LINQPad

string[] names = {"Michael", "Long"};

IEnumerable<string> query = names
.Where(n=>n.Contains("o"))
.OrderBy(n=>n.Length)
.Select(n=>n.ToUpper());

query.Dump();

// same query as above
IEnumerable<string>filtered = names.Where(n=>n.Contains("o"));
IEnumerable<string>sorted = filtered.OrderBy(n=>n.Length);
IEnumerable<string>finalQuery = sorted.Select(n=>n.ToUpper());

filtered.Dump("Filtered");
sorted.Dump("Sorted");
finalQuery.Dump("FinalQuery");

LINQ Dynamic Query

using System.Linq.Dynamic

var repository = new EmployeeRepository();

var query = repository.GetAll()
.AsQueryable()
.OrderBy("Name")
.Where("DepartmentID = 1");

LINQ Joins

var employeeRepository = new EmployeeRepository();
var departmentRepository = new DepartmentRepository();

Inner Join (Normal)

var employees =
from employee in employeeRepository.GetAll()
join department in departmentRepository.GetAll()
on employee.DepartmentID equals department.ID
select new {employee.Name, Department = department.Name};

Left Join (Grouping on Departments)

var query =
from d in departmentRepository.GetAll()
join e in employeesRepository.GetAll()
on d.ID equals e.DepartmentID
into ed
select new
{
Department = d.Name,
Employees = ed};

foreach(var group in query)
{
Console.WriteLine(group.Department);
foreach(var employee in group.Employees)
{
Console.WriteLine("\t" + employee.Name);
}
}

Cross Join (for completeness)

var employees =
from employee in employeeRepository.GetAll()
join department in departmentRepository.GetAll()
on employee.DepartmentID equals department.ID
select new {employee.Name, Department = department.Name};

LINQ Grouping and Projecting

var repository = new EmployeeRepository();

Comprehensive Query Syntax

var queryByDepartment =
from e in repository.GetAll()
group e by e.DepartmentID
into eGroup
orderby eGroup.Key descending
where eGroup.Key < 3
select new
{
DepartmentID = eGroup.Key,
Count = eGroup.Count(),
Employees = eGroup
};

Extension Methods with Lambda Expressions

var queryByDepartment2 =

repository.GetAll()

.GroupBy(e=>e.DepartmentID)

.OrderByDescending(g=>g.Key)

.Where(g=>g.Key < 3)

.Select(g=>

new

{

DepartmentID = g.Key,

Count = g.Count(),

Employees = g

});

foreach(var group in queryByDepartment2)
{

Console.WriteLine("DID: {0}, Count: {1}",

group.DepartmentID,

group.Count);

foreach(var employee in group.Employees)

{

Console.WriteLine("\t{0}:{1}", employee.DepartmentID, employee.Name);

}

}

Restrictions for Implicit Typing

The following var statements result in compiler errors:

var i;

var j, k = 0;

var n = null;

var number = "2";
int x = number + 1;

Extension Methods with Lambda Expressions vs. Comprehensive Query Syntax

Employee[] employees = new Employee[]
{
new Employee{ID=1, Name="The"},
new Employee{ID=2, Name="Foo"}
};

//Employee the = Array.Find(employees, FindThePredicate);
Employee the = Array.Find(employees, e=>e.Name == "The");

Comprehensive Query Syntax

Collection

IEnumerable<Employee> query1 =
from e in employees
where e.Name == "The"
orderby e.ID ascending
select e;

Single Item

Employee query1 =
(from e in employees
where e.Name == "The"
orderby e.ID ascending
select e).First();

Extension Methods with Lambda Expressions

Collection

IEnumerable<Employee> query2 =
employees.Where(e=>e.Name=="The")
.OrderBy(e=>e.ID)
.Select(e=>e);

Single Item

Employee query2 =
employees.Where(e=>e.Name=="The")
.OrderBy(e=>e.ID)
.Select(e=>e)
.First();

Action and Func Delegates and Lambda Expressions

private static void ActionAndFunc()
{
Action printEmptyLine = () => Console.WriteLine();
Action<int> printNumber = x => Console.WriteLine(x);
Action<int, int> printTwoNumbers = (x,y) =>
{
Console.WriteLine(x);
Console.WriteLine(y);
};

