Question

我正在尝试创建一个程序，用户可以使用UIPanGestureRecognizer在屏幕上拖动UIImageView。我尝试了几种不同的方法，但无法弄明白。我不确定是否需要创建发件人/请求者。我的理解是UIImageView需要放在一个可以处理手势的UIView中。在我的程序中，我有一个视图控制器 - AdvancedViewController1。我创建了一个名为AdvancedView1的UIView。在界面生成器中，我已将AdvancedView1插入到AdvancedViewController 1中。以下是控制器和视图的.h和.m文件。我只包含了相关的代码。如果我很接近，请告诉我，以及如何修复我的代码。在此先感谢您的帮助。

AdvancedViewController1.h
#import <UIKit/UIKit.h>
#import "AdvancedView1.h"
@interface AdvancedViewController1 : UIViewController {
UIWindow *window;
AdvancedView1 *advancedView1;
UIImageView * option1; 
}
@property (retain) IBOutlet AdvancedView1 *advancedView1;
@property (retain) IBOutlet UIImageView *option1;
@end

在IB中，我已将IBOutlet与AdvancedView1链接到UIView，并将选项1链接到我希望能够移动的UIImageView。

AdvancedViewController.m

#import "AdvancedViewController1.h"
#import "AdvancedView1.h"
@implementation AdvancedViewController1
@synthesize advancedView1;
@synthesize option1

- (void)viewDidLoad { 
UIGestureRecognizer *pangr = [[UIPanGestureRecognizer alloc]       initWithTarget:self.advancedView1 action:@selector(pan:)];
pangr.delegate = self;
[self.advancedView1 addGestureRecognizer:pangr];
[pangr release];      
[super viewDidLoad];
}

AdvancedView1.h

#import <UIKit/UIKit.h>
#import "AdvancedViewController1.h"
@class AdvancedView1;
@interface AdvancedView1 : UIView{
CGPoint* origin;
}
@property (nonatomic)  CGPoint* origin;
@end

AdvancedView1.m
#import "AdvancedView1.h"
#import "AdvancedViewController1.h"
@implementation AdvancedView1;
@synthesize origin;

- (void)pan:(UIPanGestureRecognizer *) gesture
{
if ((gesture.state == UIGestureRecognizerStateChanged) ||
(gesture.state == UIGestureRecognizerStateEnded)) {

CGPoint translation = [gesture translationInView:self];
gesture.origin = CGPointMake(gesture.origin.x+translation.x,        gesture.origin.y+translation.y);
[gesture setTranslation:CGPointZero inView:self];
}

Answer 1

你必须在你的pan：selector中实际设置UIView的位置。而且由于您在AdvancedView类中而不是在其外部执行此操作，因此必须获取视图的父视图（[self superview]），因为更新位置是相对于父（包含）视图。试试这个：

- (void)pan:(UIPanGestureRecognizer *)gesture
{
  if ((gesture.state == UIGestureRecognizerStateChanged) ||
      (gesture.state == UIGestureRecognizerStateEnded)) {

    CGPoint location = [gesture locationInView:[self superview]];

    [self setCenter:location];
  }
}

请注意，您需要确保子类视图允许用户交互或手势识别器不起作用。在初始化视图时，只需使用[self setUserInteractionEnabled:YES]启用它。

无法使用UIPanGestureRecognizer移动UIImageView

1 个答案: