Question

我正在开发一个使用.sqlitedb格式在Android手机上以离线模式显示地图的项目。我的文件类型与SO上的类似问题无关，我无法打开文件，当前编写的文件与具有相同问题但文件类型为.s3db的人相同，我做错了什么？

using System;
using System.Collections.Generic;
using System.Collections;
using System.Linq;
using System.Text;
using SQLite;
using SQLitePCL;
using System.Data;


using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.Graphics;
using System.Drawing;
using System.Runtime.Serialization.Formatters.Binary;
using System.IO;
using System.ComponentModel;

namespace MapplicationIII
{


public class TilesProvider : DataModel
{
    public SQLiteConnection db_con;
    public void Prepare() { }
    public sqlite3_stmt stmt;

public TilesProvider(String dbPath)
        {

            db_con = new SQLiteConnection(@"Data Source = [file path]\MapDataBase.sqlitedb;");

            //DataTable tables = db_con.GetTableInfo<db_con.GetTableInfo(string tiles_tb);

        }
}
}

我收到错误：

SQLite.SQLiteException：无法打开数据库文件

Answer 1

您可以查看名为“Tasky”的Xamarin示例项目

创建数据库：

    public SqliteConnection connection;
    public string path;
    static object locker = new object ();

    /// <summary>
    /// Initializes a new instance of the <see cref="Tasky.DL.TaskDatabase"/> TaskDatabase. 
    /// if the database doesn't exist, it will create the database and all the tables.
    /// </summary>
    public TaskDatabase (string dbPath) 
    {
        var output = "";
        path = dbPath;
        // create the tables
        bool exists = File.Exists (dbPath);

        if (!exists) {
            connection = new SqliteConnection ("Data Source=" + dbPath);

            connection.Open ();
            var commands = new[] {
                "CREATE TABLE [Items] (_id INTEGER PRIMARY KEY ASC, Name NTEXT, Notes NTEXT, Done INTEGER);"
            };
            foreach (var command in commands) {
                using (var c = connection.CreateCommand ()) {
                    c.CommandText = command;
                    var i = c.ExecuteNonQuery ();
                }
            }
        } else {
            // already exists, do nothing. 
        }
        Console.WriteLine (output);
    }

获取物品：

    public IEnumerable<Task> GetItems ()
    {
        var tl = new List<Task> ();

        lock (locker) {
            connection = new SqliteConnection ("Data Source=" + path);
            connection.Open ();
            using (var contents = connection.CreateCommand ()) {
                contents.CommandText = "SELECT [_id], [Name], [Notes], [Done] from [Items]";
                var r = contents.ExecuteReader ();
                while (r.Read ()) {
                    tl.Add (FromReader(r));
                }
            }
            connection.Close ();
        }
        return tl;
    }

通过这些示例，可以很容易地以相同的方式将其实现到您的应用程序中

如何在Visual Studio / Xamarin项目中打开.sqlitedb文件？

1 个答案: