Như với tất cả các thành phần, khi bạn thêm một thành phần trình đơn để tạo thành, hình thức cung cấp cho nó một tên mặc định, ví dụ, MainMenu1. Bạn có thể cung cấp cho các menu một tên có ý nghĩa hơn sau quy ước đặt tên ngôn ngữ. ông tên trình đơn được thêm vào để khai báo kiểu của hình thức, và tên đơn sau đó xuất hiện trong danh sách phần. | Handling exceptions in VCL applications Table Selected exception classes continued Exception class Description EDBEditError Catches data incompatible with a specified mask. EDivByZero Catches integer divide-by-zero errors. EExternalException Signifies an unrecognized exception code. ElnOutError Represents a file I O error. ElntOverflow Specifies integer calculations whose results are too large for the allocated register. EInvalidCast Checks for illegal typecasting. EInvalidGraphic Indicates an attempt to work with an unrecognized graphic file format. EInvalidOperation Occurs when invalid operations are attempted on a component. EInvalidPointer Results from invalid pointer operations. EMenuError Involves a problem with menu item. EOleCtrlError Detects problems with linking to ActiveX controls. EOleError Specifies OLE automation errors. EPrinterError Signals a printing error. EPropertyError Occurs on unsuccessful attempts to set the value of a property. ERangeError Indicates an integer value that is too large for the declared type to which it is assigned. ERegistryException Specifies registry errors. EZeroDivide Catches floating-point divide-by-zero errors. There are other times when you will need to create your own exception classes to handle unique situations. You can declare a new exCeption class by making it a descendant of type Exception and creating as many constructors as you need or copy the constructors from an existing class in the SysUtils unit . Default exception handling in VCL If your application code does not catch and handle the exceptions that are raised the exceptions are ultimately caught and handled by the HandleException method of the global Application object. For all exceptions but EAbort HandleException calls the OnException event handler if one exists. If there is no OnException event handler and the exception is not EAbort HandleException displays a message box with the error message associated with the exception. Exception handling .
