对于有输入功能的控件，例如UITextField，可以给控件的inputView属性赋值，实现自定义键盘的功能
UIView *view = [[UIView alloc]initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, 300)];
UIButton *button = [[UIButton alloc]initWithFrame:CGRectMake(10, 10, 50, 50)];
[button setTitle:@"1" forState:UIControlStateNormal];
button.backgroundColor = [UIColor whiteColor];
[button setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[view addSubview:button];
[button addTarget:self action:@selector(touchAction) forControlEvents:UIControlEventTouchUpInside];
_textField.inputView = view;
也可以给控件的inputAccessoryView赋值UIToolbar的对象设置工具条。
如果结合第三方键盘监听事件的库IQKeyboard的话，效果更好。
