var a1,a2,a3:double; begin a1:=StrToFloatdef(edit1.text,0); a2:=StrToFloatdef(edit2.text,0); if (trim(edit1.text)='')or(trim(edit.text)='') then exit; if (StrToFloat(Edit1.Text)>=0)and(StrToFloat(Edit2.Text)>=0) then begin a3:=a1-a2; edit.text:=trim(format('%12.2f',[a3])); end; end;
上面的错了...少加了2,3了..呵var a1,a2,a3:double; begin a1:=StrToFloatdef(edit1.text,0); a2:=StrToFloatdef(edit2.text,0); if (trim(edit1.text)='')or(trim(edit2.text)='') then exit; if (StrToFloat(Edit1.Text)>=0)and(StrToFloat(Edit2.Text)>=0) then begin a3:=a1-a2; edit3.text:=trim(format('%12.2f',[a3])); end; end;
a1,a2,a3:double;
begin
a1:=StrToFloatdef(edit1.text,0);
a2:=StrToFloatdef(edit2.text,0);
if (trim(edit1.text)='')or(trim(edit.text)='') then exit;
if (StrToFloat(Edit1.Text)>=0)and(StrToFloat(Edit2.Text)>=0) then
begin
a3:=a1-a2;
edit.text:=trim(format('%12.2f',[a3]));
end;
end;
a1,a2,a3:double;
begin
a1:=StrToFloatdef(edit1.text,0);
a2:=StrToFloatdef(edit2.text,0);
if (trim(edit1.text)='')or(trim(edit2.text)='') then exit;
if (StrToFloat(Edit1.Text)>=0)and(StrToFloat(Edit2.Text)>=0) then
begin
a3:=a1-a2;
edit3.text:=trim(format('%12.2f',[a3]));
end;
end;
一般不能加减,
所以str转换格式…
用StrToFloat(Edit1.Text)就可以了.