UITouch对象应用实例-触摸跟随特效，在ViewController中控制管理view接收的touch事件

////EventReporter10ViewController中的代码

#import <UIKit/UIKit.h>
@interface EventReporter10ViewController : UIViewController {
//在IB中创建一下四个控件，用来检测touch数据
IBOutlet UITextField *startField;
IBOutlet UITextField *endField;
IBOutlet UITextField *moveField;
IBOutlet UILabel *bottomLabel;
UIView *box;
}
-(void)manageTouches:(NSSet*)touches;
-(void)dragView:(UIView*)aView withPoint:(CGPoint)point;
-(void)touchMoveWithPoint:(CGPoint)touchPos;
@end

#import "EventReporter10ViewController.h"
@implementation EventReporter10ViewController

////下面一个方法是利用在ReportView中获取到的touchs集合去控制程序中的各个元素做各种事情。下面的代码实现了一个类似于鼠标跟随的触摸跟随特效；

-(void)manageTouches:(NSSet*)touches{
for (UITouch *touch in touches) {
if (touch.phase == UITouchPhaseBegan) {
CGPoint touchPos = [touch locationInView:self.view];
startField.text =[NSString stringWithFormat:@"Begin:%3.0f,%3.0f",touchPos.x,touchPos.y];
}else if(touch.phase == UITouchPhaseMoved){
bottomLabel.text = @"Touch 正在移动中...";
CGPoint touchPos = [touch locationInView:self.view];
moveField.text = [NSString stringWithFormat:@"move:%3.0f,%3.0f",touchPos.x,touchPos.y];

[self touchMoveWithPoint:touchPos];

}else if(touch.phase == UITouchPhaseEnded){
if (touch.tapCount>1) {
bottomLabel.text = [NSString stringWithFormat:@"Taps:%2i",touch.tapCount];
}else{
bottomLabel.text = @"等待交互...";
}
CGPoint touchPos = [touch locationInView:self.view];
endField.text = [NSString stringWithFormat:@"End:%3.0f,%3.0f",touchPos.x,touchPos.y];

}
}
}

-(void)touchMoveWithPoint:(CGPoint)touchPos{
UIView *aview = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 3, 3)];
[aview setBackgroundColor:[UIColor redColor]];
[self.view addSubview:aview];
[aview release];

[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.5];
[aview setAlpha:0.0];
[UIView commitAnimations];

[self dragView:aview withPoint:touchPos];

if ([[self.view subviews] count]>50) {
[[[self.view subviews] objectAtIndex:4] removeFromSuperview];
}
}
-(void)dragView:(UIView*)aView withPoint:(CGPoint)point{
aView.center = point;
}

- (void)dealloc
{
[startField release];
[endField release];
[moveField release];
[bottomLabel release];
[super dealloc];
}
- (void)viewDidLoad
{
[super viewDidLoad];
}
@end

////以下代码是创建UIView子类ReportView，将EventReporter10ViewController控制的View变成ReportView（它的子类），添加四个获取touchs集合的方法，

////并将集合通过manageTouches:touches方法传递给EventReporter10ViewController,这里使用的self.nextResponder获取其ViewController的指针

#import <UIKit/UIKit.h>
@class EventReporter10ViewController;
@interface ReportView : UIView {
}
@end

#import "ReportView.h"
#import "EventReporter10ViewController.h"
@implementation ReportView

////ViewController就是本ReportView的nextResponder
////以下方法是将获取到的NSSet *touches集合 传给 ViewController，
////这样就可以在ViewController里面接收ReportView的touch事件,并以此对ReportView控制或其他对象进行控制

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
EventReporter10ViewController *mainViewController = (EventReporter10ViewController *)self.nextResponder;
[mainViewController manageTouches:touches];
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
EventReporter10ViewController *mainViewController = (EventReporter10ViewController *)self.nextResponder;
[mainViewController manageTouches:touches];
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
EventReporter10ViewController *mainViewController = (EventReporter10ViewController *)self.nextResponder;
[mainViewController manageTouches:touches];
}

- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
}
return self;
}
- (void)dealloc
{
[super dealloc];
}

@end