Stephens' C# Programming with Visual Studio® 2010 24-Hour Trainer

Programming Databases, Part 2

The simple programs described in the previous lesson are hardly commercial-caliber database

applications, but they do let you perform basic database operations with amazingly little code.

In this lesson, you learn how to add a few new features to the programs described in

Lesson 35. You learn how to add searching, filtering, and sorting to the programs to make

finding data easier.

SEARCHING

In a large database, it can be hard to locate a particular value. A program can make finding

records easier by using the

BindingContext’s Find method. This method takes as parameters

the name of a field and the value that it should find. It returns the index of the first record that

has the desired value.

For example, the following code searches the data in the

BindingSource named contacts-

BindingSource

for a record with FirstName value equal to Kim:

int recordNumber = this.contactsBindingSource.Find(“FirstName”, “Kim”);

Having found the index of the target record, you can then highlight it in some way for the user

to see. For example, recall that a

BindingSource’s CurrencyManager controls the current

position within the data. The following code makes the current record be the record found by

Find so any controls displaying the data will show this record:

this.contactsBindingSource.CurrencyManager.Position = recordNumber;

Find returns –1 if it cannot find the target string. Be ...