exinaris.com | Personal notes | Tutorials

Perform HTTP GET to get Html source

11/13/2011

HttpParams httpParameters = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(httpParameters,10000); // 10s max for connection
HttpConnectionParams.setSoTimeout(httpParameters, 5000); // 5s max to get data

HttpClient client = new DefaultHttpClient(httpParameters);
HttpGet request = new HttpGet(url); // url
HttpResponse response = null;
String html = "";
InputStream in = null;
try {
response = client.execute(request);

in = response.getEntity().getContent();

         BufferedReader reader = new BufferedReader(new InputStreamReader(in));
         StringBuilder str = new StringBuilder();

         String line = null;

        while((line = reader.readLine()) != null)
         {
                  str.append(line);
         }
         in.close();

html = str.toString();

} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

IMPORTANT: Add the following to the AndroidManifest.xml

<uses-permission android:name="android.permission.INTERNET"></uses-permission>

HashMap example

11/12/2011

HashMap<String, String> meMap=new HashMap<String, String>();

     meMap.put("Color1","Red");

     meMap.put("Color2","Blue");

     meMap.put("Color3","Green");

     meMap.put("Color4","White");



Get values:



Iterator myVeryOwnIterator = meMap.keySet().iterator();

while(myVeryOwnIterator.hasNext()) {

    String key=(String)myVeryOwnIterator.next();

    String value=(String)meMap.get(key);

    Toast.makeText(ctx, "Key: "+key+" Value: "+value, Toast.LENGTH_LONG).show();

}

Push/Pull from Emulator in Eclipse

11/10/2011

Open command prompt and navigate to C:\Program Files\Android\android-sdk\platform-tools or any where else the android-sdk is install.
Run the following commands:

adb pull source

[destination]



source e.x./sdcard/somefile.ext



destination e.x C:\

Download and install developing tools

8/22/2011

Windows Phone SDK 7.1 Beta 2
Download the Windows Phone SDK 7.1 Beta 2

Windows Phone Developer Tools 7.0
Visit http://create.msdn.com/en-us/home/getting_started and click Install image in "download the free tools" section or click this direct link. This is a smart installer that only downloads and installs the components you need to complete your development enironment. The full installation package includes:

Visual Studio 2010 Express
XNA Game Studio 4.0
Windows Phone Emulator
Microsoft Expression Blend for Windows Phone
Silverlight
.NET Framework 4

After the above installation you should install the October 2010 update to the Windows Phone Developer Tools which includes:

Windows Phone Connect Tool – Allows you to connect your phone to a PC when Zune® software is not running and debug applications that use media APIs.
Windows Phone Capability Detection Tool – Detects the phone capabilities used by your application.
Updated Bing Maps Silverlight Control – Includes improvements to gesture performance when using Bing™ Maps Silverlight® Control.

Infinite Scrolling with jQuery & ASP .NET

5/29/2011

If you want to find out how you can append data from the server to a web page asynchronously as the user scrolls to the bottom of the page, creating an “infinite scrolling”,then follow this post. Basically this is a functionality that you see in facebook’s News Feed and other popular sites.

Continue reading from original blog post

Read input text from the Console(2)

2/4/2011

Import the following libraries:
import java.util.Scanner;

Use the following code:
Scanner sc = new Scanner(System.in);
String input = sc.nextLine();

Read input text from the Console

2/4/2011

You need to import the following libraries
import java.io.BufferedReader;
import java.io.IOException;

Use the following code
InputStreamReader is = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(is);
System.out.println("Enter some text");
String input = br.readLine();

Generate RSS Feed using SyndicationFeed

1/11/2011

We split the procedure in two sections and actually in two different files. In the first section we create a Generic Handler where a user can call the file and display the Feed and in the second section we create a method to be called from the Generic handler that produces the actual feed items.

1. Add a Generic handler (.ashx) file to the project:

The code generated in the newly created file defines two parts of the IHttpHandler interface. The ProcessRequest(HttpContext context) method will be invoked whenever the file is requested or pointed to. Change the code as followed here:

public void ProcessRequest (HttpContext context) {

// Define response content type

context.Response.ContentType = "application/rss+xml";

MemoryStream ms = new MemoryStream();

XmlWriter rssWriter = XmlWriter.Create(ms);

// Get feeds from GetFeeds() method in RssService class file

RssService.GetFeeds().WriteTo(rssWriter);

rssWriter.Close();

ms.Flush();

ms.Position = 0;

StreamReader sr = new StreamReader(ms,Encoding.UTF8);

context.Response.Write(sr.ReadToEnd());

}

2. Add an empty class to your project (in this example we named it RssService.cs). Note that it might be added automatically in the App_Code folder of your project. Now add the following method:

public static Rss20FeedFormatter GetFeeds()

{

// SyndicationFeed object with title, description and feed alternate link

SyndicationFeed feed = new SyndicationFeed("My Blog Feed", "This is a test feed", new Uri(http://SomeURI));

feed.Authors.Add(new SyndicationPerson("someone@microsoft.com"));

feed.Categories.Add(new SyndicationCategory("How To Sample Code"));

feed.Description = new TextSyndicationContent("This is a how to sample that demonstrates how to expose a feed using RSS with WCF");

List<SyndicationItem> items = new List<SyndicationItem>();

// Query database

using (someDataClassesDataContext db = new someDataClassesDataContext())

{

var events = (from e in db.Events

orderby e.createdOn descending

select e).Take(10);

foreach (var curEvent in events)

{

// Create the Syndication Items/ the feed's items.