Func<DateTime> getTime = () => DateTime.Now;
Func<int, int> square = x => x*x;
Func<int, int, int> multiply = (x,y) => x*y;

printEmptyLine();
printNumber(6);
printTwoNumbers(2,3);

DateTime now = getTime();
int z = multiply(4,7);
}

Named vs. Anonymous Method vs. Lambda Expressions

Named Method Predicate - passing method pointers

static void Main(string[] args)
{
Employee the = Array.Find(employees, FindThePredicate);
}

static bool FindThePredicate(Employee e)
{
return e.Name == "The";
}

Anonymous Method

static void Main(string[] args)
{
Employee the = Array.Find(employees,
delegate(Employee e)
{
return e.Name == "The";
}
);
}

Lambda Expression - anonymous method but with less code

static void Main(string[] args)
{
Employee the = Array.Find(employees, (e) => e.Name =="The");
}

ReSharper is good for code cleanup and refactoring

Nghệ Sĩ App is in the Windows Phone Marketplace, officially!

Download link: http://www.windowsphone.com/en-US/apps/944dc164-0009-42af-941d-ba10b5241bed

Nghệ Sĩ App is in the Windows Phone Marketplace

FINALLY! :)

Windows Developer Camp

Signed up for the free all-day Windows Developer Camp in Reston, VA on Tuesday March 27. Link: https://msevents.microsoft.com/CUI/EventDetail.aspx?EventID=1032507574&Culture=en-US

Android GPS and Routing

Wrote a little Android program to find a route between the current GPS location and another pre-determined location (GMU) and display it on Android phone's built-in Google Maps.

Android Map View

main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/mainlayout"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <com.google.android.maps.MapView
        android:id="@+id/mapview"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:clickable="true"
        android:apiKey="useyourown"
    />

</RelativeLayout>

HelloMapViewActivity.java

package com.thekhuc.hellomapview;

import java.util.List;

import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;
import com.google.android.maps.OverlayItem;

import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.widget.LinearLayout;

public class HelloMapViewActivity extends MapActivity {
    LinearLayout linearLayout;
    MapView mapView;
    List<Overlay>mapOverlays;
    Drawable drawable;
    HelloItemizedOverlay itemizedOverlay;

/** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
     
        mapView = (MapView) findViewById(R.id.mapview);
        mapView.setBuiltInZoomControls(true);
     
        mapOverlays = mapView.getOverlays();
        drawable = this.getResources().getDrawable(R.drawable.androidmarker);
        itemizedOverlay = new HelloItemizedOverlay(drawable);
     
        GeoPoint point = new GeoPoint(19240000, -99120000);
        OverlayItem overlayitem = new OverlayItem(point, "","");
     
        itemizedOverlay.addOverlay(overlayitem);
        mapOverlays.add(itemizedOverlay);
    }

@Override
protected boolean isRouteDisplayed() {
// TODO Auto-generated method stub
return false;
}
 
}

HelloItemizedOverlay.java

package com.thekhuc.hellomapview;

import java.util.ArrayList;

import android.graphics.drawable.Drawable;

import com.google.android.maps.ItemizedOverlay;
import com.google.android.maps.OverlayItem;

public class HelloItemizedOverlay extends ItemizedOverlay<OverlayItem> {

private ArrayList<OverlayItem> mOverlays = new ArrayList<OverlayItem>();

public HelloItemizedOverlay(Drawable defaultMarker) {
super(boundCenterBottom(defaultMarker));
}

@Override
protected OverlayItem createItem(int i) {
return mOverlays.get(i);
}

@Override
public int size() {
return mOverlays.size();
}

public void addOverlay(OverlayItem overlay){
mOverlays.add(overlay);
populate();
}

}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.thekhuc.hellomapview"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="10" />
    <uses-permission android:name="android.permission.INTERNET"/>

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <uses-library android:name="com.google.android.maps"/>
        <activity
            android:name=".HelloMapViewActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Android Issue: java.lang.RuntimeException: Unable to instantiate activity ComponentInfo

Resolved.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.thekhuc.hellomapview"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="10" />
    <uses-permission android:name="android.permission.INTERNET"/>

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <uses-library android:name="com.google.android.maps"/>
        <activity
            android:name=".HelloMapViewActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Free Pluralsight Training TODAY Only

Check out their blog post for more information. I love Pluralsight!

