win10系统 sqlite3.dll丢失，在网上下载了一个放在windows-SysWOW64里，开机又显示图上的错误，怎么解决

发布网友 发布时间：2022-04-08 18:05

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懂视网 时间：2022-04-08 22:27

using System;
using System.Collections.Generic;
using System.Collections;
using System.Threading.Tasks;
using SQLite.Net;
using SQLite.Net.Async;
using Windows.Storage;
using System.Diagnostics;
using YunshouyiUWP.Model;

namespace YunshouyiUWP.Data
{
 public class SQLiteDBManager
 {
 private static SQLiteDBManager dbManager;

 /// <summary>
 /// construct function
 /// </summary>
 public SQLiteDBManager()
 {
  InitDBAsync();
 }

 /// <summary>
 /// get current instance
 /// </summary>
 /// <returns></returns>
 public static SQLiteDBManager Instance()
 {
  if (dbManager == null)
  dbManager = new SQLiteDBManager();
  return dbManager;
 }
 private static SQLiteAsyncConnection dbConnection;

 /// <summary>
 /// get current DBConnection
 /// </summary>
 /// <returns></returns>
 public async Task<SQLiteAsyncConnection> GetDbConnectionAsync()
 {
  if (dbConnection == null)
  {
  var path = await GetDBPathAsync();
  dbConnection = new SQLiteAsyncConnection(() => new SQLiteConnectionWithLock(new SQLite.Net.Platform.WinRT.SQLitePlatformWinRT(), new SQLiteConnectionString(path, true)));
  }
  return dbConnection;
 }

 /// <summary>
 /// insert a item 
 /// </summary>
 /// <param name="item">item</param>
 /// <returns></returns>
 public async Task<int> InsertAsync(object item)
 {
  try
  {
  var dbConnect = await GetDbConnectionAsync();
  return await dbConnect.InsertOrReplaceAsync(item);
  }
  catch (Exception ex)
  {
  Debug.WriteLine(ex.Message);
  return -1;
  }

 }

 /// <summary>
 /// insert lots of items
 /// </summary>
 /// <param name="items">items</param>
 /// <returns></returns>
 public async Task<int> InsertAsync(IEnumerable items)
 {
  try
  {
  var dbConnect = await GetDbConnectionAsync();
  return await dbConnect.InsertOrReplaceAllAsync(items);
  }
  catch (Exception ex)
  {
  Debug.WriteLine(ex.Message);
  return -1;
  }

 }

 /// <summary>
 /// find a item in database
 /// </summary>
 /// <typeparam name="T">type of item</typeparam>
 /// <param name="pk">item</param>
 /// <returns></returns>
 public async Task<T> FindAsync<T>(T pk) where T : class
 {
  try
  {
  var dbConnect = await GetDbConnectionAsync();
  return await dbConnect.FindAsync<T>(pk);
  }
  catch (Exception ex)
  {
  Debug.WriteLine(ex.Message);
  return null;
  }
 }

 /// <summary>
 /// find a collection of items
 /// </summary>
 /// <typeparam name="T">type of item</typeparam>
 /// <param name="sql">sql command</param>
 /// <param name="parameters">sql command parameters</param>
 /// <returns></returns>
 public async Task<List<T>> FindAsync<T>(string sql, object[] parameters) where T : class
 {
  try
  {
  var dbConnect = await GetDbConnectionAsync();
  return await dbConnect.QueryAsync<T>(sql, parameters);
  }
  catch (Exception ex)
  {
  Debug.WriteLine(ex.Message);
  return null;
  }
 }

 /// <summary>
 /// update item in table 
 /// </summary>
 /// <typeparam name="T">type of item</typeparam>
 /// <param name="item">item</param>
 /// <returns></returns>
 public async Task<int> UpdateAsync<T>(T item) where T : class
 {
  try
  {
  var dbConnect = await GetDbConnectionAsync();
  return await dbConnect.UpdateAsync(item);
  }
  catch (Exception ex)
  {
  Debug.WriteLine(ex.Message);
  return -1;
  }
 }

 /// <summary>
 /// update lots of items in table
 /// </summary>
 /// <typeparam name="T">type of item</typeparam>
 /// <param name="items">items</param>
 /// <returns></returns>
 public async Task<int> UpdateAsync<T>(IEnumerable items) where T : class
 {
  try
  {
  var dbConnect = await GetDbConnectionAsync();
  return await dbConnect.UpdateAllAsync(items);
  }
  catch (Exception ex)
  {
  Debug.WriteLine(ex.Message);
  return -1;
  }
 }
 /// <summary>
 /// delete data from table
 /// </summary>
 /// <typeparam name="T">type of item</typeparam>
 /// <param name="item">item</param>
 /// <returns></returns>
 public async Task<int> DeleteAsync<T>(T item) where T : class
 {
  try
  {
  var dbConnect = await GetDbConnectionAsync();
  return await dbConnect.DeleteAsync<T>(item);
  }
  catch (Exception ex)
  {
  Debug.WriteLine(ex.Message);
  return -1;
  }
 }

 /// <summary>
 /// delete all items in table
 /// </summary>
 /// <param name="t">type of item</param>
 /// <returns></returns>
 public async Task<int> DeleteAsync(Type t)
 {
  try
  {
  var dbConnect = await GetDbConnectionAsync();
  return await dbConnect.DeleteAllAsync(t);
  }
  catch (Exception ex)
  {
  Debug.WriteLine(ex.Message);
  return -1;
  }
 }
 /// <summary>
 /// get local path in application local folder
 /// </summary>
 /// <returns></returns>
 private async Task<string> GetDBPathAsync()
 {
  var file = await ApplicationData.Current.LocalFolder.GetFileAsync("db.sqlite");
  if (file == null)
  {
  var dbFile = await StorageFile.GetFileFromApplicationUriAsync(new Uri("ms-appx:///Data/db.sqlite"));
  file = await dbFile.CopyAsync(ApplicationData.Current.LocalFolder);
  }

  return file.Path;
 }

 /// <summary>
 /// init db 
 /// </summary>
 private static async void InitDBAsync()
 {
  try
  {
  var file = await ApplicationData.Current.LocalFolder.TryGetItemAsync("db.sqlite");
  if (file == null)
  {
   var dbFile = await StorageFile.GetFileFromApplicationUriAsync(new Uri("ms-appx:///Data/db.sqlite"));
   file = await dbFile.CopyAsync(ApplicationData.Current.LocalFolder);
   var dbConnect = new SQLiteAsyncConnection(() => new SQLiteConnectionWithLock(new SQLite.Net.Platform.WinRT.SQLitePlatformWinRT(), new SQLiteConnectionString(file.Path, true)));
   var result = await dbConnect.CreateTablesAsync(new Type[] { typeof(Fund), typeof(P2P) });
   Debug.WriteLine(result);
  }

  }
  catch (Exception ex)
  {
  Debug.WriteLine(ex.Message);

  }
 }


 }
}

使用方法

以查找数据为例，如下：

public async Task<List<Fund>> GetFundDataAsync()
 {
  var result = await SQLiteDBManager.Instance().FindAsync<Fund>("select * from main where Id=?", new string[] { Guid.NewGuid().ToString() });
  if (result != null)
  return result;
  return null;

 }

初始化数据库时可以一次性创建需要的表，我创建的表如下：

注意事项

1.要为项目引入SQLite.Net.Async-PCL以及VC++ runtime类库，如下：

2.具体操作SQLite方法请查看SQLite.Net项目详细说明，地址如下：

https://github.com/oysteinkrog/SQLite.Net-PCL

Win10手记-为应用集成SQLite(二)

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