A common beginner's question is how to use a scroll bar to scroll up and down large images or text blocks. The demo illustrates how it is done.
A common beginner's question is how to use a scroll bar to scroll up and down large images or text blocks. The demo illustrates how it is done.
这是初学者共有的一个疑问，如何使用滚动条来上下滚动大幅的图片或者文本块。这个程序演示了它是怎么实现的。