限制UITextfield只能输入数字和小数点

在UITextfield代理shouldChangeCharactersInRange或者给UITextfield添加事件(UIControlEventEditingChanged)的方法中添加以下代码:

NSCharacterSet *characterSet = [[NSCharacterSet characterSetWithCharactersInString:@"0123456789."] invertedSet];//设置过滤的集合

NSString *filtered = [[sender.text componentsSeparatedByCharactersInSet:characterSet] componentsJoinedByString:@""];//过滤

sender.text = filtered;//赋值