iOS UISeachBar键盘消失 虚拟按钮

    UIToolbar * topView = [[UIToolbar alloc]initWithFrame:CGRectMake(0, 0, 320, 30)];
    [topView setBarStyle:UIBarStyleBlackTranslucent];

    
    UIBarButtonItem * btnSpace = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:self action:nil];

    
    UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
    btn.frame = CGRectMake(2, 5, 50, 25);
    [btn addTarget:self action:@selector(dismissKeyBoard) forControlEvents:UIControlEventTouchUpInside];
    [btn setImage:[UIImage imageNamed:@"shouqi"] forState:UIControlStateNormal];
    UIBarButtonItem *doneBtn = [[UIBarButtonItem alloc]initWithCustomView:btn];
    NSArray * buttonsArray = [NSArray arrayWithObjects:btnSpace,doneBtn,nil];
    [topView setItems:buttonsArray];
    [_seachbar setInputAccessoryView:topView];

-(void)dismissKeyBoard
{
    [_seachbar resignFirstResponder];
}