在delphi/lazarus中搜索已放入记录数组的记录

Question

我有一个包含许多记录的数组。像这样设置：

Tcustomer= record
  Name: string[40];
  Address: string[100];
  phone: string[15];
  email:string[50]; 
end;

现在，假设我想在这个数组中搜索具有特定姓名和地址的人。我该怎么办？所以基本上搜索不仅仅是1个元素。（我可以专门搜索 1 个属性，但不能过滤超过 1 个）

附件是我的表单如何设置的图片，这将更详细地显示我所指的内容：

Answer 1

您只需迭代数组并检查循环中记录的多个属性。这是一个在姓名、地址、电话或电子邮件中搜索匹配项的示例；要将其更改为在多个记录属性（如名称和地址）中查找匹配项，只需or使用两个或多个测试替换测试中的子句and，如if (Customers[Idx].Name = Name) and (Customers[Idx].Address = Address) then.

type
  TCustomer = record
    Name: string[40];
    Address: string[100];
    Phone: string[15];
    Email:string[50]; 
  end;

  TCustomerList: array of TCustomer;

function FindCustomer(const Name, Address, EMail,
  Phone: string; const Customers: TCustomerList): Integer;
var
  i: Integer;
begin
  Result := -1;                           // Value if no match found
  for i := Low(Customers) to High(Customers) do
  begin
    if (Customers[i].Name = Name) or        // Name matches?
       (Customers[i].Address = Address) or  // Address?
       (Customers[i].EMail = EMail) or      // Same email?
       (Customers[i].Phone = Phone) then    // Same phone
      begin
        Result := i;                        // Yep. We have a match.
        Exit;                               // We're done.
      end;
  end;
end;

样品用途：

var
  Idx: Integer;
begin
  // Customers is your array of TCustomer in a TCustomerList
  Idx := FindCustomer('', '', '', 'jsmith@example.com', Customers);
  if (Idx = -1) then
    WriteLn('No match found.')
  else
    WriteLn(Format('Customer %d: %s %s %s %s',
                   [Idx, 
                    Customers[Idx].Name,
                    Customers[Idx].Address,
                    Customers[Idx].Phone,
                    Customers[Idx].EMail]));
end;

要匹配值的组合（例如Name和Address），只需if适当更改条件：

function FindCustomerByNameAndAddress(const Name, Address: string; 
  const Customers: TCustomerList): Integer;
var
  i: Integer;
begin
  Result := -1;                           // Value if no match found
  for i := Low(Customers) to High(Customers) do
  begin
    if (Customers[i].Name = Name) then          // Name matches.
      if (Customers[i].Address = Address) then  // Does address?
      begin
        Result := i;                            // Yep. We found it
        Exit;                               
      end;
  end;
end;

样品用途：

Idx := FindCustomerByNameAndAddress('John Smith', '123 Main Street`);
if Idx = -1 then
  // Not found
else
  // Found. Same code as above to access record.