编写打印时出现的问题，急！ ( 积分: 30 )

for i := 1 to Data.ADOQMBooks.RecordCountdo
begin
Printer.Canvas.TextOut(200,500+i*80,
+Data.ADOQMBooks.FieldByName('BookID').AsString+' ' 报错行
+Data.ADOQMBooks.FieldByName('ISBN').AsString+' '
+Data.ADOQMBooks.FieldByName('BookName').AsString+' '
+Data.ADOQMBooks.FieldByName('BookType').AsString+' '
+Data.ADOQMBooks.FieldByName('BookAuthor').AsString+' '
+Data.ADOQMBooks.FieldByName('PublishName').AsString+' '
+Data.ADOQMBooks.FieldByName('PublishDate').AsString+' '
+Data.ADOQMBooks.FieldByName('PageCount').AsString+' '
+Data.ADOQMBooks.FieldByName('Keyword').AsString+' '
+Data.ADOQMBooks.FieldByName('RegisterDate').AsString+' '
+Data.ADOQMBooks.FieldByName('StockCount').AsString+' '
+Data.ADOQMBooks.FieldByName('Memo').AsString);
Data.ADOQMBooks.Next;
end;
运行时代码的+Data.ADOQMBooks.FieldByName('BookID').AsString+' '这一行报错，错误提示为Operator not applicable to this operand type，有谁知道这是怎么回事嘛？

for i := 1 to Data.ADOQMBooks.RecordCountdo
begin
Printer.Canvas.TextOut(200,500+i*80,
+Data.ADOQMBooks.FieldByName('BookID').AsString+' ' 报错行
+Data.ADOQMBooks.FieldByName('ISBN').AsString+' '
+Data.ADOQMBooks.FieldByName('BookName').AsString+' '
+Data.ADOQMBooks.FieldByName('BookType').AsString+' '
+Data.ADOQMBooks.FieldByName('BookAuthor').AsString+' '
+Data.ADOQMBooks.FieldByName('PublishName').AsString+' '
+Data.ADOQMBooks.FieldByName('PublishDate').AsString+' '
+Data.ADOQMBooks.FieldByName('PageCount').AsString+' '
+Data.ADOQMBooks.FieldByName('Keyword').AsString+' '
+Data.ADOQMBooks.FieldByName('RegisterDate').AsString+' '
+Data.ADOQMBooks.FieldByName('StockCount').AsString+' '
+Data.ADOQMBooks.FieldByName('Memo').AsString);
Data.ADOQMBooks.Next;
end;
运行时代码的+Data.ADOQMBooks.FieldByName('BookID').AsString+' '这一行报错，错误提示为Operator not applicable to this operand type，有谁知道这是怎么回事嘛？

没有人知道嘛？

晕
没人来
想结帖都不行

当然错了，开头多了个“+”

接受答案了.