学步园

      首先我们需要了解MVC模式（Model-View-Controller）。也许有些人和我一样，以前学过WEB开发。

所以对MVC比较了解。但是真正运用开发时只知道其中的实现。对于具体的理论我就不做过多的介绍。

效果如图所示：

当我们点击onClick按钮时会改变上面Label的内容。
代码如下：

 首先在TestAlertViewController 中声明两个变量。也就是button和label；

然后在声明一个方法，是点击按钮时触发事件所要处理的方法

#import "MyAlertView.h"
#import <UIKit/UIKit.h>

@interface TestAlertViewController : UIViewController {
	UIButton *myButton;
	UILabel *myLabel;
}
@property (nonatomic, retain) UIButton *myButton;
@property (nonatomic, retain) UILabel *myLabel;
-(IBAction) buttonPress:(id)sender;
@end

在TestAlertViewController 实例化两个变量。并完成处理事件的方法。

-(IBAction) buttonPress:(id)sender {
     myLabel.text = @"onClick myButton!";
}

- (void)viewDidLoad {
	myButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
	myButton.frame = CGRectMake(120, 220, 80, 40);
	[myButton setBackgroundColor:[UIColor blueColor]];
	[myButton setTitle:@"onClick" forState:UIControlStateNormal];
	[myButton addTarget:self action:@selector(buttonPress:) forControlEvents:UIControlEventTouchUpInside];

//添加myButton处理事件的方法。
	[self.view addSubview:myButton];
	myLabel = [[UILabel alloc] initWithFrame:CGRectMake(90, 50, 140, 40)];
	myLabel.textAlignment = UITextAlignmentCenter;
	myLabel.text = @"HelloWorld";
	[self.view addSubview:myLabel];
    [super viewDidLoad];
}



- (void)viewDidLoad {
	myButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
	myButton.frame = CGRectMake(120, 220, 80, 40);
	[myButton setBackgroundColor:[UIColor blueColor]];
	[myButton setTitle:@"onClick" forState:UIControlStateNormal];
	[myButton addTarget:self action:@selector(buttonPress:) forControlEvents:UIControlEventTouchUpInside];
	[self.view addSubview:myButton];
	myLabel = [[UILabel alloc] initWithFrame:CGRectMake(90, 50, 140, 40)];
	myLabel.textAlignment = UITextAlignmentCenter;
	myLabel.text = @"HelloWorld";
	[self.view addSubview:myLabel];
    [super viewDidLoad];
}

 
 
 
 

- (void)viewDidLoad {
	myButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
	myButton.frame = CGRectMake(120, 220, 80, 40);
	[myButton setBackgroundColor:[UIColor blueColor]];
	[myButton setTitle:@"onClick" forState:UIControlStateNormal];
	[myButton addTarget:self action:@selector(buttonPress:) forControlEvents:UIControlEventTouchUpInside];
	[self.view addSubview:myButton];
	myLabel = [[UILabel alloc] initWithFrame:CGRectMake(90, 50, 140, 40)];
	myLabel.textAlignment = UITextAlignmentCenter;
	myLabel.text = @"HelloWorld";
	[self.view addSubview:myLabel];
    [super viewDidLoad];
}