CK's Notepad

[ASP.NET MVC]OData PageResult v4

發表於 2014-07-31 分類於 ASP.NET MVC Disqus：

1 2	ODataHttpRequestMessageExtensions.GetNextPageLink 和 ODataHttpRequestMessageExtensions.GetInlineCount 都過時了..

要改用

1 2	Request.ODataProperties().NextLink, Request.ODataProperties().TotalCount

ODataProperties 需要使用 System.Web.Http.OData.Extensions 或 System.Web.OData.Extensions 命名空間

[ASP.NET MVC]WebApi回傳值得表示

發表於 2014-07-31 分類於 ASP.NET MVC Disqus：

asp.net mvc webapi 2 提供了 IHttpActionResult 這個界面

這個界面的效果基本上是跟HttpResponseMessage是一樣的但是在回傳值的表示有些微的不一樣,以下是整理表

IHttpActionResult	HttpResponseMessage Request.CreateResponse(HttpStatusCode)
Ok()	HttpStatusCode.OK
InternalServerError()	HttpStatusCode.InternalServerError
NotFound()	HttpStatusCode.NotFound

more on http://msdn.microsoft.com/zh-tw/library/system.web.http.apicontroller_methods(v=vs.118).aspx

這樣子寫起來就乾淨很多了

[Web] Local Storage

發表於 2014-07-18 分類於 HTML Disqus：

javascript基本操作html5的 local storage方法

// set item val
window.localstorage.setItem(key,value);
window.localstorage.getItem(key);
window.localstorage.removeItem(key);
window.localstorage.clear();

如果要把array object存入到localstorage裡面，需要把object轉換成文字.所以可透過json的方法來處理

1 2	JSON.stringify(object); JSON.parse(value);

ref:

http://www.w3schools.com/html/html5_webstorage.asp

http://blog.roodo.com/rocksaying/archives/15967715.html

[參考] OData 101: Using the [NotMapped] attribute to exclude Enum properties

發表於 2014-07-08 分類於 Note Disqus：

使用OData時如果遇到model裡面有自訂欄位是資料庫不存在時，就會出現錯誤

解決方案請參閱此篇文章

OData 101: Using the [NotMapped] attribute to exclude Enum properties

[EF6] BulkInsert

發表於 2014-05-13 分類於 Entity Framework Disqus：

處理狀況

當要同一時間新增大量資料時，如果單純用EF的新增方式，速度會讓人吐血。所以需要透過BulkInsert的方式處理，但是又不想自己另外寫ado的方式處理，所以就要透過extenstion的方式，讓EF的功能加強一下

##安裝 EntityFramework.BulkInsert-ef6

Nuget

##參考文件

http://efbulkinsert.codeplex.com/

##(用法)Demo Code

using(context db = new context()){
     // 原本會用
     // db.tables.AddRange(entities);
     // 改用
     db.BulkInsert(entities);
     
     db.SaveChanges();
}

##執行結果 非常快速

[EF6] Entity Framework 6 Code First Migrations with Multiple Data Contexts (轉)

發表於 2014-05-05 分類於 Entity Framework Disqus：

Ref: http://www.dotnet-tricks.com/Tutorial/entityframework/2VOa140214-Entity-Framework-6-Code-First-Migrations-with-Multiple-Data-Contexts.html

如何動態產生Database

如果利用Code first的方式，搭配DbMigration即可完成工作

DBContext.cs

public class DemoContext : DbContext
    {
        public DemoContext() { }
        public DemoContext(string ConnectionString)
            : base(ConnectionString)
        {            
            Database.SetInitializer(new CustomInitializer());
            Database.Initialize(true);
        }        
        public DbSet<Blog> Blogs { get; set; }
    }

CustomInitializer.cs

using System;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using System.Data.Entity.Migrations;
using System.Data.Entity.Migrations.Infrastructure;
using System.Linq;

internal sealed class Configuration : DbMigrationsConfiguration<DemoContext>
{        
    public Configuration()
    {
        AutomaticMigrationsEnabled = true;
        MigrationsDirectory = @"Migration";
    }
  

    protected override void Seed(DemoContext context)
    {            
    }
}

class CustomInitializer : IDatabaseInitializer<DemoContext>
{
    public void InitializeDatabase(DemoContext context)
    {
        if (!context.Database.Exists() || !context.Database.CompatibleWithModel(false))
        {
            var configuration = new Configuration();
            configuration.TargetDatabase = new DbConnectionInfo(context.Database.Connection.ConnectionString, "System.Data.SqlClient");
            var migrator = new DbMigrator(configuration);                
            migrator.Update();                
        }
    }
}

client端

1 2	using (var db = new AtaBookContext(connection1)){} using (var db = new AtaBookContext(connection2)){}

connection1和connection2分別指到不同的資料庫，EF就會根據連線字串的設定產生相對應的資料庫

[ASP.NET MVC]HTMLHelper work with AngularJs

發表於 2014-05-01 分類於 ASP.NET MVC Disqus：

當要在htmlHelper裡面使用angularjs的屬性時, 原本的ng-model變成ng_model, 將 - 變成 _ 即可

例如:

