button点击无反应

{
UIImageView *rjUnpBagV=[[UIImageView alloc]initWithFrame:Frame(0, 0, ScreenWidth, ScreenHeight)];
self.rjUnpBagV.backgroundColor=[UIColor whiteColor];
[self.view addSubview:self.rjUnpBagV];
UIButton *rjPublishBtn=[UIButton buttonWithType:UIButtonTypeSystem];
rjPublishBtn.frame=Frame(ScreenWidth/4, rjUnpImgV.frame.origin.y+rjUnpImgV.frame.size.height+10, ScreenWidth/2, 30);
[rjPublishBtn setTitle:@"发布职位" forState:UIControlStateNormal];
[rjPublishBtn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
[rjPublishBtn setBackgroundColor:[UIColor colorWithRed:0.33 green:0.79 blue:0.76 alpha:1]];
[self.rjUnpBagV addSubview:rjPublishBtn];
[rjPublishBtn addTarget:self action:@selector(rjPublishBtnAction) forControlEvents:UIControlEventTouchUpInside];
}
-(void)rjPublishBtnAction{
    NSLog(@"点击");
}