How to Provide Search Feature in DataGridView: Windows Forms

We have successfully bind our datagridview with a list of items discussed in earlier post. What if there are many records in our list and datagridview is looking full of records. In this case, user can’t even search any single record, if he/she find, it will be a time consuming process.

So we (The Programmer) have to provide a search feature, through which the user can find some records according to the desired condition. A textbox have its TextChanged event that is triggered when the text value of the textbox is changed. So our task is to write some code in this event, so that when user change the text, the datagridview vary according to the code.

Create a list and bind a datagridview with that list. Add a textbox in the form and generate its TextChanged event and write the following code as it is.

private void searchTextBox_TextChanged(object sender, EventArgs e)
{
if (searchTextBox.Text != string.Empty)
{
var searchResult = stuList.Where(a => a.Name.StartsWith(searchTextBox.Text));
dataGridView1.DataSource = searchResult.ToList();
}
else
dataGridView1.DataSource = stuList;
}

The code will search all the records that’s name will be starts with the given text in the searchTextBox. The following image shows the result after write the character “B” in the textbox. Only a single record will be shown because there is only a single record in the list.

Now if we don’t know the starting characters of the name then there is another function i.e. Contains() that can be used to search all the records that contains the text. Just replace the first line with the below line.

var searchResult = stuList.Where(a => a.Name.Contains(searchTextBox.Text));

Run the project and write the character “o” in the textbox and it will show the result in datagridview as shown:

The datagridview binding will vary with the text changed in the textbox, and if the textbox left empty then it will show all the records of the list.

Exploring the visual studio 2012 IDE : Part-2

Toolbox

The Toolbox contains a number of tabs and each tab contains a list of controls and components that can be dragged onto your Web form. The Toolbox is docked on the left-side of the IDE; however, if it is not visible, you can access the Toolbox from the View menu or press the CTRL+ALT+ X keys together to open it.

There are different sets of controls available, depending on the type of the designer that is active in the editor. If you are designing a Web Form, you will get a specific set of tools that work with Web controls. If you are designing Windows Form, you will get a specific set of tools in the visual studio IDE for windows controls. If you are designing an XML document, there will be some other controls available within the TollBox. You can also add other customized tabs to the Toolbox wherein you can place your favorite controls and components or add your own customized controls.

The Code Editor Window

The Code Editor window allows you to write and edit code. You can press the F7 key to switch from the web Forms Designer to Code Editor. Alternatively, you can switch to code Editor by selecting View-->Code. You can use the same editor to create different types of files, such as text files and XML documents. In such a case, this window is called Text Editor

Using the Code Editor window, you can set breakpoints for debugging the application, and collapse sections of code to increase readability. The code Editor window also contain the intellisense feature that makes programming easier.

Intellisense

intelliSense is an extremely useful feature in visual studio. This, as you type the code, provides a list of options for making language references easily accessible and helps you in finding the information you need.
Intellisense is very helpful, as it automatically completes typing for you. For example, when you type TextBox1 and then a period operator(.), Intellisense displays a list of options. Now you can directly enter the member function or variable by using the list of options.

The Intellisense technology makes writting of code easier and less prone to errors. It provides quick access to valid member functions or variables, including global variables through the members list. You can select these member functions and variables from the list and use it in your code. Intellisense is also used to view code comments, function declarations, and variable type information. By default, Intellisense works automatically. However, if you prefer to invoke Intellisense explicitly with a menu command or a key combination, disable it by turning it off selecting the Tools-->Options-->Text Editor-->All Languages-->General Option and then deselect the Auto members and Parameter information check boxes. Now, if you want to incorporate the intellisense functionality in the code, You will have to use the Intellisense menu item in the Edit menu.
Visual Studio provides a new features wherein you can make the Intellisense drop-down list transparent. To do so, press the CTRL key while the Intellisense drop-down list is open and you can see the Intellisense drop-down list in a transparent mode that enable you to look at the code without closing the Intellisense.