App Submitted for Windows Marketplace

So excited!

Registering and Deploying to Windows Phone

How to: Register Your Phone for Development
How to: Use the Application Deployment Tool for Windows Phone

Thank You, Microsoft!

Microsoft was nice enough to give me App Hub 12-month membership for free. Now I can finally test and deploy the Windows Phone app. Thank you MS!

Android Hackbook and Facebook SDK

Hackbook is great for learning Facebook SDK and Android development.

Hackbook Place Check-in

final Intent myIntent = new Intent(getApplicationContext(), Places.class);

new AlertDialog.Builder(this)
.setTitle(R.string.get_location)
.setMessage(R.string.get_default_or_new_location)
.setPositiveButton(R.string.current_location_button,
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
myIntent.putExtra("LOCATION", "current");
startActivity(myIntent);
}
})
.setNegativeButton(R.string.times_square_button,
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
myIntent.putExtra("LOCATION", "times_square");
startActivity(myIntent);
}

}).show();

Hackbook Upload Photo

import android.provider.MediaStore;

final static int PICK_EXISTING_PHOTO_RESULT_CODE = 1;

dialog = ProgressDialog.show(Hackbook.this, "",
getString(R.string.please_wait), true, true);
new AlertDialog.Builder(this)
.setTitle(R.string.gallery_remote_title)
.setMessage(R.string.gallery_remote_msg)
.setPositiveButton(R.string.gallery_button,
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(Intent.ACTION_PICK,
(MediaStore.Images.Media.EXTERNAL_CONTENT_URI));
startActivityForResult(intent,
PICK_EXISTING_PHOTO_RESULT_CODE);
}

})
.setNegativeButton(R.string.remote_button,
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
/*
* Source tag: upload_photo_tag
*/  
Bundle params = new Bundle();
params.putString("url",
"http://www.facebook.com/images/devsite/iphone_connect_btn.jpg");
params.putString("caption",
"FbAPIs Sample App photo upload");
Utility.mAsyncRunner.request("me/photos", params,
"POST", new PhotoUploadListener(), null);
}

}).setOnCancelListener(new DialogInterface.OnCancelListener() {
@Override
public void onCancel(DialogInterface d) {
dialog.dismiss();
}
}).show();
}


@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
/*
* if this is the activity result from authorization flow, do a call
* back to authorizeCallback Source Tag: login_tag
*/

case AUTHORIZE_ACTIVITY_RESULT_CODE: {
Utility.mFacebook.authorizeCallback(requestCode, resultCode, data);
break;
}

/*
* if this is the result for a photo picker from the gallery, upload
* the image after scaling it. You can use the Utility.scaleImage()
* function for scaling
*/

case PICK_EXISTING_PHOTO_RESULT_CODE: {
if (resultCode == Activity.RESULT_OK) {
Uri photoUri = data.getData();
if (photoUri != null) {
Bundle params = new Bundle();
try {
params.putByteArray("photo",
Utility.scaleImage(getApplicationContext(), photoUri));
} catch (IOException e) {
e.printStackTrace();
}
params.putString("caption", "FbAPIs Sample App photo upload");
Utility.mAsyncRunner.request("me/photos", params, "POST",
new PhotoUploadListener(), null);
} else {
Toast.makeText(getApplicationContext(),
"Error selecting image from the gallery.", Toast.LENGTH_SHORT)
.show();
}
} else {
Toast.makeText(getApplicationContext(), "No image selected for upload.",
Toast.LENGTH_SHORT).show();
}
break;
}

//}
}



public class PhotoUploadListener extends BaseRequestListener {

        @Override
        public void onComplete(final String response, final Object state) {
            dialog.dismiss();
            mHandler.post(new Runnable() {
                @Override
                public void run() {
                    new UploadPhotoResultDialog(Hackbook.this, "Upload Photo executed", response)
                            .show();
                }
            });
        }

        public void onFacebookError(FacebookError error) {
            dialog.dismiss();
            Toast.makeText(getApplicationContext(), "Facebook Error: " + error.getMessage(),
                    Toast.LENGTH_LONG).show();
        }
    }

