Introduction
In this article I will create an Empty View application. We create an entire app using code. I mean we doesn't use an xib file here. In this app we make a rounded button and do an action on it.
To understand it we use the following.
Step 1
Open XCode by double-clicking on it.
Step 2
Create a New XCode Project by clicking on it.
Step 3
Now Select Empty View Application and click on Next.
Step 4
Now provide your Product Name and Company Identifier.
Step 5
Select the location where you want to save your project and click on Create.
Step 6
First we import the framework "QuartzCore" that is required.
Framework-in-iPhone.png

Step 7
Now here we write code:
AppDelegate.h
  1. #import <UIKit/UIKit.h>
  2. #import <QuartzCore/QuartzCore.h>
  3. @interface AppDelegate : UIResponder <UIApplicationDelegate>
  4. @property(strong,nonatomic) UIButton *btn1,*btn2,*btn3;
  5. @property (strong, nonatomic) UIView *lineView1,*lineView2,*lineView3,*lineView4;
  6. @property (strong, nonatomic) UIWindow *window;
  7. @end
MapAppDelegate.m
  1. #import "AppDelegate.h"
  2. @implementation AppDelegate
  3. @synthesize btn1,btn2,btn3,lineView1,lineView2,lineView3,lineView4;
  4. - (void)dealloc
  5. {
  6. [_window release];
  7. [super dealloc];
  8. }
  9. -(void)click1
  10. {
  11. [btn1 setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
  12. [btn1 setTitle:@"I" forState:UIControlStateNormal];
  13. }
  14. -(void)click2
  15. {
  16. [btn2 setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
  17. [btn2 setTitle:@"Love" forState:UIControlStateNormal];
  18. }
  19. -(void)click3
  20. {
  21. [btn3 setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
  22. [btn3 setTitle:@"India" forState:UIControlStateNormal];
  23. }
  24. -(void)click{
  25. lineView1 = [[UIView alloc] initWithFrame:CGRectMake(85, 90, 198, 10)];
  26. lineView1.backgroundColor = [UIColor blackColor];
  27. [self.window addSubview:lineView1];
  28. [lineView1 release];
  29. lineView2 = [[UIView alloc] initWithFrame:CGRectMake(100, 100, 10, 80)];
  30. lineView2.backgroundColor = [UIColor blackColor];
  31. [self.window addSubview:lineView2];
  32. [lineView2 release];
  33. lineView3 = [[UIView alloc] initWithFrame:CGRectMake(185, 100, 10, 200)];
  34. lineView3.backgroundColor = [UIColor blackColor];
  35. [self.window addSubview:lineView3];
  36. [lineView3 release];
  37. lineView4 = [[UIView alloc] initWithFrame:CGRectMake(273, 100, 10, 300)];
  38. lineView4.backgroundColor = [UIColor blackColor];
  39. [self.window addSubview:lineView4];
  40. [lineView4 release];
  41. btn1 = [[UIButton alloc]initWithFrame:CGRectMake(65,180,80,80 )];
  42. btn1.backgroundColor = [UIColor greenColor];
  43. btn1.layer.cornerRadius = 80/2;
  44. [btn1 addTarget:self action:@selector(click1) forControlEvents:UIControlEventTouchUpInside];
  45. [self.window addSubview:btn1];
  46. btn2 = [[UIButton alloc]initWithFrame:CGRectMake(150,280,80,80 )];
  47. btn2.backgroundColor = [UIColor redColor];
  48. btn2.layer.cornerRadius = 80/2;
  49. [btn2 addTarget:self action:@selector(click2) forControlEvents:UIControlEventTouchUpInside];
  50. [self.window addSubview:btn2];
  51. btn3 = [[UIButton alloc]initWithFrame:CGRectMake(238,398,80,80 )];
  52. btn3.backgroundColor = [UIColor purpleColor];
  53. btn3.layer.cornerRadius = 80/2;
  54. [btn3 addTarget:self action:@selector(click3) forControlEvents:UIControlEventTouchUpInside];
  55. [self.window addSubview:btn3];
  56. }
  57. - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
  58. {
  59. self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
  60. // Override point for customization after application launch.
  61. self.window.backgroundColor = [UIColor whiteColor];
  62. UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
  63. [button setImage:[UIImage imageNamed:@"Sachin.png"] forState:UIControlStateNormal];
  64. button.frame = CGRectMake(5.0, 50.0, 80.0, 80.0);//width and height should be same value
  65. button.clipsToBounds = YES;
  66. button.layer.cornerRadius = 40;//half of the width
  67. button.layer.borderColor=[UIColor yellowColor].CGColor;
  68. button.layer.borderWidth=3.0f;
  69. [button addTarget:self action:@selector(click) forControlEvents:UIControlEventTouchUpInside];
  70. [self.window addSubview:button];
  71. [self.window makeKeyAndVisible];
  72. return YES;
  73. }
  74. @end
Step 8
Finally we click on the run button to show the output.
Output
Output 1 in iPhone:

Output1-in-iPhone.png

When we click on this image view button, the Path with rounded buttons will be shown.
Output 2 in iPhone:

Output2-in-iPhone.png

Here the rounded button with path is shown.
Output 3 in iPhone:
Output3-in-iPhone.png
When we click on the Green button, an "I" will be shown on it.
Output 4 in iPhone:
Output4-in-iPhone.png
Here when we click on the Red button "love" will be shown on it.
Output 5 in iPhone:
Output5-in-iPhone.png
Here when we click on the Purple button "India" will be shown on it.