Search Functionality using LINQ The file, “Countries.txt” contains a list of countries from around the world. Place this file in your bin/debug directory.

Search Functionality using LINQ

The file, “Countries.txt” contains a list of countries from around the world. Place this file in your bin/debug directory.

In this assignment, you will create a Visual Basic program that reads the values from the Countries text file, displays those countries in a listbox, and allows the user to enter characters in a textbox to search for one or more countries in the listbox and display the results in another listbox. The number of countries returned from the search is displayed in a textbox below the results. The program also allows the user to sort the countries listbox in ascending or descending order. Finally, a clear button clears the results in the listbox, the search textbox, and the number of countries returned from the search textbox. A quit button is provided, which exits the application.

The figures below show the output of the Visual Basic program that performs the functionality described above.

Deliverables:

1. Write a Visual Basic program that displays the information below and performs the functionality described above.

2. Using the IO.File.ReadAllLines method, read the contents of the countries.txt file into an array.

3. When the form loads, display the contents of the array in the Coutnries listbox.

4. When the user enters something in the Search Country textbox and presses the “Go” button, the program should search the array upon which the countries listbox is displayed.Use a LINQ query to do this.Note that the user may type in a full country name as illustrated in Figure 1 below, or he may enter only part of the name (even one letter), and the listbox should be populated with all countries that start with the same letter(s) as those entered by the user.Figure 2 below illustrates the search for all countries that begin with the letter “D”.

• Be sure to make your search NON-case sensitive.That is, if the user enters “UnItEd sTateS” in the textbox, it should still retrieve the country “United States”. [Hint: If you convert the value that the user enters into uppercase and search for values that are converted to uppercase, this allows for a match to be found.]

• Using LINQ queries, write the code such that when the user clicks the Sort Ascending button, the countries displayed in the Countries listbox is sorted from A-Z.Conversely, when the user clicks the Sort Descending button, the listbox should be sorted from Z-A.Although this feature can be accomplished using the properties of the listbox, your code should be written using LINQ queries to perform these functions.

[Hint: Before you set the datasource property of your listbox to the results of your LINQ query, you must first remove the datasource linkage to the original array by setting .datasource = nothing.]

5. Using a certain property of listboxes, determine the number of search results displayed in the Results listbox and display that number in the textbox shown below the listbox.Note:Do NOT use a LINQ query for this task.

6. Use appropriate software development guidelines, such as clearing the results listbox before populating it with new data when the Go button is clicked and including a title on the form.

Countries List:

Afghanistan

Albania

Algeria

American Samoa

Andorra

Angola

Anguilla

Antarctica

Antigua and Barbuda

Argentina

Armenia

Aruba

Australia

Austria

Azerbaijan

Bahamas

Bahrain

Bangladesh

Barbados

Belarus

Belgium

Belize

Benin

Bermuda

Bhutan

Bolivia

Bosnia and Herzegovina

Botswana

Brazil

Brunei Darussalam

Bulgaria

Burkina Faso

Burundi

Cambodia

Cameroon

Canada

Cape Verde

Cayman Islands

Central African Republic

Chad

Chile

China

Christmas Island

Cocos (Keeling) Islands

Colombia

Comoros

Democratic Republic of the Congo (Kinshasa)

Congo, Republic of (Brazzaville)

Cook Islands

Costa Rica

Ivory Coast

Croatia

Cuba

Cyprus

Czech Republic

Denmark

Djibouti

Dominica

Dominican Republic

East Timor (Timor-Leste)

Ecuador

Egypt

El Salvador

Equatorial Guinea

Eritrea

Estonia

Ethiopia

Falkland Islands

Faroe Islands

Fiji

Finland

France

French Guiana

French Polynesia

French Southern Territories

Gabon

Gambia

Georgia

Germany

Ghana

Gibraltar

Great Britain

Greece

Greenland

Grenada

Guadeloupe

Guam

Guatemala

Guinea

Guinea-Bissau

Guyana

Haiti

Holy See

Honduras

Hong Kong

Hungary

Iceland

India

Indonesia

Iran (Islamic Republic of)

Iraq

Ireland

Israel

Italy

Jamaica

Japan

Jordan

Kazakhstan

Kenya

Kiribati

Korea, Democratic People's Rep. (North Korea)

Korea, Republic of (South Korea)

Kosovo

Kuwait

Kyrgyzstan

Lao, People's Democratic Republic

Latvia

Lebanon

Lesotho

Liberia

Libya

Liechtenstein

Lithuania

Luxembourg

Macau

Macedonia, Rep. of

Madagascar

Malawi

Malaysia

Maldives

Mali

Malta

Marshall Islands

Martinique

Mauritania

Mauritius

Mayotte

Mexico

Micronesia, Federal States of

Moldova, Republic of

Monaco

Mongolia

Montenegro

Montserrat

Morocco

Mozambique

Myanmar, Burma

Namibia

Nauru

Nepal

Netherlands

Netherlands Antilles

New Caledonia

New Zealand

Nicaragua

Niger

Nigeria

Niue

Northern Mariana Islands

Norway

Oman

Pakistan

Palau

Palestinian territories

Panama

Papua New Guinea

Paraguay

Peru

Philippines

Pitcairn Island

Poland

Portugal

Puerto Rico

Qatar

Reunion Island

Romania

Russian Federation

Rwanda

Saint Kitts and Nevis

Saint Lucia

Saint Vincent and the Grenadines

Samoa

San Marino

Sao Tome and Principe

Saudi Arabia

Senegal

Serbia

Seychelles

Sierra Leone

Singapore

Slovakia (Slovak Republic)

Slovenia

Solomon Islands

Somalia

South Africa

South Sudan

Spain

Sri Lanka

Sudan

Suriname

Swaziland

Sweden

Switzerland

Syria, Syrian Arab Republic

Taiwan (Republic of China)

Tajikistan

Tanzania officially the United Republic of Tanzania

Thailand

Tibet

Timor-Leste (East Timor)

Togo

Tokelau

Tonga

Trinidad and Tobago

Tunisia

Turkey

Turkmenistan

Turks and Caicos Islands

Tuvalu

Uganda

Ukraine

United Arab Emirates

United Kingdom

United States

Uruguay

Uzbekistan

Vanuatu

Vatican City State (Holy See)

Venezuela

Vietnam

Virgin Islands (British)

Virgin Islands (U.S.)

Wallis and Futuna Islands

Western Sahara

Yemen

Zambia

Zimbabwe