data matrix generator c# open source MANAGED PROVIDERS OF DATA ACCESS in visual C#

Embed data matrix barcodes in visual C# MANAGED PROVIDERS OF DATA ACCESS

Sub RestrictPTDrag() Dim pt As PivotTable Dim pf As PivotField On Error Resume Next Set pt = ActiveSheet.PivotTables(1) For Each pf In pt.PivotFields With pf .DragToPage = False .DragToRow = False .DragToColumn = False .DragToData = False .DragToHide = False End With Next pf Set pt = Nothing End Sub To run the code, use a method described in Section 11.1. The code refers to ActiveSheet, so you can run the code on any sheet that contains a pivot table.

At this point, you ve seen how to call native functions in two ways from managed code using P/Invoke and by linking with the appropriate binary and including the appropriate header. You ve gotten a taste of the conversions that are used and some of the concerns when calling native code, such as pinning movable data.

When we call the PerformCalculation method, we have to be careful to catch and handle the exception that will be thrown if the parameter is out of range. As a convenience, we can use the TryXXX pattern to create an additional method that acts as a wrapper around PerformCalculation and takes care of the exception for us, using the method result to tell us whether the calculation succeeded and an output parameter to give us the result. Listing 9-13 demonstrates how this can be done. Listing 9-13. Using an Output Parameters as Part of the TryXXX Pattern class Calculator { public int PerformCalculation(int x, int y) { if (x > 10 || y > 10) { throw new ArgumentOutOfRangeException(); } else { return x * 10; } } public bool TryPerformCalculation(int x, int y, out int result) { try { result = PerformCalculation(x, y); return true; } catch (ArgumentOutOfRangeException) { result = -1; return false; } } } The naming convention for this kind of method is to prepend the word Try to the name of the method that it mediates access to. In this example, since the original method is called PerformCalculation, the additional method is called TryPerformCalculation. You can see that the TryPerformCalculation method has an additional parameter that has been modified with the out keyword, indicating that this is an output parameter. The method body uses a try statement to call the PerformCalculation method, assigns the result to the output parameter, and returns true. If the PerformCalculation method throws an exception, the catch clause of the try statement sets the value of the output parameter to -1 and return false. (Exceptions, try statements, and catch clauses are all covered in 14.) So, if the TryPerformCalculation method returns true, we know that the underlying calculation was performed without a problem and that the output parameter contains the result. If the TryPerformCalculation method returns false, we know that the calculation didn t succeed, and we should ignore the value of the output parameter. Listing 9-14 shows the TryPerformCalculation method in use. Listing 9-14. Calling a TryXXX Method class Listing 14 { static void Main(string[] args) { // create a new instance of Calculator

The error icons next to the two date fields, along with the tooltip text, come from the ErrorProvider control. Of course, it gets its information from the Project object itself through the IDataErrorInfo interface implemented by BusinessBase in 3. The ErrorProvider control was simply dragged from the toolbox onto the designer, and its DataSource property set to the projectBindingSource control, as shown in Figure 9-22.

<dropCueTemplate> <template layoutElement="dropCueTemplate" /> </dropCueTemplate> </dragDropList> </behaviors> </control> <control id="PHItem"> <behaviors> <draggableListItem handle="PHDiv" /> </behaviors> </control> <control id="PHGraph"> <behaviors> <draggableListItem handle="PHGraphDiv" /> </behaviors> </control> <control id="PHAnalytic"> <behaviors> <draggableListItem handle="PHAnalyticDiv" /> </behaviors> </control> </components> </page> </script> When using Atlas Script, you define controls, behaviors, and actions using an XML document. You can see a lot more detail about it in 5. This script defines four Atlas controls. Each control is associated with an underlying HTML element. The first MasterList is an HTML list element. Each of the three panes is defined within a list element (<li> tag). This allows the panes to be dragged and dropped and locked into portions of the page. It s a three-item HTML list, and when you drag and drop the items, you simply rearrange how the elements are represented on the list. You associate the <dragdropList> behavior with this element to turn it into a list where the items can be rearranged using drag and drop. The Atlas Script that provides this is as follows: <dragDropList dataType="HTML" acceptedDataTypes="'HTML'" dragMode="Move"> <dropCueTemplate> <template layoutElement="dropCueTemplate" /> </dropCueTemplate> </dragDropList>

Let s look first at the AddBusinessRules() implementation: Protected Overrides Sub AddBusinessRules() ValidationRules.AddRule( _ AddressOf Validation.CommonRules.StringRequired, "Name") ValidationRules.AddRule( _ AddressOf Validation.CommonRules.StringMaxLength, _ New Validation.CommonRules.MaxLengthRuleArgs("Name", 50)) ValidationRules.AddRule(AddressOf StartDateGTEndDate, "Started") ValidationRules.AddRule(AddressOf StartDateGTEndDate, "Ended") End Sub This method is automatically invoked by the CSLA .NET framework any time validation rules need to be associated with the object s properties. The method should only contain a series of ValidationRules.AddRule() method calls as shown here. Each call to AddRule() associates a validation rule with a property. In the simple case, this means associating a rule method like StringRequired to a property like Name: ValidationRules.AddRule( _ AddressOf Validation.CommonRules.StringRequired, "Name") With this done, any time PropertyHasChanged() is called by the Name property, or ValidationRules.CheckRules() is called anywhere in the object, the rule will be applied to the Name property by executing the StringRequired method. The implementation for this method was covered in 5.

While establishing Forms authentication under ASP .NET 1.1 was certainly not rocket science, you may agree that there is room for improvement. First and foremost, the Web-based UI that defines a typical logon.aspx page is more or less identical across web applications (add Labels, TextBoxes, Buttons, etc). As well, the validation code found within the code-behind files of an ASP.NET 1.1 logon.aspx page is also more or less identical (open a database connection, format the SQL, submit the SQL, and so forth). While you could encapsulate these details using a custom UserControl, this approach to UI reuse presents a new set of snags. ASP .NET 2.0 simplifies authentication/authorization tasks with the following new security-centric techniques: The Membership class The Role Manager class Authentication-centric ASP .NET Web Controls As an added bonus, ASP .NET 2.0 also offers a Web-based UI editor for web.config files. Not only does this help prevent the developer from indirectly introducing malformed XML, this Web-based editor also facilitates remote website administration. You ll come to know the ASP.NET Web Site Administration Tool at the conclusion of this chapter.