barcode reader integration with asp net CH A PT ER 7 PRO PERTY DE CLA RAT IO NS in .net C#

Creator pdf417 in .net C# CH A PT ER 7 PRO PERTY DE CLA RAT IO NS

// OK: return a nontemporary reference. R% R::GetTrackingRefMF() { return *this; } // Value type return value: OK V GetValue() { V v; v.a = 100; v.b = 54; // Value gets copied. return v; } // Return value with stack semantics. // Requires copy constructor R GetR() { R r; return r; // requires copy constructor }

The ApplyWriteRules() method is similar to ApplyReadRules() but takes a slightly different approach. In this case, users may be able to view the data, but they certainly can t be allowed to edit the data. If the control implements a ReadOnly property, then it can be set to False; otherwise, the control must be entirely disabled through the use of its Enabled property. As an optimization, if the control is a Label, the method will exit immediately. Because Label controls are so common and they are read-only by definition, it is worth this special check. The preference is to use the control s ReadOnly property if it is implemented by the control. Reflection is used to get a PropertyInfo object corresponding to the control s ReadOnly property. ' enable/disable writing of the value Dim propertyInfo As PropertyInfo = _ ctl.GetType().GetProperty("ReadOnly", _ BindingFlags.FlattenHierarchy Or _ BindingFlags.Instance Or _ BindingFlags.[Public]) If propertyInfo IsNot Nothing Then Dim couldWrite As Boolean = _ (Not CBool(propertyInfo.GetValue(ctl, New Object() {}))) propertyInfo.SetValue(ctl, Not canWrite, New Object() {}) If (Not couldWrite) AndAlso (canWrite) Then binding.ReadValue() End If End If If a ReadOnly property is found, then it is set to True or False depending on whether the user is allowed or denied write access to the business object property. propertyInfo.SetValue(ctl, Not canWrite, New Object() {}) First, though, the value of the control s ReadOnly property is retrieved. If it is False, that means that the user was already able to edit the control the user could write, so couldWrite is True. This is important, because if the user was unable to edit the control and now is able to edit the control, data binding needs to be told to reload the data from the data source into the control. If (Not couldWrite) AndAlso (canWrite) Then binding.ReadValue() End If Otherwise, it is possible for the user to be placed into an empty control even though there really is a value in the business object s property.

NOTE Compile time or static verification is available only in the Premium/Ultimate editions of Visual Studio. This is a real shame because it will probably prevent widespread adoption of this great technology rather than encouraging users to purchase a more expensive edition of Visual Studio (similar to MSTest & VS2005 ). Hopefully this is not permanent, and you will see static verification available in all future versions of Visual Studio.

2 l_start number := dbms_utility.get_cpu_time; 3 begin 4 for x in (select object_name from stage) 5 loop 6 insert into t (encrypted_name) 7 values ( encryption_wrapper.encrypt 8 (x.object_name, 9 "Secret Key Secret Key Secret Key")); 10 end loop; 11 dbms_output.put_line( (dbms_utility.get_cpu_time-l_start) || " hsecs" ); 12 end; 13 / 2502 hsecs PL/SQL procedure successfully completed. it takes 25.02 CPU seconds to generate and insert the data. Thus, it takes almost six times more CPU to perform the encryption as opposed to leaving the data unencrypted. Even if we bulk up the operation, using an INSERT AS SELECT statement, we ll see a large disparity: ops$tkyte%ORA11GR2> truncate table t; Table truncated. ops$tkyte%ORA11GR2> declare 2 l_start number := dbms_utility.get_cpu_time; 3 begin 4 insert into t (last_name) select object_name from stage; 5 dbms_output.put_line( (dbms_utility.get_cpu_time-l_start) || " hsecs" ); 6 end; 7 / 8 hsecs PL/SQL procedure successfully completed. ops$tkyte%ORA11GR2> truncate table t; Table truncated. ops$tkyte%ORA11GR2> declare 2 l_start number := dbms_utility.get_cpu_time; 3 begin 4 insert into t (encrypted_name) 5 select encryption_wrapper.encrypt 6 (object_name, 7 "Secret Key Secret Key Secret Key") 8 from stage; 9 dbms_output.put_line( (dbms_utility.get_cpu_time-l_start) || " hsecs" ); 10 end; 11 / 374 hsecs PL/SQL procedure successfully completed. Yes, 374 seconds versus 8 seconds is a more striking disparity, an almost 47 times increase in CPU utilization because of encryption when we performed the more efficient bulk operation. Clearly, this increased demand on CPU will have an impact on our modifications to the column. INSERTS, UPDATES, and MERGES will surely be affected, (but probably not DELETEs).

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