SyndicationItem item = new SyndicationItem(curEvent.name, curEvent.description, new Uri("http://www.someurl.com/Event.aspx?id=" + curEvent.eventId), curEvent.eventId.ToString(), curEvent.createdOn);

items.Add(item);

}

feed.Items = items;

}

return new Rss20FeedFormatter(feed);

}

The Rss20FeedFormatter class serializes a System.ServiceModel.Syndication.SyndicationFeed instance to and from RSS 2.0 format.

In the above code, we use the method GetFeeds() located in the RssService class file to get the data we want to display as the items in the RSS Feed written to an XmlWriter.

Retain State when navigating through application's pages

1/10/2011

When a user navigates from one page to another it would be nice to "save" the progress of the page's controls. Let's say a user is writing in a TextBox and with a button navigates to another page. When he hits the Back button (or navigate with another button to previous page) the text written by the user should be still in the TextBox. Unfortunately the developer should deal with this functionality.

You can use the PhoneApplicationService State to accomplish this task.

Add the following namespace:

using Microsoft.Phone.Shell;

and use the following code:

PhoneApplicationService phoneAppService = PhoneApplicationService.Current;

// When leaving the page we save the textBox1 contents in the State with key "myValue"

protected override void OnNavigatedFrom(System.Windows.Navigation.NavigationEventArgs e)

{

phoneAppService.State["myValue"] = textBox1.Text;

base.OnNavigatedFrom(e);

}

// When navigating to the current page, we check if there is a key in the State named "myValue",

// extract the value and display it in the textBox1

protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)

{

object someObject;

if (phoneAppService.State.ContainsKey("myValue"))

{

if (phoneAppService.State.TryGetValue("myValue", out someObject))

{

textBox1.Text = someObject.ToString();

}

base.OnNavigatedTo(e);

}

NOTE: When the application is removed from memory (closed) the PhoneApplicationService State is also removed from memory. So we cannot save the value permanently but only when navigating through pages in the application. You can use Isolated Storage to save permanetly data for your applciation.

Get Started - Developer Resources (Silverlight)

1/10/2011

General Info:

Developer Tools

Refer to Download and install developing tools (Local post)

Learn (Tutorials & Videos):

MSDN: Getting started with Windows Phone
MSDN: Windows Phone Development
MSDN: Code Samples

Channel 9: Windows Phone 7 Development for Absolute Beginners: This video series will help aspiring Windows Phone 7 developers get started. You will learn how to build simple WP7 applications, such as a GPS aware note taking application and more!
Channel 9: Silverlight for Windows Phone
Channel 9: Videos on Windows Phone

App Hub: Windows Phone 7 Jump Start (Channel 9 videos by Windows Phone MVPs Robe Miles and Andy Wigley).
App Hub: Education content catalog

Silverlight.net: Getting started videos

E-books:

Microsoft Press ebook: Programming Windows Phone 7 download link

MessageBox

1/8/2011

You can display a MessageBox in the screen simply using the following:

MessageBoxResult res = MessageBox.Show("Do you want to add a new note?","Add a new note", MessageBoxButton.OKCancel);

if (res == MessageBoxResult.OK)}
{
// User pressed OK
}
else
{
// User pressed Cancel
}

Debug preprocessor expression

1/8/2011

Test and debug your application writing strings and viewing them in the Output Window when application is in debug mode.

You will need to add the following namespace:

using System.Diagnostics;

Add the following preprocessor expression:

public static void TraceAction(string message)

{

#if DEBUG

Debug.WriteLine("{0} : {1}", message, DateTime.Now.ToLongTimeString());

#endif

}

Links in Master Page

12/19/2010

In order to make the links in a Master Page get working you may use ResolveClientUrl Contol Method.

The problem. Why html links will not work?
Consider the following application structure:

The relative link <a href="/Account/Login.aspx">Login</a> is in the Master Page. when you view the Default.aspx page (that is in root folder) the link works fine beacuse the browser will look for a file named Login.aspx in the Account subfolder.

But when you view the content page GetStarted.aspx (that is not in the root folder) and click the link (or check the markup), you will notice that the browser is looking for a file named Login.aspx in an Account subfolder (but we are already in the Account subfolder) like /Account/Account/Login.aspx.

Solution:

<a href="/Account/Login.aspx">Login</a>

should be replace by:

<a href='<%= ResolveClientUrl("~/Account/Login.aspx") %>'>Login</a>