Incompatible types: 'string' and 'Double' - delphi-xe

Question

I would like to use a Label or a Memo to view information:
function GetCPUSpeed: Double;
const
DelayTime = 500;
var
TimerHi, TimerLo: DWORD;
PriorityClass, Priority: Integer;
begin
PriorityClass := GetPriorityClass(GetCurrentProcess);
Priority := GetThreadPriority(GetCurrentThread);
SetPriorityClass(GetCurrentProcess, REALTIME_PRIORITY_CLASS);
SetThreadPriority(GetCurrentThread, THREAD_PRIORITY_TIME_CRITICAL);
Sleep(10);
asm
dw 310Fh
mov TimerLo, eax
mov TimerHi, edx
end;
Sleep(DelayTime);
asm
dw 310Fh
sub eax, TimerLo
sbb edx, TimerHi
mov TimerLo, eax
mov TimerHi, edx
end;
SetThreadPriority(GetCurrentThread, Priority);
SetPriorityClass(GetCurrentProcess, PriorityClass);
Result := TimerLo / (1000 * DelayTime);
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
ShowMessage(Format('Your CPU speed: %f MHz', [GetCPUSpeed]));
Label1.caption := GetCPUSpeed;
Memo1.Lines := GetCPUSpeed;
end;
To use the Label or a Memo, I have to convert data into a string. How can I do that?
[DCC Error] speed_cpu.pas(62): E2010 Incompatible types: 'string' and 'Double'

Answer 1

First off, you can't assign a string to the TMemo.Lines property, which is a TStrings object. You would have to assign to either TMemo.Lines.Text or TMemo.Text instead.
As for the actual conversion, you already know one way to do it, via SysUtils.Format():
uses
..., SysUtils;
var
Speed: Double;
...
Speed := GetCPUSpeed;
ShowMessage(Format('Your CPU speed: %f MHz', [Speed]));
Label1.Caption := Format('%f', [Speed]);
Memo1.Text := Format('%f', [Speed]);
You can also use SysUtils.FloatToStr():
uses
..., SysUtils;
var
Speed: Double;
...
Speed := GetCPUSpeed;
ShowMessage(Format('Your CPU speed: %f MHz', [Speed]));
Label1.Caption := FloatToStr(Speed);
Memo1.Text := FloatToStr(Speed);
In XE4+, you can also use SysUtils.TDoubleHelper.ToString():
uses
..., SysUtils;
var
Speed: Double;
...
Speed := GetCPUSpeed;
ShowMessage(Format('Your CPU speed: %f MHz', [Speed]));
Label1.Caption := Speed.ToString;
Memo1.Text := Speed.ToString;

Answer 2

Thank you problem solved.
function Tipo_cpu: string;
var
aVendor: array[0..2] of DWord;
iI, iJ : Integer;
begin
asm
push ebx
xor eax, eax
dw $A20F // CPUID instruction
mov DWord ptr aVendor, ebx
mov DWord ptr aVendor[+4], edx
mov DWord ptr aVendor[+8], ecx
pop ebx
end;
for iI := 0 to 2 do
for iJ := 0 to 3 do
Result := Result + Chr((aVendor[iI] and ($000000FF shl (iJ * 8))) shr (iJ * 8));
end;
function GetCPUSpeed: Double;
const
DelayTime = 500;
var
TimerHi, TimerLo: DWORD;
PriorityClass, Priority: Integer;
begin
PriorityClass := GetPriorityClass(GetCurrentProcess);
Priority := GetThreadPriority(GetCurrentThread);
SetPriorityClass(GetCurrentProcess, REALTIME_PRIORITY_CLASS);
SetThreadPriority(GetCurrentThread, THREAD_PRIORITY_TIME_CRITICAL);
Sleep(10);
asm
dw 310Fh
mov TimerLo, eax
mov TimerHi, edx
end;
Sleep(DelayTime);
asm
dw 310Fh
sub eax, TimerLo
sbb edx, TimerHi
mov TimerLo, eax
mov TimerHi, edx
end;
SetThreadPriority(GetCurrentThread, Priority);
SetPriorityClass(GetCurrentProcess, PriorityClass);
Result := TimerLo / (1000 * DelayTime);
end;
procedure TForm1.FormCreate(Sender: TObject);
var
ids: TidIpWatch;
Speed: Double;
begin
ids := TidIpWatch.Create;
Speed := GetCPUSpeed;
Memo1.Text := 'IP:' + (ids.LocalIP);
Memo1.Text := (Tipo_cpu);
Memo1.Text := Format('%f', [Speed]);
ids.Free;
end;