ASP.NET PDF Viewer using C#, VB/NET

Users are free to modify URLs you can just type them into the address bar so a malicious user might decide to modify that part of the URL If the code just took the string from the URL and concatenated it directly into the SQL, we would effectively be giving anyone with an Internet connection the ability to run arbitrary SQL commands on our database SQL queries can contain multiple commands, so users would be able to add extra commands to run after the SELECT Parameters are one way to avoid this, because the value of a parameter will not be treated as SQL So it s a good idea to get in the habit of using parameters whenever some part of the query needs to change at runtime.

free barcode generator excel 2013, excel barcode add-in from tbarcode office, how to activate barcode in excel 2010, excel 2003 barcode add in, excel 2013 barcode add in, barcode font excel free download, install barcode font in excel 2010, barcode add in excel free, barcode excel 2010 freeware, excel 2003 barcode add in,

The API we used here directly reflects the steps needed to communicate with a database, so we have to write a lot of code to bridge between the queries, parameters, and columns of the database world and the world of C# Just as a sneak preview, Example 14-2 shows the equivalent code using the Entity Framework Notice that instead of having to build a parameter object for a parameterized query, we ve just been able to use a LINQ where clause and the C# == comparison syntax (The Entity Framework performs a parameterized query under the covers, so this is safe from SQL injection attacks) Also notice that all the database columns are available as object properties, so we don t have to call GetString or similar helpers to retrieve column values..

An aspect that is difficult to check with automated testing such as unit testing is user interaction. While most widgets have setters and getters that can be tested, to test user interaction you must be able to simulate mouse and keyboard activity. The QtTest module can help.

string state = "California"; using (var context = new AdventureWorksLT2008Entities()) { var addresses = from address in context.Addresses where address.StateProvince == state select address; foreach (var address in addresses) { Console.WriteLine(address.AddressLine1); Console.WriteLine(address.AddressLine2); Console.WriteLine(address.City); }

}

Example 14-1 has one obvious benefit in exchange for the complexity: we have complete control over the SQL query. You can t see the SQL in Example 14-2 because it gets generated for you. In general, the low-level ADO.NET API gives us more direct

access to database features for example, with SQL Server you can arrange to be notified when a query you executed earlier will now return different results due to changes in the database. (This can be useful in caching systems ASP.NET s cache can take advantage of this. It needs to be used with care, however, because it requires you to keep a database connection open at all times, which can cause severe scaling problems.) Another potential benefit is that Example 14-1 does not require the application to commit to the Entity Framework s way of doing things. Not all applications necessarily want to use databases in the way the Entity Framework chooses to. The use of this old-style part of ADO.NET usually comes down to a need for control over some specific aspects of data access, or occasionally because it offers performance benefits in certain specialized scenarios. But for the majority of developers, this style of data access will be unnecessarily low-level and verbose. These interfaces are not the only part of ADO.NET v1 it has another piece whose job is to manage data after the query that fetched it has completed.

To test a widget, you ll put the QSpinBox class to the test, focusing on the capability to change values up and down and that the minimum value and maximum value are respected. Because the value can be changed in three different ways, the test class shown in Listing 16-15 contains three test case slots: testKeys: Tests altering the value using keyboard interaction testClicks: Tests altering the value using mouse interaction testSetting: Tests altering the value using the setValue method There are no differences between a unit test class testing a widget and a nonwidget. Listing 16-15. A class for testing the QSpinBox class class SpinBoxTest : public QObject { Q_OBJECT private slots: void testKeys(); void testClicks(); void testSetting(); }; The first test case you ll consider is the testSetting slot, shown in Listing 16-16. In this test case, it doesn t matter that the class being tested is a widget; you ll just test the value property. First a QSpinBox object is created; subsequently its range is set to 1 10. The tests then try setting a valid value, setting a too-small value and finally setting a toolarge value. The valid value is expected to stick, while the other two are expected to be kept within the specified range. Listing 16-16. Testing the value property using a programmatic interface void SpinBoxTest::testSetting() { QSpinBox spinBox; spinBox.setRange( 1, 10 ); spinBox.setValue( 5 ); QCOMPARE( spinBox.value(), 5 );

The code behind this page should look something like this: <%@ Page Language="C#" AutoEventWireup="true" CodeFile="ChangeVisibility.aspx.cs" Inherits="ChangeVisibility" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server"> <title>Untitled Page</title> </head> <body> <form id="form1" runat="server"> <div> <atlas:ScriptManager ID="ScriptManager1" runat="server"> </atlas:ScriptManager> </div> <div id="panel" style="width: 100px; height: 100px"> This is the text that is going to be made invisible</div> <input id="Button1" type="button" value="button" /> </form> </body> </html> The next task is to add the Atlas code that allows you to change the visibility of the panel whenever the user clicks the button. You will do this using some JavaScript. Add the following JavaScript to the bottom of the page, beneath the closing </form> element and above the </body> element: