Turn to tree programming in Delphi

The tree structure usually uses the treeview control in delphi, and if you want to query data, it is usually used in conjunction with the database, the key point is the structure of the database, see the following information:

A less effort-effective approach is to use a third-party TreeView control with database support, such as dbtreeview.

Traverse, find all the subclasses and subclasses of the subclasses under the current node.

Assign the current state of a node to the state of all found nodes.

It shouldn't be difficult, right?

It seems that your thinking is really quite confusing, the problem description is quite confusing, and your requirements are not clearly described at all? When the parent node is clicked, what does it mean that the child node of the lower level is in the same state as the node is selected? Are all of them selected? Describe the problem clearly

You may consider using comboboxex components or other third-party controls.

The comboboxex component is similar to the combobox, but its item has an additional indent property, which is set to 0 1 2 3....You can show the hierarchy.

It is recommended to use the tadvtreecombobox control in the TMS control package, which is easy to use and functions similarly to TreeView + ComboBox:

First of all, determine the relationship between the three tables, if it is a simple no equality relationship, then only one SQL statement is needed:

select ,,from a,b,cwhere and

That's it.

The easy way to do this is to plug in.

asp file:

It can only be implemented in several widgets, click on the parent node, and in another widget, list all the child node information.

Each node may have subordinate nodes, which makes up the tree tnode = class

public

text: string;

children: tlist;

end;Traverse the display directly, and display controls such as tmemo to set up line wrapping.

Data from the data table is displayed in a tree view. It's a good way to do it. However, it takes a long time to load the view. It's annoying at the point.

Delphi's third-party controls provide a variety of tree controls with checkboxes, such as tadvchecktreeview, trzchecktree, etc.:

Embedded assembly (including assembler block, assembler function subroutine, assembly process body subroutine) should be supported in Delphi, and embedded development should be supported, such as data acquisition, automatic control, etc.

If you have a high requirement for real-time control and are in an x86 environment, it is recommended to use MSDOS Turbo Pascal for embedded development.

First of all, it should be noted that there is no way to apply the label to the memo.

If there are two memos, you can do the following:

Impossible.........Delphi can only be selected with the right-click menu, .......

You give 200,000 and ask Borland's engineer to help you add this feature to the Delphi Ide.