#import <UIKit/UIKit.h>
@interface ViewController : UIViewController
@property(strong,nonatomic) UIButton *btnTest;
@property(strong,nonatomic) UITextField *txtName;
@end
#import "ViewController.h"
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
self.btnTest=[UIButton buttonWithType:UIButtonTypeRoundedRect];
self.btnTest.frame=CGRectMake(100, 100, 150, 44);
[self.btnTest setTitle:@"按钮" forState:UIControlStateNormal];
[self.btnTest setBackgroundColor:[UIColor redColor]];
[self.btnTest addTarget:self action:@selector(testBtn) forControlEvents:UIControlEventTouchCancel];
[self.view addSubview:self.btnTest];
}
-(void)testBtn
{
NSString *name=self.txtName.text;
NSLog(@"%@",name);
NSLog(@"test");
int len=(int)self.txtName.text.length;
if (len==0)
{
NSLog(@"用户名不能为空");
}
else if (len>0&&len<8)
{
NSLog(@"长度不够");
}
else
{
NSLog(@"继续");
}
}
原文：http://www.cnblogs.com/tmf-4838/p/5256270.html