在obj c中通过编程实现吗

UIView *view = [[UIView alloc] initWithFrame:CGRectMake(20, 50,    200, 200)];

view.layer.backgroundColor = [UIColor whiteColor].CGColor;
view.layer.cornerRadius = 20.0;
view.layer.frame = CGRectInset(v.layer.frame, 20, 20);

[view.layer.shadowOffset = CGSizeMake(1, 0);
view.layer.shadowColor = [[UIColor blackColor] CGColor];
view.layer.shadowRadius = 5;
view.layer.shadowOpacity = .25;][1]

[self.view addSubview:view];

我们也可以从stoaryboard做这个。

 layer.cornerRadius  Number  5

请导入Quartzcore框架，然后你必须设置setMaskToBounds为TRUE，这是非常重要的一行。

然后:[[yourView layer] setCornerRadius:5.0f];

在Swift 4.2和Xcode 10.1中

let myView = UIView()
myView.frame = CGRect(x: 200, y: 200, width: 200, height: 200)
myView.myViewCorners()
//myView.myViewCorners(width: myView.frame.width)//Pass View width
view.addSubview(myView)

extension UIView {
    //If you want only round corners
    func myViewCorners() {
        layer.cornerRadius = 10
        layer.borderWidth = 1.0
        layer.borderColor = UIColor.red.cgColor
        layer.masksToBounds = true
    }
    //If you want complete round shape, enable above comment line
    func myViewCorners(width:CGFloat) {
        layer.cornerRadius = width/2
        layer.borderWidth = 1.0
        layer.borderColor = UIColor.red.cgColor
        layer.masksToBounds = true
    }
}

在obj c中通过编程实现吗

UIView *view = [[UIView alloc] initWithFrame:CGRectMake(20, 50,    200, 200)];

view.layer.backgroundColor = [UIColor whiteColor].CGColor;
view.layer.cornerRadius = 20.0;
view.layer.frame = CGRectInset(v.layer.frame, 20, 20);

[view.layer.shadowOffset = CGSizeMake(1, 0);
view.layer.shadowColor = [[UIColor blackColor] CGColor];
view.layer.shadowRadius = 5;
view.layer.shadowOpacity = .25;][1]

[self.view addSubview:view];

我们也可以从stoaryboard做这个。

 layer.cornerRadius  Number  5

如果圆角在viewDidload()中不起作用，最好在viewDidLayoutSubview()中编写代码

-(void)viewDidLayoutSubviews
{
    viewTextfield.layer.cornerRadius = 10.0 ;                                               
    viewTextfield.layer.borderWidth = 1.0f;
    viewTextfield.layer.masksToBounds =  YES;
    viewTextfield.layer.shadowRadius = 5;
    viewTextfield.layer.shadowOpacity = 0.3;
    viewTextfield.clipsToBounds = NO;
    viewTextfield.layer.shadowOffset = CGSizeMake(0.0f, 0.0f);
}

希望这能有所帮助!

你也可以使用图像:

UIImage *maskingImage = [UIImage imageNamed:@"bannerBarBottomMask.png"];
CALayer *maskingLayer = [CALayer layer];
maskingLayer.frame = CGRectMake(-(self.yourView.frame.size.width - self.yourView.frame.size.width) / 2
                                , 0
                                , maskingImage.size.width
                                , maskingImage.size.height);
[maskingLayer setContents:(id)[maskingImage CGImage]];
[self.yourView.layer setMask:maskingLayer];