[英]Local database with SQLite in Windows phone 8
我在Windows Phone 8中使用本地数据库创建了一个测试应用程序,但出现错误,我的项目无法创建我的sqlite数据库
你能帮助我吗 ?
运行时错误是这样的:
mscorlib.ni.dll中发生类型为'System.Reflection.TargetInvocationException'的异常,但未在用户代码中处理
附加信息:调用的目标已引发异常。
在这一行:val = m.GetValue(obj,null);
Person
:
namespace PhoneApp4
{
public class person
{
[SQLite.AutoIncrement , SQLite.PrimaryKey]
public int ID { get; set; }
public string FullName { get; set; }
}
}
mainpage.xaml.cs
:
namespace PhoneApp4
{
public partial class MainPage : PhoneApplicationPage
{
// Constructor
public MainPage()
{
InitializeComponent();
// Sample code to localize the ApplicationBar
//BuildLocalizedApplicationBar();
}
private async void BTO_save_Tap(object sender, System.Windows.Input.GestureEventArgs e)
{
SQLiteAsyncConnection conn = new SQLiteAsyncConnection(Path.Combine(ApplicationData.Current.LocalFolder.Path, "dbsqlite.sqlite"), true);
person person = new person
{
FullName = TB_save.Text
};
await conn.InsertAsync(person);
}
private async void BTO_search_Tap(object sender, System.Windows.Input.GestureEventArgs e)
{
SQLiteAsyncConnection conn = new SQLiteAsyncConnection(Path.Combine(ApplicationData.Current.LocalFolder.Path, "people.db"), true);
var query = conn.Table<person>().Where(x => x.ID == Convert.ToInt32(TB_search.Text));
var result = await query.ToListAsync();
foreach (var item in result)
{
LB_search.Items.Add(item.ID.ToString() + " " + item.FullName.ToString());
}
}
app.xaml.cs
:
private void Application_Launching(object sender, LaunchingEventArgs e)
{
string dbPath = Path.Combine(Windows.Storage.ApplicationData.Current.LocalFolder.Path, "dbsqlite.sqlite");
using (var db = new SQLiteConnection(dbPath))
{
db.CreateTable<person>();
}
}
// Code to execute when the application is activated (brought to foreground)
// This code will not execute when the application is first launched
private void Application_Activated(object sender, ActivatedEventArgs e)
{
string dbPath = Path.Combine(Windows.Storage.ApplicationData.Current.LocalFolder.Path, "dbsqlite.sqlite");
if (FileExists("dbsqlite.sqlite").Result)
{
using (var db = new SQLiteConnection(dbPath))
{
db.CreateTable<person>();
}
}
}
// Code to execute when the application is deactivated (sent to background)
// This code will not execute when the application is closing
private void Application_Deactivated(object sender, DeactivatedEventArgs e)
{
string dbPath = Path.Combine(Windows.Storage.ApplicationData.Current.LocalFolder.Path, "dbsqlite.sqlite");
if (!FileExists("dbsqlite.sqlite").Result)
{
using (var db = new SQLiteConnection(dbPath))
{
db.CreateTable<person>();
}
}
}
请参阅此示例http://code.msdn.microsoft.com/SQLite-for-Windows-Phone-8-8ff3beaf
private async void Application_Launching(object sender, LaunchingEventArgs e)
{
try
{
await ApplicationData.Current.LocalFolder.GetFileAsync("UniversityDB.db");
Connection = new SQLiteAsyncConnection("UniversityDB.db");
}
catch (FileNotFoundException)
{
DataService.CreateDbAsync();
}
}
和
public static async void CreateDbAsync()
{
App.Connection = new SQLiteAsyncConnection("UniversityDB.db");
var universityTask = App.Connection.CreateTableAsync<University>();
var studentTask = App.Connection.CreateTableAsync<Student>();
await Task.WhenAll(new Task[] { universityTask, studentTask });
}
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