XamarinSQLite教程在Xamarin.Android項目中使用數據庫

在Xamarin.Android項目中使用預設數據庫的具體操作步驟如下：

(1)創建一個Xamarin.Android項目，如AndroidSQLiteDemo。

(2)在AndroidSQLiteDemo項目的Resources文件夾下創建一個Raw文件夾。

(3)將上一節中創建的Documents.db數據庫拖動到Raw文件夾中。

(4)打開MainActivity.cs文件，將Documents.db數據庫的內容復制到/data/data/[your packageName/files/ MyDocuments.db中，代碼如下：

using System;

using Android.App;

using Android.Content;

using Android.Runtime;

using Android.Views;

using Android.Widget;

using Android.OS;

using Android.Support.V7.App;

using System.IO;

using System.Text;

namespace AndroidSQLiteDemo

{

[Activity(Label = "@string/app_name", MainLauncher = true, LaunchMode = Android.Content.PM.LaunchMode.SingleTop, Icon = "@drawable/icon")]

public class MainActivity : AppCompatActivity

{

protected override void OnCreate(Bundle bundle)

{

base.OnCreate(bundle);

SetContentView(Resource.Layout.main);

var toolbar = FindViewById(Resource.Id.toolbar);

if (toolbar != null)

{

SetSupportActionBar(toolbar);

SupportActionBar.SetDisplayHomeAsUpEnabled(false);

SupportActionBar.SetHomeButtonEnabled(false);

}

// Get our button from the layout resource,

// and attach an event to it

var clickButton = FindViewById(Resource.Id.my_button);

clickButton.Click += (sender, args) =>

{

var sqliteFilename = "MyDocuments.db";

string documentsPath = System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal); // Documents folder

var path = Path.Combine(documentsPath, sqliteFilename);

Console.WriteLine("數據庫文件的目錄：{0}",path);

if (!File.Exists(path))

{

var s = Resources.OpenRawResource(Resource.Raw.Documents);

//創建寫入列

FileStream writeStream = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Write);

ReadWriteStream(s, writeStream);

}

};

}

void ReadWriteStream(Stream readStream, Stream writeStream)

{

int Length = 256;

Byte[] buffer = new Byte[Length];

int bytesRead = readStream.Read(buffer, 0, Length);

//?寫入所需字節

while (bytesRead > 0)

{

writeStream.Write(buffer, 0, bytesRead);

bytesRead = readStream.Read(buffer, 0, Length);

}

readStream.Close();

writeStream.Close();

}

}

}

運行程序后，初始狀態如圖1.31所示。

輕拍HELLO WORLD,CLICK ME!按鈕后，會在輸出窗口輸出以下的內容：

數據庫文件的目錄：/data/user/0/com.company.AndroidSQLiteDemo/files/MyDocuments.db

此時Documents.db數據庫中的內容就會復制到MyDocuments.db文件中。