL,Sex NVARCHAR(20),NI NVACHAR(10),Emergency_Details NVARCHAR(100))";
用于创建数据库的完整代码为：
public async static void database()
{
await ApplicationData.Current.LocalFolder.CreateFileAsync("sqliteSample.db",CreationCollisionOption.OpenIfExists);
string dbpath = Path.Combine(ApplicationData.Current.LocalFolder.Path,"sqliteSample.db");
using (SqliteConnection db = new SqliteConnection($"Filename={dbpath}"))
{
//Creation of the database table
db.Open();
String tableCommand1 = "CREATE TABLE IF NOT EXISTS EmployeeTable (Employee_ID INTEGER PRIMARY KEY AUTOINCREMENT,Emergency_Details NVARCHAR(100))";
SqliteCommand createTable = new SqliteCommand(tableCommand1,db);
try
{
createTable.ExecuteReader();
}
catch (SqliteException ee){}
}
}
当您要将Person的数据插入数据库时，我以first_name为例：
private void InsertData(object sender,RoutedEventArgs e)
{
string dbpath = Path.Combine(ApplicationData.Current.LocalFolder.Path,"sqliteSample.db");
using (SqliteConnection db = new SqliteConnection($"Filename={dbpath}"))
{
db.Open();
SqliteCommand insertCommand = new SqliteCommand();
insertCommand.Connection = db;
// Use parameterized query to prevent SQL injection attacks
insertCommand.CommandText = "INSERT INTO EmployeeTable VALUES (NULL,@First_Name);";
insertCommand.Parameters.AddWithValue("@First_Name","Hello");
insertCommand.ExecuteReader();
db.Close();
}
}
有关如何使用sqlite的更多详细信息，可以参考此document。
此外，当您想向网格显示新数据时，建议使用ObservableCollection类而不是List，当您从此类中插入或删除数据时，它将自动更新UI。 / p>
ObservableCollection<Person> persons;
public MainPage()
{
this.InitializeComponent();
persons = new ObservableCollection<Person>();
......
}
如何从其他页面添加人员
您可以声明一个公共静态属性来表示MainPage实例，然后可以直接调用公共方法来添加新的Person类。您可以将NavigationCacheMode设置为Enabled，在这种情况下，当您返回MainPage时，将缓存数据。例如：
MainPage.cs：
public MainPage()
{
this.InitializeComponent();
......
this.NavigationCacheMode = NavigationCacheMode.Enabled;
Current = this;
}
public static MainPage Current;
public void addMethod(Person p)
{
persons.Add(p);
}
SecondPage.cs：
private void AddNewData(object sender,RoutedEventArgs e)
{
//First add data to database like mainpage does
MainPage.Current.addMethod(person);
}
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