假设已经复制了3个字符串到UIPasteBoard中:
UIPasteboard.generalPasteboard().string="hello"
UIPasteboard.generalPasteboard().string="world"
UIPasteboard.generalPasteboard().string="!"
我使用UIPasteboard.generalPasteboard().string=""
这会清空剪贴板吗?是否有类似于NSPasteBoard的clearContents()函数的UIPasteBoard函数?