UITextView阴影不起作用

Question

I am trying to get a UITextView's layer's shadow to work in a UITableView header. I have a UIView that I am formatting everything in, and then setting the headerview equal to it.

UIView * view = [[UIView alloc] initWithFrame: CGRectMake(0, 0, self.tableView.frame.size.width, 450);
UIColor * baseColor = [[UIColor alloc] initWithRed: 45/255.0
                                             green: 100/255.0
                                              blue: 150/255.0
                                             alpha: 1.0];

view.backgroundColor = baseColor;
...
UITextView * newCommentField = [[UITextView alloc] initWithFrame:CGRectMake(20, 230, 270,   120)];
newCommentField.text = @"New Comment";
newCommentField.tag = 3;
newCommentField.layer.shadowOffset = CGSizeMake(0, 3);
newCommentField.layer.shadowRadius = 5.0;
newCommentField.layer.shadowColor = [UIColor blackColor].CGColor;
newCommentField.layer.shadowOpacity = 0.8;
[view addSubview:newCommentField];
...
self.tableView.tableHeaderView = view;

Everything shows up properly in the view. However, the shadow is not appearing. I don't know what is going wrong here. I have even tried modifying the layer's frame and making it the size of the comment field, bigger and the same size.

Answer 1

You're not setting background color for newCommentField. Try:

newCommentField.backgroundColor = [UIColor whiteColor];

Answer 2

You can do it this way also... Create a view (eg. bgView) of same size as your textView and add that textView as a subView of bgView, which will be added as subView of you header view. Apply the shadow effect to the bgView instead.

UIView *bgView=[[UIView alloc]initWithFrame:CGRectMake(20, 230, 270,   120)];
bgView.backgroundColor=[UIColor whiteColor];
bgView.layer.shadowOffset = CGSizeMake(0, 3);
bgView.layer.shadowRadius = 5.0;
bgView.layer.shadowColor = [UIColor blackColor].CGColor;
bgView.layer.shadowOpacity = 0.8;

[bgView addSubview:newCommentField];

[view addSubview:bgView];