Shulou(Shulou.com)06/03 Report--

Let's briefly talk about my understanding of the principle of QTP recording and playback.

QTP records mouse and keyboard messages. QTP listens to the messages of the application during recording, and then puts the messages in the container, while other listeners take the messages from the container and call the corresponding API handler function. What QTP intercepts is the user's action on the application, that is, the message is recorded. QTP recording and playback is based on the message mechanism of the windows operating system. The QTP calls the API function based on the handle of the object and the content of the script during playback, while for the Bhand S application, it parses based on DOM (document object model) during playback

First of all, QTP identifies the object by recording the properties of the control (of course, which properties are used, QTP has a default or can be configured). Suppose QTP uses the "html tag" and "name" attributes to identify objects. How does QTP handle it? Please look at the following picture first:

Figure-QTP object recognition

When recording with QTP, QTP stores objects in the object library. Objects are stored in the object library as shown above. That is, QTP will default to give the recorded object a name (the name can be changed by itself, as long as it remains the same as the name when the object is used in the script), and then store the properties and property values that identify the object in the object library. We can first think of the property set that identifies the object as a property package, and then associate the property package that identifies the object with the defined object name. Also known as object mapping. Such an object is stored in the object library.

Let's go on to show how QTP calls this object. For example, enter "a user" in the user name input box with the pseudo code as follows:

WebEdit ("user name input box"). Set "a user"

Now analyze this statement:

First, QTP will look in the object name of the object library through the name "user name input box" and find the following object name:

In fact, the principle of QTP recording and playback, and later descriptive programming, virtual objects, is the same. They all record the main properties of the object, and then find the previously recorded object by comparison during playback.

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