ios - 实现 UIGestureRecognizerDelegate

Question

我试图从下面的文章中同时进行平移和捏合，但我认为委托(delegate)没有正确连接，因为我看不到任何效果。现在我有一个平移和一个捏合手势识别器，它们都可以工作。我将 IBOutlets 制作到我的 viewcontroller，并且在我的 viewController 初始值设定项中有:

编辑

这里分别是头文件和实现文件。

标题:

#import <UIKit/UIKit.h>
#import <OpenGLES/EAGL.h>
#import <OpenGLES/ES1/gl.h>
#import <OpenGLES/ES1/glext.h>

@class GLView;
@interface GLViewController : UIViewController  <UIGestureRecognizerDelegate>

@property (strong, nonatomic) IBOutlet UIPinchGestureRecognizer *pinchRecognizer;
@property (strong, nonatomic) IBOutlet UIPanGestureRecognizer *panRecognizer;

- (IBAction)handlePinch:(UIPinchGestureRecognizer *)recognizer;
- (IBAction)handlePan:(UIPanGestureRecognizer *)recognizer;
- (void)drawView:(GLView*)view;
- (void)setupView:(GLView*)view;

@property (retain, nonatomic) IBOutlet UILabel *zoomFactorLabel;
@property (retain, nonatomic) IBOutlet UILabel *xPosLabel;
@property (retain, nonatomic) IBOutlet UILabel *yPosLabel;

@end

    panRecognizer.minimumNumberOfTouches = 1;
    panRecognizer.delegate = self; // Very important
    pinchRecognizer.delegate = self; // Very important

实现:

#import "GLViewController.h"
#import "GLView.h"
#import "OpenGLCommon.h"
#import "ConstantsAndMacros.h"
#import "TileManager.h"
#import <CoreGraphics/CoreGraphics.h>

@implementation GLViewController
@synthesize pinchRecognizer;
@synthesize panRecognizer;

@synthesize zoomFactorLabel;
@synthesize xPosLabel;
@synthesize yPosLabel;
TileManager* tileManager;
CGPoint currentPosition;
CGPoint start;
CGFloat temp = 0;
CGFloat x=0;
CGFloat y=0;
CGFloat mLastScale=1;
CGFloat mCurrentScale=1;
CGPoint translation;
- (id) init {
    self = [super init];
    if (self != nil) {
        printf("GLViewController initialized.");
        tileManager=[[TileManager alloc] init];
        currentPosition = CGPointMake(0, 0);
    }
    return self;
}
CGFloat scale=1;
CGPoint position;
CGPoint mid;


#pragma mark - UIGestureRecognizerDelegate

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizershouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
    NSLog(@"delegate called");
   
          // If you have multiple gesture recognizers in this delegate, you can filter them by comparing the gestureRecognizer parameter to your saved objects
    return YES; // Also, very important.
}

- (IBAction)handlePinch:(UIPinchGestureRecognizer *)recognizer {
    scale=scale*recognizer.scale;
    mCurrentScale += [recognizer scale] - mLastScale;
    mLastScale = [recognizer scale];
    if (recognizer.state == UIGestureRecognizerStateBegan)
    {
        //get midpoint
        CGPoint zero=[recognizer locationOfTouch:0 inView:self.view];
        CGPoint one=[recognizer locationOfTouch:1 inView:self.view];
        float x=zero.x+one.x;
        float y=zero.y+one.y;
        mid.x=x/2;
        mid.y=y/2;
    }
    else if (recognizer.state == UIGestureRecognizerStateEnded)
    {
        mLastScale = 1.0;
    }    
    
NSString *xPosString = [NSString stringWithFormat:@"%.2f",mid.x];
    NSString *yPosString = [NSString stringWithFormat:@"%.2f",mid.y];
    xPosLabel.text=xPosString;
    yPosLabel.text=yPosString;
}

- (IBAction)handlePan:(UIPanGestureRecognizer* )recognizer {    
    [recognizer setMaximumNumberOfTouches:1];
    translation= [recognizer translationInView:self.view];
    NSString *xPosString = [NSString stringWithFormat:@"%.2f",currentPosition.x];
    NSString *yPosString = [NSString stringWithFormat:@"%.2f",currentPosition.y];
    xPosLabel.text=xPosString;
    yPosLabel.text=yPosString;
    currentPosition.x=currentPosition.x+translation.x;
    currentPosition.y=currentPosition.y+translation.y;
    [recognizer setTranslation:CGPointMake(0, 0) inView:self.view];
    }


- (void)drawView:(GLView*)view 
{
    glClear(GL_COLOR_BUFFER_BIT);
    glLoadIdentity();
    glTranslatef(mid.x, -mid.y, 0);
    glScalef(mCurrentScale,mCurrentScale, 0);
    glTranslatef(-mid.x, mid.y, 0);
    glTranslatef(currentPosition.x,currentPosition.y*-1,0); 
    [tileManager drawView:view];
   //draw calls
}
-(void)setupView:(GLView*)view
{
    CGRect rect = view.bounds;
    glViewport(0, 0,rect.size.width,rect.size.height);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity(); 
    glOrthof(0,(rect.size.width),-(rect.size.height),0, -1, 1 ) ;  
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();    
    
    glClearColor(0,1,1, 1);
    // Enable Smooth Shading, default not really needed.
    glShadeModel(GL_SMOOTH);
    // Depth buffer setup.
    glClearDepthf(1.0f);
    
    
    //enable textures.
    glEnable(GL_TEXTURE_2D);
    glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_FASTEST);
    glEnable(GL_BLEND); 
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    
    [tileManager setupView:view];    
}

 - (void)viewDidLoad
 {
 [super viewDidLoad];
     panRecognizer.delegate=self;
     pinchRecognizer.delegate=self;
NSLog(@"pan recognizer delegate [%@]", [panRecognizer.delegate description]);
 }
 
- (void)viewDidUnload {
    [self setPinchRecognizer:nil];
    [self setPanRecognizer:nil];
    [super viewDidUnload];
}
@end

NSLog 位于委托(delegate)方法的主体中，但从未被执行。感谢您的帮助。

article

Answer 1

如果 View Controller 是从界面构建器加载的，那么初始化程序就是设置这些东西的错误位置。在 -viewDidLoad 中执行。