怎么根据字符串长度来定控件Width?
Edit2->Width = Edit2->Text.Length()*n

控件宽度 与 字符串长度好象不成比例关系。
[解决办法]
我帮你写一个函数来搞定：

void __fastcall CrnAdjustEditWidth(TEdit *edt)
{
    TControlCanvas *cc = new TControlCanvas();

    cc->Font->Assign(edt->Font);
    cc->Control = edt;
    edt->Width = cc->TextWidth(edt->Text) + 8;

    delete cc;
}

// ---------------------------------------
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    Edit1->Text = "123";
    CrnAdjustEditWidth(Edit1);
}

// ---------------------------------------
void __fastcall TForm1::Button2Click(TObject *Sender)
{
    Edit1->Text = "12fadsfdsafdsfdsa3";
    CrnAdjustEditWidth(Edit1);
}

// ---------------------------------------
void __fastcall TForm1::Button3Click(TObject *Sender)
{
    Edit1->Text = "CSDN论坛";
    CrnAdjustEditWidth(Edit1);
}