Various options available in Intellisense are as follows:

List Members- Displays a list of valid member variables or functions for the selected class or structure selecting from the list inserts the member into your code.
Quick Info--Displays the complete declaration for any identifier in your code. Intellisense usually runs as soon as you type the period after a class instance. However, there are occasions where you need to force Intellisense to appear. For example, suppose you misspell a method name, then the Intellisense will not appear because of the wrong function name. You can bring Intellisense appear by pressing CTRL+j keys together. This allows you to select the appropriate method through Intellisense and replace the misspelled method name with the selected one.
Parameter info--Displays the complete declaration, including a parameter list for the method, such as number, name and types of parameters required by a method. You can also force Intellisense for parameter information for methods. For that, type an open parenthesis after the name of the function. Intellisense displays a complete list of the declaration function in a pop-up window and the first parameter appear in bold. By the time you specify the first parameter , the next parameter in the list is highlighted in bold. To close the list, you can press ESC at any time or keep typing the parameters till you complete the method. If you close the closing parenthesis, the parameter list also closes automatically.

Complete Word -- Shows the rest of a variable or function name once you have entered sufficient initial characters to differentiate the term. When you start typing a word and typed sufficient initial character so that it uniquely identifiers a given word in your current file, try pressing the CTRL+SPACEBAR+ keys together. The usual Intellisense drop-down list will be displayed by the specified starting characters. Simply select the appropriate word to complete the word quickly. If the series of starting letters uniquely identifies a single word in the Intellisense list, then the complete word will be inserted automatically. For example, to make the fontFamily property appear quickly on the code Editor, type font on the Code Editor. An Intellisense drop-Down list appear with options starting from Font, such as font, fontConverter, FontFamily, FontHeight. The moment you enter F, the selected item becomes FontFamily and you can press the Enter key to make the FontFamily word appear quickly on the code Editor.

Atomic,List and Union Data Types in XML Schemas

Atomic Data Types

Atomic data types cannot be broken down into smaller units. These data types can be primitive or derived. For example, the string primitive data type cannot be broken down further into smaller units, such as a characters.

List Data Types 

List data types are derived data types that contain a set of values of atomic data types elements referring to a list data type can contain a value only from that defined set. For example, you can create a list data type called pointlist, which is derived from the data type decimal and contains the following values .5, 2.5, and .75. Any element that is associated with the pointlist data type can contain only .5, 2.5, or .75 as its value.

Union Data Types

Union data types are derived from the atomic list data types. For example, if zip name is an atomic data type that can n create a data type called zips that can contain a combination of both these data types. Now, if you create an element called ZIPCODE of type zips, then ZIPCODE  element can contain the values shown in the following code snippet:

<ZIPCODE>NY</ZIPCODE>
<ZIPCODE>90547  96098 90contain only string values and zipnum is a list data type that can contain a list of zip code numbers, then you ca878 </ZIPCODE>
<ZIPCODE>CA </ZIPCODE>

Derived Data Types in XML Schemas

Introduction

Derived data types are defined by using other data types called base types. Base data types can either be primitive or derived data types. Derived data types can be built-in or user-defined. For example, integer is a built-in data type that is derived from the decimal data type.

Derived Data Types	Base Data Type	Description
Integer	Decimal	Represents a sequence of decimal digits with an optional leading sign (+ or -)
long	Integer	Represents a value within the range -9223372036854775808 to 9223372036854775807
nonNegativeInteger	Integer	Represents an integer that is greater than or equal to zero
Positive Integer	nonNegativeInteger	Represents an integer greater than zero
int	Long	Represents an integer within the range -2147483648 to 2147483747
time	recurringDuration	Represents an instance of time that recurs every day.
date	timeDuration	Represents a time period that starts at the midnight of a particular day and ends at the next midnight.

Primitive Data Type in XML Schemas

Introduction

Primitive data type are the fundamental data types of XSD. These data types are the basis for defining other data types in XSD. Primitive data types dot not contain elements or attributes. They contain only values.

Some of the primitive data types supported by XSD are listed in the following table.