Hackbook Get Friends Graph API

dialog = ProgressDialog.show(Hackbook.this, "",
getString(R.string.please_wait), true, true);
new AlertDialog.Builder(this)
.setTitle(R.string.Graph_FQL_title)
.setMessage(R.string.Graph_FQL_msg)
.setPositiveButton(R.string.graph_button,
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
graph_or_fql = "graph";
Bundle params = new Bundle();
params.putString("fields", "name, picture, location");
Utility.mAsyncRunner.request("me/friends", params,
new FriendsRequestListener());
}

})
.setNegativeButton(R.string.fql_button,
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
graph_or_fql = "fql";
String query = "select name, current_location, uid, pic_square from user where uid in (select uid2 from friend where uid1=me()) order by name";
Bundle params = new Bundle();
params.putString("method", "fql.query");
params.putString("query", query);
Utility.mAsyncRunner.request(null, params,
new FriendsRequestListener());
}

}).setOnCancelListener(new DialogInterface.OnCancelListener() {
@Override
public void onCancel(DialogInterface d) {
dialog.dismiss();
}
}).show();


public class FriendsRequestListener extends BaseRequestListener {

        @Override
        public void onComplete(final String response, final Object state) {
            dialog.dismiss();
            Intent myIntent = new Intent(getApplicationContext(), FriendsList.class);
            myIntent.putExtra("API_RESPONSE", response);
            myIntent.putExtra("METHOD", graph_or_fql);
            startActivity(myIntent);
        }

        public void onFacebookError(FacebookError error) {
            dialog.dismiss();
            Toast.makeText(getApplicationContext(), "Facebook Error: " + error.getMessage(),
                    Toast.LENGTH_SHORT).show();
        }
    }

Hackbook Update Status

Bundle params = new Bundle();
params.putString("caption", getString(R.string.app_name));
params.putString("description", getString(R.string.app_desc));
params.putString("picture", Utility.HACK_ICON_URL);
params.putString("name", getString(R.string.app_action));

Utility.mFacebook.dialog(Hackbook.this, "feed", params, new UpdateStatusListener());
String access_token = Utility.mFacebook.getAccessToken();
System.out.println(access_token);


public class UpdateStatusListener extends BaseDialogListener {
        @Override
        public void onComplete(Bundle values) {
            final String postId = values.getString("post_id");
            if (postId != null) {
                new UpdateStatusResultDialog(Hackbook.this, "Update Status executed", values)
                        .show();
            } else {
                Toast toast = Toast.makeText(getApplicationContext(), "No wall post made",
                        Toast.LENGTH_SHORT);
                toast.show();
            }
        }

        @Override
        public void onFacebookError(FacebookError error) {
            Toast.makeText(getApplicationContext(), "Facebook Error: " + error.getMessage(),
                    Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onCancel() {
            Toast toast = Toast.makeText(getApplicationContext(), "Update status cancelled",
                    Toast.LENGTH_SHORT);
            toast.show();
        }
    }

Hackbook App Requests

import android.os.Bundle;
import android.widget.Toast;

Bundle params = new Bundle();
params.putString("message", getString(R.string.request_message));
Utility.mFacebook.dialog(Hackbook.this, "apprequests", params, new AppRequestsListener());

public class AppRequestsListener extends BaseDialogListener {

        @Override

        public void onComplete(Bundle values) {

            Toast toast = Toast.makeText(getApplicationContext(), "App request sent",

                    Toast.LENGTH_SHORT);

            toast.show();

        }

        @Override

        public void onFacebookError(FacebookError error) {

            Toast.makeText(getApplicationContext(), "Facebook Error: " + error.getMessage(),

                    Toast.LENGTH_SHORT).show();

        }

        @Override

        public void onCancel() {

            Toast toast = Toast.makeText(getApplicationContext(), "App request cancelled",

                    Toast.LENGTH_SHORT);

            toast.show();

        }

    }