In contrast, to make an independent copy of a dynamic array, you must use the global Copy function." "In some (???
) function and procedure declarations, array parameters are represented as array of base Type, without any index types specified.
The important point is freeing the object from memory, or your application will leak memory.
There are three ways to handle this: Declare a variable, call the class' Create() method, and end with Free(), preferably in a try/finally structure: A second way is to use the With structure, and set the instance's owner as a form, so that, even if you forgot to call Free, Delphi will free the object from memory when it kills the parent form (Actually, you should NOT call Free, and let the owner free the instance from memory): Note that the time to dynamically create components with owners is much slower than that to create components without owners. Here's how to read each line of a tab-delimited text file, and save this into an SQLite database: At design-time, the best way to add radio buttons to a form is by first adding a radiogroup object, and modify its Items property to add radio buttons.
That's the reason why some components are distributed as source code that you must compile yourself into a package before adding it to the IDE.
The alternative for commercial components is to generate multiple versions of the package, one for each version of the IDE that they wish to support.
DPR file), while the forms (windows) are described in files with the DFM extension, ie. Here's a skeleton of a unit: Open a DOS box, compile the program with "dcc32console", and run the compiled as with "console.exe".
In the empty form that shows up when starting Delphi, add a label and a pushbutton, double-click on the button, and add the following code to the Button1Click() routine: Hit F9 to run the application, and click on the pushbutton to see the text of the label change.
Dynamic arrays are automatically released when their reference-count drops to zero." "If X and Y are variables of the same dynamic-array type, X := Y points X to the same array as Y.
Unlike strings and static arrays, COPY-ON-WRITE is not employed for dynamic arrays, so they are not automatically copied before they are written to.
Components can be distributed either as Typically, commercial components are provided as binary files, but some can also be bought with source files. PAS or DCU files) can be added to an existing package, or to a brand new package through either File Install Component (when adding to an existing package, the default file is DCLUSR. A package file has the extension BPL, and is just a Borland-specific version of a DLL with added functions like Get Package Info Table(), ie.
routines that live in a file separate from the caller EXE, and that can be loaded dynamically when needed. EXE command-line Borland utility to display information containted in a BPL file.
With D7 at least, Delphi's Message Dlg doesn't let you select a default button, which is unfortunate for critical choices.