XML (Extensible Markup Language Scalable Language) In recent years, information magazines are available in recent years, the website is the most eye-catching word. The big and small information products are struggling to have a relationship with it, and they can't catch this quick train. The Borland Series Development Platform with a good reputation is no exception. It is integrated with XML component packages from version 6.0 because it uses the MSXmldom parser, which is more specified, Chinese. Compatibility is better (element name, attribute name supporting Chinese), is very popular among developers. To help beginners quickly master XML programming in Delphi, the author is close to this article for communication.
The author explains the steps of XML programming through an example of reading and writing XML files, and only the reader has nodes, elements, and attributes basic concepts. The XML file structure of the author to read is named INPUT.XML as shown below.
Age> 16
The first line of the input.xml file is the version of the XML. The property eNCoding declares what character set is built, default in Unicode encoding (UTF-8 or UTF-16), here is in Chinese GB2312. The second line "
TSTUDENT = Class {Student}
SEX: String; // Student Gender
Name: String; // Student Name
Age: integer; // Student age
Phone: String; // Phone number
END;
To read and write, we need to place two TXMLDocument controls. In the Internet tab of the Delphi VCL panel, the control of the XML word is that, of course, this control can also be created, but you need to include the necessary files, here is simplicity, We are placed directly on the form, named Inxmldoc and Outxmldoc, inxmldoc, used to transfer the input.xml file, OutxMLDoC is used to temporarily output to Output.xml documents.
Put your button on the form and we put the test code directly on the button. First define several variables to save temporary information, as shown below:
Root: ixmlnode; // Pointing XML root node
Parent_node: ixmlnode; // Point to the student node
Child_Node: ixmlnode; // Point to the child's sub-node
Student: TSTUDENT; / / Save a single student information
List: tlist; // 存 学生 list
I: integer; // cycle variable
Let's first read the XML file, the code is as follows:
List: = tlist.create; // Initialize list inxmldoc.loadFromfile ('INPUT.XML'); // Turn into input.xml file
Root: = inxmldoc.documentelement; // Take the root node of the XML file, ie "" Student Relief> "
Parent_node: = root.childNodes.first; // Points Parent_Node points to student nodes
While (PARENT_NODE <> nil) do // Take multiple students in loop, add several student information testing
Begin
IF (PARENT_NODE.NODENAME = 'Student') THEN / / Judgment is the node for students
Begin
Student: = TSTUDENT.CREATE; // Newly built a student structure information
Student.sex: = parent_node.attributes ['Gender']; // Take students' gender properties
Child_node: = parent_node.childnodes.first;
// Make Child_Node points to the first sub-node information of the student
While (child_node <> nil) do // Take each child of students
Begin
IF (child_node.nodeename = 'Name ") THEN / / Judgment is the name node
Student.name: = child_node.text // Take the value of the name node, taken in the Name field
Else if (child_node.nodeename = 'age') THEN / / The four lines of this line are similar to the first two lines
Student.age: = start_node.text)
Else IF (child_node.nodeename = ') THEN
Student.Phone: = child_node.text;
Child_Node: = child_node.nextsibling; // Sequentially remove a student's sub-node information
END;
List.add (student); // Add a student information to the list
END;
Parent_node: = parent_node.nextsibling; // Sequential to remove a student information
END;
Here, all student information has been stored in the list list, and the reader can track the code test.
Below we save the temporary student information in the list to the Output.xml file, the code is as follows:
Outxmldoc.active: = true; // Activate Outxmldoc, automatically initialize empty XML document
Outxmldoc.Encoding: = 'GB2312'; // Setting the character set
Root: = Outxmldoc.addchild ('Student Relief'); // Building a node
For i: = 0 to list.count - 1 do // Take each student information
Begin
Student: = list.Items [i]; // Sequential to take a student information
IF (student <> nil) THEN
Begin
Parent_node: = root.addchild ('student'); // Add a student node after root node
Parent_node.attributes ['Gender']: = student.sex; // Set Gender Properties for Students Node
Child_Node: = parent_node.addchild ('Name'); // Add a name NODE.TEXT: = student.name; // Set the text value of the name
Child_Node: = parent_node.addchild ('age'); // The four lines of this line look similar to the first two lines
Child_Node.Text: = INTOSTR (student.age);
Child_Node: = Parent_Node.Addchild ('Phone');
Child_node.text: = student.Phone;
END;
END;
Outxmldoc.savetofile ('output.xml'); // stores an organization's XML document in an Output.xml file
Outxmldoc.active: = false; // Passivation (close) Outxmldoc
List.free; // Last release of the preservation of temporary student information
Ok, see if INPUT.XML and OUTPUT.XML are the same. Is it very simple? In fact, there is also the same components in C Builder, just convert the Pascal syntax into a C syntax, the above code is completely used.