@Html.DropDownList("dropdown", (IEnumerable<SelectListItem>)ViewBag.items, new { ng_model = "currentSelect", ng_change = "selectChanges()" })

會產生
<select id="dropdown" name="dropdown" ng-change="selectChanges()" ng-model="currentSelect">
  <options>something</options>*n
</select>

[C#]Design Pattern for .NET Programmers

發表於 2014-04-29 分類於 CSharp Disqus：

#NOTE: Youtube link: http://youtu.be/S8XL1L_1Lyw

Abstract Factory

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Patterns
{
    class Program
    {
        public static Object Create(string className, Dictionary<String, Object> values)
        {
            Type type = Type.GetType(className);
            Object instance = Activator.CreateInstance(type);
            foreach (var entry in values)
            {
                type.GetProperty(entry.Key).SetValue(instance, entry.Value, null);
            }
            return instance;
        }
        static void Main(string[] args)
        {
            Console.WriteLine(Create("Patterns.Book", new Dictionary<string, object>()
            {
                {"Title", "Some titles"},
                {"Pages", 100}
            }));

            Console.WriteLine(Create("Patterns.CD", new Dictionary<string, object>()
            {
                {"Title", "Some CD"},
                {"Volume", 12}
            }));           
        }
    }

    class Book
    {
        public string Title { get; set; }
        public int Pages { get; set; }
        public override string ToString()
        {
            return string.Format("Book {0} {1}", Title, Pages);
        }
    }

    class CD
    {
        public string Title { get; set; }
        public int Volume { get; set; }
        public override string ToString()
        {
            return string.Format("CD {0} {1}", Title, Volume);
        }
    }
}

Cascade Pattern

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Patterns
{
    class Program
    {

        static void Main(string[] args)
        {           
            // Sect I
            //Mailer mailer = new Mailer();
            //mailer.from("[email protected]");
            //mailer.to("[email protected]");
            //mailer.subject("subjeccccttt");
            //mailer.message("contents blah blah");
            //mailer.send();

            // Sect II- Cascade way
            new Mailer().from("[email protected]")
                        .to("[email protected]")
                        .subject("subjeccccttt")
                        .message("contents blah blah")
                        .send();
        }       
    }
    // Sect I
    //class Mailer
    //{
    //    public void to(string toAdrr) { }
    //    public void from(string fromAddr) { }
    //    public void subject(string sub){}
    //    public void message(string msg) { }
    //    public void send() { }
    //}

    // Sect II
    class Mailer
    {
        public Mailer to(string toAdrr) { return this; }
        public Mailer from(string fromAddr) { return this; }
        public Mailer subject(string sub) { return this; }
        public Mailer message(string msg) { return this; }
        public void send() { }
    }    
}

Pluggable Behavior

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Patterns
{
    class Program
    {
        static int totalValues(int[] values)
        {
            int total = 0;
            foreach (var value in values)
            {
                total += value;
            }
            return total;
        }
        static int totalEvenValues(int[] values)
        {
            int total = 0;
            foreach (var value in values)
            {
                if (value % 2 == 0) total += value;
            }
            return total;
        }
        static int totalOddValues(int[] values)
        {
            int total = 0;
            foreach (var value in values)
            {
                if (value % 2 != 0) total += value;
            }
            return total;
        }
        static int totalSelectValues(int[] values, Func<int, bool> selector)
        {
            int total = 0;
            foreach (var value in values)
            {                
                // pass value(first param) into function and return second param value
                if (selector(value)) total += value;
            }
            return total;
        }
        // 
        static void Main(string[] args)
        {
            int[] values = new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };

            Console.WriteLine(totalValues(values));
            Console.WriteLine(totalEvenValues(values));
            Console.WriteLine(totalOddValues(values));

            Console.WriteLine("==================");
            // re-write
            // define functioin in lambda format
            // ref: http://msdn.microsoft.com/zh-tw/library/bb397687(v=vs.110).aspx
            Console.WriteLine(totalSelectValues(values, (value) => true));
            Console.WriteLine(totalSelectValues(values, (value) => value % 2 == 0));
            Console.WriteLine(totalSelectValues(values, (value) => value % 2 != 0));
        }
    }
}

Execute Around Method Pattern

part1

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Patterns
{
    class Program
    {
        class Resource
        {
            public Resource()
            {
                Console.WriteLine("Creating...");
            }
            public void op1()
            {
                Console.WriteLine("op1...");
            }
            public void op2()
            {
                Console.WriteLine("op2...");
            }
            ~Resource()
            {
                Console.WriteLine("cleanup exensive resource");
            }

