基本觸控

#import <UIKit/UIKit.h>

@interface MyImageView : UIImageView{

    CGPoint startPoint;

}

@end

#import "MyImageView.h"

@implementation MyImageView

- (id)initWithFrame:(CGRect)frame

{

    self = [super initWithFrame:frame];

    if (self) {

        // Initialization code

    }

    return self;

}

-(id)initWithCoder:(NSCoder* )aDecoder{

    self = [super initWithCoder:aDecoder];

    if (self) {

        //啟動觸控

        self.userInteractionEnabled= YES;

        //設定圖檔

        self.image = [UIImage imageNamed:@"image4.jpg"];

    }

    return self;

}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{

    //取得觸控點

    CGPoint clickPoint = [[touches anyObject]locationInView:self];

    NSLog(@"觸控點在(%.1f,%.1f)",clickPoint.x,clickPoint.y);

    startPoint = clickPoint;

}

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{

    CGPoint clickPoint = [[touches anyObject]locationInView:self];

    //計算偏移值

    float offsetX = clickPoint.x - startPoint.x;

    float offsetY = clickPoint.y - startPoint.y;

    //設定新值並更新

    CGPoint newPoint = CGPointMake(self.center.x+offsetX, self.center.y+offsetY);

    self.center = newPoint;

    

}

/*

// Only override drawRect: if you perform custom drawing.

// An empty implementation adversely affects performance during animation.

- (void)drawRect:(CGRect)rect

{

    // Drawing code

}

*/

@end