iphone - 如何使用 UITouch 移动铅笔图像？

Question

我想使用 UITouch 移动铅笔图像？我想移动铅笔，它会写我们想要的任何东西。

但我无法移动和书写铅笔图像。

专家的任何提示都将非常受欢迎。

Answer 1

以下代码用于在您触摸时移动图像

AppDelegate Classes

**// .h File**

#import <UIKit/UIKit.h>

@class UITouchTutorialViewController;

@interface UITouchTutorialAppDelegate : NSObject <UIApplicationDelegate> {
    UIWindow *window;
    UITouchTutorialViewController *viewController;
}

@property (nonatomic, retain) IBOutlet UIWindow *window;
@property (nonatomic, retain) IBOutlet UITouchTutorialViewController *viewController;

@end

//////////////////////////////////////////////////////////////////////////////////

// .m File

#import "UITouchTutorialAppDelegate.h"
#import "UITouchTutorialViewController.h"

@implementation UITouchTutorialAppDelegate

@synthesize window;
@synthesize viewController;


- (void)applicationDidFinishLaunching:(UIApplication *)application {    

    // Override point for customization after app launch    
    [window addSubview:viewController.view];
    [window makeKeyAndVisible];
}


- (void)dealloc {
    [viewController release];
    [window release];
    [super dealloc];
}


@end
//////////////////////////////////////////////////////////////////////////////

UIViewController Classes

// .h file

#import <UIKit/UIKit.h>

@interface UITouchTutorialViewController : UIViewController {
    IBOutlet UIImageView *cloud;
}

@end

// .m File

#import "UITouchTutorialViewController.h"

@implementation UITouchTutorialViewController

-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [[event allTouches] anyObject];
    CGPoint location = [touch locationInView:touch.view];
    cloud.center = location;
}

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    [self touchesBegan:touches withEvent:event];
}

/*
// Override initWithNibName:bundle: to load the view using a nib file then perform additional customization that is not appropriate for viewDidLoad.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
        // Custom initialization
    }
    return self;
}
*/

/*
// Implement loadView to create a view hierarchy programmatically.
- (void)loadView {
}
*/


/*
// Implement viewDidLoad to do additional setup after loading the view.
- (void)viewDidLoad {
    [super viewDidLoad];
}
*/


- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    // Return YES for supported orientations
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}


- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning]; // Releases the view if it doesn't have a superview
    // Release anything that's not essential, such as cached data
}


- (void)dealloc {
    [super dealloc];
}

@end

Answer 2

使用这些方法：

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

  UITouch *touch = [touches anyObject];
  CGPoint currentPoint = [touch locationInView:self];
  yourPencilImgView.center = [touch locationInView:self];
}

和

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

  UITouch *touch = [touches anyObject];
  CGPoint currentPoint = [touch locationInView:self];
  yourPencilImgView.center  = currentPoint;
}

Answer 3

您可以使用UIPanGestureRecognizer

- (void)onDraggingPencil:(UIPanGestureRecognizer *)panGR {

     CGPoint translation = [panGR translationInView:baseView];

     if (panGR.state == UIGestureRecognizerStateBegan) {

     } else if (panGR.state == UIGestureRecognizerStateChanged) {  

        CGRect _rect = panGR.view.frame;
        _rect.origin.x = dragPoint.x + translation.x;
        _rect.origin.y = dragPoint.y + translation.y;
        panGR.view.frame = _rect;

    } else if (panGR.state == UIGestureRecognizerStateEnded) {

    }
}

Answer 4

您可以使用以下代码拖放图像

UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(move:)];
[panRecognizer setMinimumNumberOfTouches:1];
[panRecognizer setMaximumNumberOfTouches:1];
[panRecognizer setDelegate:self];
[imageView_ addGestureRecognizer:panRecognizer];

-(void)move:(id)sender {

CGPoint translatedPoint = [(UIPanGestureRecognizer*)sender translationInView:self.view];

if([(UIPanGestureRecognizer*)sender state] == UIGestureRecognizerStateBegan) {

    firstX = [[sender view] center].x;
    firstY = [[sender view] center].y;
}

translatedPoint = CGPointMake(firstX+translatedPoint.x, firstY+translatedPoint.y);
[[sender view] setCenter:translatedPoint];

}