        }  
        public static void Main(string[] args)
        {
            {
                Resource resource = new Resource();
                resource.op1();
                resource.op2();
            }
            Console.WriteLine("out of the block");         
        }
    }
}

執行結果:

part2 (with using())

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Patterns
{
    class Program
    {
        class Resource : IDisposable
        {
            public Resource()
            {
                Console.WriteLine("Creating...");
            }
            public void op1()
            {
                Console.WriteLine("op1...");
            }
            public void op2()
            {
                Console.WriteLine("op2...");
            }
            ~Resource()
            {
                Clearnup();
            }
            public void Dispose()
            {
                Clearnup();
                GC.SuppressFinalize(this);
            }
            private void Clearnup()
            {
                Console.WriteLine("cleanup exensive resource");
            }
        }
        public static void Main(string[] args)
        {
            // this require class that implement IDisposable
            using (Resource resource = new Resource())
            {
                resource.op1();
                resource.op2();
            }
            Console.WriteLine("out of the block");
        }
    }
}

執行結果

part3 with Execute Around Method Pattern

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Patterns
{
    class Program
    {
        class Resource
        {
            //Call Resource class from here
            public static void Use(Action<Resource> block)
            {
                Resource resouce = new Resource();
                try
                {
                    block(resouce);
                }
                finally
                {
                    resouce.Clearnup();
                }
                
            }

            //change public to protected
            // can't new class in normal way : class _class = new class()
            protected Resource()
            {
                Console.WriteLine("Creating...");
            }
            
            public void op1()
            {
                Console.WriteLine("op1...");
            }
            public void op2()
            {
                Console.WriteLine("op2...");
            }
            
            private void Clearnup()
            {
                Console.WriteLine("cleanup exensive resource");
            }
        }
        public static void Main(string[] args)
        {            
            {
                Resource.Use(
                    (resource) =>
                    {
                        resource.op1();
                        resource.op2();
                    });                
            }
            Console.WriteLine("out of the block");
        }
    }
}

執行結果

[Android Studio]platform not found

發表於 2014-04-07 分類於 Android Disqus：

Ref from G+

Ater upgrading to AS 0.5.4 I am getting this error 「Failed to set up SDK Error:Module 『AndroinoTerm』: platform 『android-18』 not found」 while I already have android-18 installed. My sdk path is correctly setup and I am also able to run my project successfully. Does Anybody else having this issue ?

Solution: 1. Change sdk folder location 2. update sdk path in android studio 3. change back to original location 4. update sdk path setting in android studio again 5. problem solved

[ASP.NET MVC] 利用OData+EF做分頁

發表於 2014-03-19 分類於 ASP.NET MVC Disqus：

當網頁要讀取一個很大量的資料時，通常都會透過分頁的方式來顯示資料。如果透過WebApi+OData的特性來做分頁，作法很單純設定 WebApiConfig.cs

1 2	//加入 config.EnableQuerySupport();

假設原本的API寫法如下

[Route("api/Customer")]
public IEnumerable<customers> Getcustomers()
{            
   return db.customers.AsEnumerable();
}

改成

[Route("api/Customer")]        
public IQueryable<customers> Getcustomers()
{            
   return db.customers.AsQueryable();
}

那在client端要呼叫api的url中，在加上OData的查詢語法來取得所要的資料區段，來達成分頁的效果

指令	說明	範例
top	結果挑出最前面的幾筆	?$top=3
skip	略過幾筆。可用於分頁顯示	?$skip=10
orderby	排序	?$orderby=SupplierID,ProductID
filter	篩選
	gt : > , 大於	$filter=ProductID gt 10
	lt : < , 小於	$filter=ProductID lt 10
	ge : >=, 大於等於	$filter=ProductID ge 10
	le : <=, 小於等於	$filter=ProductID le 10
	eq : =, 等於	$filter=ProductID eq 10
	ne : <>, 不等於	$filter=ProductID ne 10

參考資料: http://msdn.microsoft.com/en-us/library/windowsazure/gg312156.aspx

如果要利用OData取得所有的資料筆數時，上述的寫法沒有辦法做到，所以要稍微改寫一下原本的寫法

[Route("api/Customer")]   
 public PageResult<customers> Getcustomers(ODataQueryOptions<customers> options)
     {           
         var results = options.ApplyTo(db.customers.AsQueryable());
         return new PageResult<customers>(
            results as IEnumerable<customers>, // Items
            Request.GetNextPageLink(), // NextPageLink
            Request.GetInlineCount()); // Count
     }

要傳入的東西是一樣的，但是回傳的結果會變成

{
   "Items":[data....],
   "NextPageLink": null,
   "Count": 12345
}

所以在接收時要再調整

當$filter的查詢欄位是guid時

所送出的值前面要加上 guid 的關鍵字

1	?$filter=field eq guid'<value>'