DataReader和DataSet的有哪些异同?
创建一个“文件读写”窗体。在窗体上添加2个命令按钮:“创建文件”和“读取文件”,再添加1个文本框。当点击“创建文件”按钮时,在D盘中的“测试”文件夹中创建一个文件temp2.dat,并将一个整数和字符串写入到temp.dat文件中去;当单击“读取文件”按钮时,在文本框中以字节的形式显示之前创建文件的内容,然后从文件中读取先前写入的整数和字符串,接着显示字符串所对应的二进制数据,最后将文件删除。
We've got plenty of time. We _____hurry.
A. can't
B. couldn't
C. wouldn't
D. needn't
He didn't answer when I called—he _____to bed.
A. would have gone
B. must have gone
C. will have gone
D. shall have gone