模仿闲鱼里面价格输入的键盘控件，图片来源支付宝内数字键盘。
- import CWNumberKeyboard folder
#import "CWNumberKeyboard.h"- use
if (!_numberKb) {
_numberKb = [[CWNumberKeyboard alloc] init];
[self.view addSubview:_numberKb];
}
[_numberKb setHidden:NO];
[_numberKb showNumKeyboardViewAnimateWithPrice:self.mPriceLabel.text andBlock:^(NSString *priceString) {
self.mPriceLabel.text = priceString;
}];