How to implement dual Buffering
The implementation program is provided first, and then explained again, also in ondraw (CDC * PDC:
CDC memdc; // define a display device objectCbitmap membitmap; // defines a bitmap object.
// Create a memory display device compatible with Screen DisplayMemdc. createcompatibledc (null );// No drawing yet, because there is no place to draw ^_^// A bitmap compatible with scre
Introduction
Removing flicker from an MFC application is well-covered territory. you can find the topic addressed in books, and on-line. however, the techniques presented are somewhat complicated and are usually difficult to add to an existing application. one often-presented technique is called double buffering. double Buffering allows the new screen to be drawn in off-screen memory, and then the completed screen is bit-blited back onto the physical screen.
This article presents a class calledC
, and then find the "wm_timer" message, which is the timer message, click "
Well, the preparation for the message handler is done, and we're going to start building the class. Specification code, easy to maintain, easy to read, the teacher said you understand:))
Here we build two simple classes on the line, one is the clock class Cclock, one is the needle class (hour, minute, seconds) Cneedle, in the solution view we right-click "header File", add-a class to create these two classes
Once you'v
Truncate table t_test: Message 4711, level 16, status 1, 1st rows
The table 't_ test' cannot be truncated because it has been published for replication. Error table forwarding from http://technet.microsoft.com/zh-cn/library/cc645613 (V = SQL .105). aspx
4711
16
No
The table '%. * ls' cannot be truncated because the table is published for replication or Change Data Capture is enabled.
I checked it for a long time. There is one of the following solutions, but i
maintenance of the log table needs to be done by the business System program in code.6. System Log Analysis methodThis method can judge the changing data by analyzing the log of the database itself. Relational plow the database system will store all DML operations in the log file for the database backup and restore functions. ETL Halo extraction process through the analysis of the database log, extract the relevant source table after a certain time after the DML operation information, you can k
transmitted from the dialog box, but the customer zone coordinates were used when the canvas was created for drawing. Then the two coordinates are unified, and the problem of blinking is solved.
In fact, I have a better understanding of Dual-cache. Next I will post the code of Dual-Cache implementation in my program:Cpaintdc DC (this); // device context for painting
On the Internet, we can see that everyone else is using the cmemdc class. As a result, I want to study the content in this area.
onpreparedc (CDC * PDC, cprintinfo * pinfo = NULL) to cchildview );
Void onpreparedc (CDC * PDC, cprintinfo * pinfo ){Crect rect;
// Set the loing mode to lometric (0.1mm) and the upper right to the growth direction.PDC-> setmapmode (mm_lometric );
// Set the coordinate origin to the center of the customer ZoneGetclientrect (rect );PDC-> setviewportorg (rect. Width ()/2, rect. Height ()/2 );}Responds to th
program. The dialog box can be changed to an elliptical form:
BOOL CTestDlg::OnInitDialog(){CDialog::OnInitDialog();...CRgn rgn;rgn. CreateEllipticRgn(0,0,200,100);SetWindowRgn(rgn,TRUE);}
Figure 1 elliptical form
IV,Create a "region" using the plotting Path Method"
The process for creating a "region" using this method is as follows:The first step is to draw the shape of the form to be created.Some member functions in the CDC class are used in this s
business system and update the maintenance Log table contents when the business data changes, asWhen ETL is loaded, the data is determined by reading the log table data and how to load it.Advantages: No need to modify the business system table structure, the source data extraction clear, faster. Can increase the number of dataLoad.Disadvantages: Log form maintenance needs to be completed by the business system, the business system business operating procedures to be modified, record dayLog info
3. Create a drawing tool and select INTO DCWith the canvas, we have to have a paintbrush brush to draw. With GDI objects such as Hpen, Hbrush, and so on in Windows, MFC encapsulates GDI objects nicely, providing classes that encapsulate GDI objects, such as CPen, CBrush, CFont, CBitmap, and CPalette, These classes are derived classes of the GDI object class CGdiObject.Usually first create a brush (brush), and then call the CDC::SelectObject function t
, and current font.Pen and brush are independent GDI objects. You can use the SelectObject () function of the CDC member function to select DC. Objects in the same operation method include font, bitmap, palette, and region ).About SelectObject (): After a GDI object is created, SelectObject () receives the pointer of this object. The returned value is the same type of object pointer of the DC (usually used to restore the DC ).Windows also pre-defines
IBM provides comprehensive and industry-leading data warehousing and business analysis solutions, including information integration tools InformationServer, real-time and incremental data replication tools InfoSphereCDC, and data warehousing solutions InfosphereWarehouse; business analysis tools CognosBI and a series of business analysis applications.
IBM provides comprehensive and industry-leading data warehousing and business analysis solutions, including Information Server, InfoSphere
using the code and constraint files above. Then click on synthesize-xst to synthesize the whole project again.2. Select the top-level module name Led_top, then right-click the new source option and select the second Chipscope Definition and Connection file option in the Popup New Source wizard interface. and take the name chipscope_led (name can be taken casually), and then click Next3. Click Next to click Finish in the popup dialog box.4, Finish Click after completion, and so on for a period o
I. paletteOn a computer that uses a 256-color graphics card, each program allows a total of 256 colors. However, apart from the 20 static colors reserved by the operating system, the other 236 colors allow each application to decide on its own. So we have a palette. Applications running on such computers must select the main colors they need into the color palette of the video card for better display. To use the color palette, we first need to know the type of the computer graphics card to deter
of the MFC Dialog Box program. The dialog box can be changed to an elliptical form:
Bool ctestdlg: oninitdialog (){Cdialog: oninitdialog ();...Crgn RGN;RGN. createellipticrgn (0, 0, 200,100 );Setjavaswrgn (RGN, true );}
Figure 1 elliptical form
Iv. Create a "region" using the plotting Path Method"
The process for creating a "region" using this method is as follows:
The first step is to draw the shape of the form to be created. Some member functions in the
an oval form:BOOL Ctestdlg::oninitdialog () { cdialog::oninitdialog (); ... CRGN Rgn; Rgn. CreateEllipticRgn (0,0,max,+); SetWindowRgn (rgn,true);}Figure One oval formFour, the drawing path method creates "region"The process for creating a "region" using this method is as follows:The first step is to draw the form shape you want to create.Some of the member functions in the CDC class are used in this step as follows:BOOL
increase load. Disadvantage: Log table maintenance needs to be completed by the business system, the business system business operation procedures need to be modified to log information. Log table maintenance is more troublesome, the original system has a greater impact. Heavy workload, large changes, there is a certain risk.(f) Oracle change data Capture (CDC mode)The data is judged by analyzing the log of the database itself. Oracle's change data C
ReferenceArticle: Bai Qiao Original: Beautification interface of VC
Before each control is drawn, a wm_ctlcolor notification message is sent to its parent window. In the message processing function, you can set the foreground color, background color, and font of the control to display the text. The message processing function also requires that a paint brush handle be returned to erase the customer zone before the control is drawn.
The message processing function of wm_ctlcolor ing is afx_ms
LOG_REUSE_WAIT_DESC for replication?The suspect was transferred to the CDC.SELECTis_cdc_enabled, Case whenIs_cdc_enabled= 0 Then 'CDC feature disabled' ELSE 'CDC feature enabled'ENDDescription fromSYS. DATABASESWHERENAME= 'XXXX'The library does open CDC and continues to check the health status of the
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