Primitive Data Type	Description
String	Represents a collection of characters.
Decimal	Represents decimal numbers. This can be used to accurately define a value.
Float	Represents single-precision 32-bit floating-point numbers
Boolean	Represents Boolean values. This data type can have a value of true or false
timeDruration	Represents certain duration of time.
RecurringDuration	Represents a time duration that recurs after a specific interval.

Advantages of XML Schemas Created Using XSD

An XML schema defines the list of elements and attributes that can be used in an XML document. In addition to the list of elements, an XML schema specifies the order in which these elements appear in the XML document, and their data types.
Microsoft has developed the XML Schema Definition(XSD) language to define the schema of an XML document. XML schema s  have now become a w3c recommendation for creating valid XML documents.

Advantages of XML Schema s Created Using XSD
Some of the advantages of creating an XML schema by using XSD are:

• XSD provides control over the type of data that can be assigned to elements and attributes.
• XSD enables you to create your own data types. This feature enhances the flexibility of defining the structure of the XML document.
• XSD enables you to specify restriction on data. For example, you can ensure that the content of an element is a positive integer value.
• The syntax for defining an XSD is the same as the syntax used for xml documents. Therefore, it is easier to learn the syntax of an XSD.
• XML schema content models can be used to validate mixed content.
• XML schema is extensible. This enables you to reuse parts of a schema in another schema and derive custom data types from existing data types.
• XML schema is self documenting. Using the annotation element you can specify the intended purpose and attribute of a schema. This enables effective use of the schema by other.

Creating an XML Document

Problem Statement

CyberShoppe, Inc. sells toys and books in the United States. It has three branches in different parts of the country. Currently, the three branches maintain data on their local computer systems. The IT manager at CyberShoppe has identified that a centralized data repository on the products sold through its e-commerce site is required. The data from all branches must be collated and housed in a centralized location. This data must be made available to the accounts and sales sections at the individual branches, regardless of the hardware and software platforms being used at the branches. In addition, the sales personnel require access to the data using palmtops and cellular phones.
The product details of CyberShoppe consists of the product name, a brief description, the price, and the available quantity on hand. A product ID uniquely identified each product.

Solution
To solve the preceding problem, you need to perform the following tasks:

1. Identify the method to store data in a device-independent format.
2. Identify the structure of the document in which data is to be stored.
3. Create an XML document to store the data.
4. View the XML document in a browser.

Task 1: Identifying the method to store the Data in a Device-Independent Format

In the given problem statement, device ranging from mainframe computers to mobile phones must be able to access information from the data store. For example, the employee of the sales department may need to access product costs using an IBM PC. XML enables different types of devices to access information. Therefore, XML can be used to create the data store in the given scenario.

Task 2 : Identifying the Structure of the Document in Which Data is to be stored.

In the given scenario, PRODUCTDATA has been Identified as the root element. It has one child element, PRODUCT. The PRODUCT element can occur one or more times in the XML document. It acts as the container element for the PRODUCTNAME , DESCRIPTION, PRICE, AND QUANTITY elements. PRODUCTNAME has one attribute called PRODID, which is used to uniquely identify each product. The following figure illustrate the structure of the elements used in the XML document to store the product data.

Structure of the XML Document to Store Product Data

Task 3: Creating an XML Document to Store Data

To create an XML file that contains information about the products sold by CyberShoppe, type the following code in Notepad, and save the file as cyber_products.xml:

<?xml version="1.0" encoding="UTF-8" ?>
<!-- PRODUCTDATA is the root element -->
<PRODUCTDATA>
<PRODUCT PRODID="P001">
<PRODUCTNAME>Barbie Doll</PRODUCTNAME>
<DESCRIPTION>This is a toy for children in the age group of 5-10 years </DESCRIPTION>
<PRICE>12</QUANTITY>
</PRODUCT>
</PRODUCTDATA>

Task 4: Viewing the XML Document in a Browser

To View the XML document in the browser, open the cyber_products.xml file in Internet Explorer . IE provides a default tree view layout for an XML document. You can expand and collapse the tree.

The tree-view structure of the cyber_products.xml document is shown in the following figure