Исключения Delphi

// Проследите фактическое поведение ExceptChoice.
program ExceptChoice;
{$APPTYPE CONSOLE}
uses System.SysUtils;
begin
  try
    Writeln(StrToInt('12x'));
  except
    on E: EConvertError do
      Writeln('bad number: ', E.Message);
  end;
end.

// Отделите правило языка от удачного запуска DiagnosticContext.
program DiagnosticContext;
{$APPTYPE CONSOLE}
uses System.SysUtils;
procedure ImportFile(const FileName: string);
begin
  try
    raise EConvertError.Create('line 17');
  except
    on E: Exception do
      raise EConvertError.CreateFmt('Import %s failed: %s', [FileName, E.Message]);
  end;
end;
begin end.

// Определите реальную гарантию в NestedResources.
program NestedResources;
{$APPTYPE CONSOLE}
uses System.Classes;
var
  Input, Output: TFileStream;
begin
  Input := TFileStream.Create('a.bin', fmOpenRead);
  try
    Output := TFileStream.Create('b.bin', fmCreate);
    try
      Output.CopyFrom(Input, 0);
    finally
      Output.Free;
    end;
  finally
    Input.Free;
  end;
end.

// Предметное исключение публикует структурированные данные только для чтения.
program DomainException;
{$APPTYPE CONSOLE}
uses System.SysUtils;
type
  EInsufficientFunds = class(Exception)
  private
    FBalance, FRequested: Currency;
  public
    constructor Create(ABalance, ARequested: Currency);
    property Balance: Currency read FBalance;
    property Requested: Currency read FRequested;
  end;
constructor EInsufficientFunds.Create(ABalance, ARequested: Currency);
begin
  FBalance := ABalance;
  FRequested := ARequested;
  inherited CreateFmt('Balance %.2f, requested %.2f', [ABalance, ARequested]);
end;
begin
  try
    raise EInsufficientFunds.Create(25, 40);
  except
    on E: EInsufficientFunds do
      Writeln(E.Balance:0:2, ' ', E.Requested:0:2);
  end;
end.

// finally освобождает ресурс, но не перехватывает исключение.
program FinallyFlow;
{$APPTYPE CONSOLE}
uses System.Classes, System.SysUtils;
var
  S: TStringList;
begin
  S := TStringList.Create;
  try
    raise EReadError.Create('read failed');
  finally
    S.Free;
  end;
  Writeln('after');
end.