ios - 在ViewDidLoad 里添加UIButton的点击事件，不能触发。

Question

UIButton *btn2 = [[UIButton alloc] initWithFrame:CGRectMake(0, 38, 100, 38)];
[btn2 setTitle:@"添加好友" forState:UIControlStateNormal]; btn2.titleLabel.font = [UIFont systemFontOfSize:16];
[btn2 addTarget:self action:@selector(btn2Click:) forControlEvents:UIControlEventTouchDown];

之前可以触发， 现在不知是何原因不能触发了？

Answer 1

先更改

[btn2 addTarget:self action:@selector(btn2Click:) forControlEvents:UIControlEventTouchUpInside];

這樣還不行的話，檢查下父視圖的屬性 User Interaction Enabled,或查看btn2Click:方法

Answer 2

改成如下程式碼再試試

UIButton *btn2 = [[UIButton alloc] initWithFrame:CGRectMake(0, 38, 100, 38)];
[btn2 setTitle:@"添加好友" forState:UIControlStateNormal]; btn2.titleLabel.font = [UIFont systemFontOfSize:16];
[btn2 addTarget:self action:@selector(btn2Click:) forControlEvents:UIControlEventTouchUpInside];

Answer 3

這樣寫不對嗎？為什麼時好時壞？

Answer 4

麻煩 forControlEvents 的列舉改成：
UIControlEventTouchUpInside
另外button 有intrinctSize。你是否點在這個範圍內