Domain operations cannot be started at design time

abis 2010-07-09 10:35:28

做了一个自定义控件，下拉框，框中的项是从数据库中取得。控件做好后往主窗体上拖的时候，就出现了这个提示。请问如何解决？

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莫逍遥 2011-04-12

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[Quote=引用 1 楼 sunpire 的回复:]
在构造函数内不要出现调用业务逻辑（数据库）的代码，控件在设计器中被呈现时，会执行构造函数中的全部代码的，如果是模板化控件，则还会执行 OnApplyTemplate() 中的代码
[/Quote]

如果不在构造函数中做业务逻辑调用，那么在什么地方调用？

dale01 2010-10-17

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Very Good!

abis 2010-07-09

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已经解决，多谢。40分全拿去

Sunpire 2010-07-09

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在构造函数内不要出现调用业务逻辑（数据库）的代码，控件在设计器中被呈现时，会执行构造函数中的全部代码的，如果是模板化控件，则还会执行 OnApplyTemplate() 中的代码

---------------------------------------------------------------------- Remote Administrator 2.2 for Win9X/ME/NT4.0/2000/XP Software and all its components Copyright (C) 1999-2004 Dmitri Znosko. All rights reserved. Copyright (C) 1999-2004 Famatech International Corp. and its licensors. All rights reserved. Date: June 15th, 2004 ---------------------------------------------------------------------- You can find complete help in 'help.hlp' file ---------------------------------------------------------------------- Radmin ---------------------------------------------------------------------- Contents: * What is Radmin? - What makes it different from other systems? - Features * System requirements * Installation * Radmin Security * How to contact us ---------------------------------------------------------------------- What is Radmin? ---------------------------------------------------------------------- Radmin is a remote control program that lets you work on another computer remotely through your own. You see the remote computer's screen in a resizable window on your own monitor or as the full screen. Your mouse and keyboard control the remote computer so you can work on the remote computer just as if you were sitting right at it. The remote computer can be anywhere on the Internet or in your local network. You don't need a fast network connection. Even with a MODEM the screen update speed is an acceptable 5-10 screen updates per second. If the remote computer is on your LOCAL NETWORK the typical speed is from 100 to 500 screen updates per second. Often while working in Radmin's full-screen mode, you forget that you are working on a REMOTE computer! Radmin consists of two parts: * The server on the remote computer that sends the remote computer's screen display. * The client - also called the viewer - that shows the remote screen display on your own monitor. To get started you need to run Radmin server on the remote computer. Then run Radmin client on your own computer. The current version of Radmin requires a TCP/IP connection between both computers, so you'll need to set this up if they are not already connected. ---------------------------------------------------------------------- What makes it different from other systems? ---------------------------------------------------------------------- Radmin outperforms all other remote control software in speed, security and usability. Speed: Radmin is the fastest remote control software available. It is optimized for low-bandwidth connections such as modems. Connecting via modem, screen refreshment rate reaches 5-10 updates per second. If connected to a LAN you can work on remote computer with real-time speed, reaching over 100 screen updates per second. Security is a critical consideration when implementing the remote control software. To maintain the security of data and corporate network resources, Radmin supports the existing level of environment security and provide its own level as well. Radmin offers the highest levels of encryption available in its category. Usability: Radmin simple interface is devoid of useless 'value added features' that bloat software and make it hard to work with. Radmin is extremely easy to learn and use. ---------------------------------------------------------------------- Features ---------------------------------------------------------------------- Run as a Service Radmin server can work as a SERVICE under Win9x, ME, NT4.0, Win2000 and Winsows XP. This lets you log a user on or off remotely. NOTE: If Radmin server is started on Windows XP, the "Switch User" feature cannot be used. Multiple Connections Support Radmin server supports simultaneous multiple connections to the same remote screen. Full-Screen, Scaled and Windowed View Modes Full-screen mode shows the remote screen full-size on your own monitor Scaled mode lets you see the remote screen in a window on your monitor scaled to the remote screen's defined size. Video Hook Driver Technology is Used Radmin uses video hook kernel mode drivers under Windows NT to capture screen changes. This boosts the speed to hundreds of screen updates per second. File Transfer Current version lets you transfer files (less than 2Gb) between computers with Windows Explorer like interface. Remote Shutdown Now you don't have to connect in the Full Control mode. Telnet Server Radmin server provides Telnet access to remote computers (except on Win9x). Windows NT Security Support You can allow remote control, remote view, telnet and file transfer access to specific users or user groups from an NT domain. If a user logged into a WinNT domain connects to Radmin server, the user's current username/password are employed by Radmin viewer to authorize a connection to the Radmin server. Password Protection If Windows NT security support is switched off, access to a remote computer is controlled by a password. Radmin uses a challenge-response password authentication method based on 128 bit strong encryption. 128 Bit Strong Encryption of All Data Streams. In the version 2.2 encryption is always enabled, it causes just 5% performance loss. IP Filter Allows an access to the Radmin server only from specified IP addresses and subnets. Radmin Supports High-Resolution Modes Display resolutions up to 2048 X 2048 X 32 bit color are supported by Radmin. ---------------------------------------------------------------------- System requirements. ---------------------------------------------------------------------- No special requirements for hardware. Required software is Windows 95/ME/NT4.0/2000/XP with TCP/IP protocol installed. NOTE: If Radmin server is started on Windows XP, the "Switch User" feature cannot be used. NOTE: Radmin still operates successfully when the display, mouse and keyboard are disconnected from the remote computer, however some computers do not boot successfully without a keyboard plugged in. For All Operating Systems (Win9x/ME/NT/2000/XP): The computer must have TCP/IP installed, the most-used protocol for networking computers. Windows NT 4.0: Service pack 4 or higher is required. ---------------------------------------------------------------------- Installation. ---------------------------------------------------------------------- Two computers need to be connected by TPC/IP, either on a local network or the Internet. Radmin must be installed on each computer. Before Installation For All Users: Uninstall any earlier version of Radmin, before installing a newer version. Before Installation For All Users: * Uninstall any earlier version of Radmin, before installing a newer version. For Windows 2000/XP Users: * You need administrator rights to install Radmin Server as a service. For Windows NT 4.0 Users: * You need administrator rights to install Radmin Server as a service and install the driver. * Before installing Radmin's video hook driver be sure that any other Remote Control software that uses video hook driver technology has been removed. Running more than one video hook driver can lead to a system crash while booting. Sample applications that use a video hook driver: NetMeeting 3.0+, SMS, Timbuktu. If a problem occurs while booting with the Radmin driver, you can press the '1' (number one) key repeatedly during booting and the Radmin driver will not load. ---------------------------------------------------------------------- Limitations ---------------------------------------------------------------------- Radmin file transfer feature supports files up to 2Gb and folders with up to 20,000 files. Radmin may fail to operate correctly together with some applications causing high CPU usage, also with some specific antiviral software and firewalls. The product may be not compatible with some particular models of hardware, such as routers. ---------------------------------------------------------------------- Radmin Security ---------------------------------------------------------------------- A lot of attention was paid to security issues in the Radmin design from the outset. Here are some reasons that Radmin's operations are completely secure: * Radmin 2.2 supports Windows NT/2000/XP user level security. You can allow remote control to specific users or user groups. * If Windows NT security support is switched off, access to a remote computer is restricted by password. Remote Administrator uses a challenge-response password authentication method (MD5 and Twofish crypto algorithms are used). This method is similar to the authentication method used in Windows NT, but uses more powerful security keys. * Radmin works in encrypted mode, where all data, including screen images, mouse movements and keypresses are encrypted. 128 bit Twofish encryption is used. Twofish crypto is distinguished for its combination of speed, flexibility and conservative design. * Radmin server has a logging feature. All actions are written to the log file. Event Log support is also included. * Radmin server has an IP filter table that restricts remote access to IP addresses and networks you specify. * Radmin has a self testing code defence that protects the code from being altered. ---------------------------------------------------------------------- How to contact us ---------------------------------------------------------------------- Feel free to contact us. All registered users of Radmin can get full technical support. You can also clear up any questions about Radmin purchasing or offer suggestions. If you have something of interest about how you use Radmin, we'd be very happy to hear from you. If you simply want to express an opinion about our site, this is how to contact us. General - radmin@radmin.com Purchasing questions - sales@radmin.com Technical support - support@radmin.com Visit our site for the latest news, versions and updates www.radmin.com You can find complete help in 'help.hlp' file ---------------------------------------------------------------------- Software and all its components Copyright (C) 1999-2004 Dmitri Znosko. All rights reserved. Copyright (C) 1999-2004 Famatech International Corp. and its licensors. All rights reserved.

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