Hi, I am using metatrader,and developing my application, I want use OPFX API, historic data for graphic and real time data for market watch. I checked marketwatch component yet, but didnot see how to connect mt4 with marketwatch component low level apis ? so which way to use these apis in to my application ?

Do you want to use the MarketWatch component, or you want to use the trading and data functionality?

By default MarketWatch connects to any data source, so it can connect to MT4 too; if you want to use MT4 connection for automated trading look into creating a custom expert.

Hi,
I mean How Can I use data where received marketwatch components, I need just, these realtime data to use in my application, how can I take these datas via experts? to driect my app.

The code is very simple, look at the MarketWatchComponent and MarketWatchControl classes. The MarketWatchComponent stores the data and the MarketWatchControl visualizes it. Look at the component_QuotesUpdateEvent() inside MarketWatchControl class. You can put some of your custom code there (for ex. send to your application), and it will get executed every time a quote comes in. This is the easiest approach, but I suggest you look over those 2 classes and see if you can understand how they work, so you can do whatever you wish.

It is best if you "plugin" your code inside the MarketWatch control and component (or make a copy, if you do not wish to modify the original classes), since it already does allot of things, and doing those from scratch takes effort.