Question

我是Xamarin的新人。我想学习基本的插入功能。当我开始点击按钮时我收到了未处理的异常。我认为我的Path文件夹是对的。我不知道我犯了什么错。希望你们能帮我解决这个问题。谢谢你提前。

NewTravelPage.xaml.cs

using SQLite;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using TravelRecordApp.Model;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;

namespace TravelRecordApp
{
    [XamlCompilation(XamlCompilationOptions.Compile)]
    public partial class NewTravelPage : ContentPage
    {
        public NewTravelPage ()
        {
            InitializeComponent ();
        }

        public void ToolBarItem_Clicked(Object sender, EventArgs e)
        {
            Post post = new Post()
            {
                Experience = experienceEntry.Text
            };

            SQLiteConnection connection = new SQLiteConnection(App.DatabaseLocation);
            connection.CreateTable<Post>();

            int rows = connection.Insert(post);

            connection.Close();

            if (rows > 0)
            {
                DisplayAlert("Success", "Experience successfully inserted", "OK!");
            }
            else
            {
                DisplayAlert("Failed", "Experience failed to inserted", "ok!");
            }
        }

    }
}

MainActivity.cs（Android文件夹）

using System;

using Android.App;
using Android.Content.PM;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using System.IO;

namespace TravelRecordApp.Droid
{
    [Activity(Label = "TravelRecordApp", Icon = "@drawable/icon", Theme = "@style/MainTheme", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
    public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
    {
        protected override void OnCreate(Bundle bundle)
        {
            TabLayoutResource = Resource.Layout.Tabbar;
            ToolbarResource = Resource.Layout.Toolbar;

            base.OnCreate(bundle);

            global::Xamarin.Forms.Forms.Init(this, bundle);

            string fileName = "travel_db.sqlite";
            string folderPath = System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal);
            string fullPath = Path.Combine(folderPath, fileName);

            LoadApplication(new App(fullPath));
        }
    }
}

Answer 1

SQLiteConnection需要connectionString，而不仅仅是数据库的路径。

你正在传递：

/data/data/com.companyname.TravelRecordApp/files/travel_db.sqlite

预期传递：

Data Source=/data/data/com.companyname.TravelRecordApp/files/travel_db.sqlite

试试这一行：

SQLiteConnection connection = new SQLiteConnection("Data Source=/data/data/com.companyname.TravelRecordApp/files/travel_db.sqlite");

Answer 2

传递数据库路径时，需要正确传递连接字符串（而不仅仅是DB文件的路径）。

例如：

SQLiteConnection connection = new SQLiteConnection("Data Source=C:\\PATH_TO_DB\db.sqlite;");

Sqlite未处理的异常xamarin

2 个答案: