我在带有Accelerometer的Bounce类中有子类UIView类。 此Bounce类显示图像并将其移动到屏幕上。移动iPhone设备时，此图像会在屏幕上弹跳。
当我创建多个实例时，只有最后一个实例正常工作：
// in the MainViewController.m
Bounce *heart[100];
for(int i = 0; i < 10; i++) {
rx = (arc4random() % 300) + 10;
ry = (arc4random() % 300) + 10;
NSLog(@"random %d %d", rx, ry);
heart[i] = [[Bounce alloc] initWithPNG:@"Heart.png"
position:CGPointMake(rx, ry) size:CGSizeMake(64, 64)];
heart[i].velocity = CGPointMake(1.0, 1.0);
[self.view addSubview: heart[i]];
}
这是弹跳类：
//
// Bounce.h
// iMakeLove
//
// Created by Giovambattista Fazioli on 06/11/09.
// Copyright 2009 Saidmade srl. All rights reserved.
//
#import <UIKit/UIKit.h>
@interface Bounce : UIView <UIAccelerometerDelegate> {
CGPoint position;
CGSize size;
CGPoint velocity;
NSTimer *objTimer;
NSString *pngName;
CGFloat bounce;
CGFloat gravity;
CGPoint acceleratedGravity;
CGPoint lastTouch;
CGPoint currentTouch;
BOOL dragging;
UIAccelerometer *accelerometer;
}
@property CGPoint position;
@property CGSize size;
@property CGPoint velocity;
@property(nonatomic,retain)NSString *pngName;
@property(nonatomic,retain)NSTimer *objTimer;
@property CGFloat bounce;
@property CGFloat gravity;
@property CGPoint acceleratedGravity;
@property CGPoint lastTouch;
@property CGPoint currentTouch;
@property BOOL dragging;
- (id)initWithPNG:(NSString*)imageName position:(CGPoint)p size:(CGSize)s;
- (void)update;
- (void)onTimer;
- (void)startPrevent;
@end
实现：
//
// Bounce.m
// iMakeLove
//
// Created by Giovambattista Fazioli on 06/11/09.
// Copyright 2009 Saidmade srl. All rights reserved.
//
#import "Bounce.h"
@implementation Bounce
@synthesize position, size;
@synthesize objTimer;
@synthesize velocity;
@synthesize pngName;
@synthesize bounce;
@synthesize gravity, acceleratedGravity;
@synthesize lastTouch, currentTouch;
@synthesize dragging;
- (id)initWithPNG:(NSString*)imageName position:(CGPoint)p size:(CGSize)s {
if (self = [super initWithFrame:CGRectMake(p.x, p.y, s.width, s.height)]) {
[self setPngName:imageName];
[self setPosition:p];
[self setSize:s];
[self setBackgroundColor:[UIColor clearColor]];
// Set default gravity and bounce
[self setBounce:-0.9f];
[self setGravity:0.5f];
[self setAcceleratedGravity:CGPointMake(0.0, gravity)];
[self setDragging:NO];
UIImageView *prezzie = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, s.width, s.height)];
prezzie.image = [UIImage imageNamed:imageName];
[self addSubview:prezzie];
[prezzie release];
self.accelerometer = [UIAccelerometer sharedAccelerometer];
self.accelerometer.delegate = self;
}
return self;
}
- (void)startPrevent {
if (objTimer == nil) {
objTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 / 30.0 target:self selector:@selector(onTimer) userInfo:nil repeats:YES];
}
}
- (void)update {
[self setNeedsDisplay];
if(dragging) return;
velocity.x += acceleratedGravity.x;
velocity.y += acceleratedGravity.y;
position.x += velocity.x;
position.y += velocity.y;
if(position.x + size.width >= 320.0) {
position.x = 320.0 - size.width;
velocity.x *= bounce;
} else if(position.x <= 0.0) {
velocity.x *= bounce;
}
if(position.y + size.height >= 480.0) {
position.y = 480.0 - size.height;
velocity.y *= bounce;
} else if(position.y <= 0.0) {
velocity.y *= bounce;
}
self.frame = CGRectMake(position.x, position.y, size.width, size.height);
}
- (void)onTimer {
[self update];
}
- (void)drawRect:(CGRect)rect {
// Drawing code
}
/* EVENTS */
- (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration {
acceleratedGravity.x = acceleration.x * gravity;
acceleratedGravity.y = -acceleration.y * gravity;
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
// First, lets check to make sure the timer has been initiated
if (objTimer == nil) {
objTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 / 30.0 target:self selector:@selector(onTimer) userInfo:nil repeats:YES];
}
UITouch *touch = [touches anyObject];
[self setCurrentTouch:[touch locationInView:self]];
CGFloat dx = currentTouch.x - position.x;
CGFloat dy = currentTouch.y - position.y;
CGFloat dist = sqrt(dx * dx + dy * dy);
if(dist < size.width) {
[self setVelocity:CGPointMake(0.0, 0.0)];
[self setDragging:YES];
}
[self setLastTouch:currentTouch];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
[self setCurrentTouch:[touch locationInView:self]];
[self setDragging:YES];
[self setVelocity:CGPointMake(currentTouch.x - lastTouch.x, currentTouch.y - lastTouch.y)];
[self setLastTouch:currentTouch];
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
[self setDragging:NO];
}
- (id)initWithFrame:(CGRect)frame {
if (self = [super initWithFrame:frame]) {
// Initialization code
}
return self;
}
- (void)dealloc {
[super dealloc];
}
@end
你能帮助我吗？
答案 0 :(得分：2)
那是因为self.accelerometer.delegate = self;正在更改sharedAccelerometer的委托，只有最后一项作业才有效。
答案 1 :(得分：0)
我相信只有最前面的视图才能获得加速度计信息。您可能希望将加速度计消息发送到您的viewcontroller。
答案 2 :(得分：0)
我可以在这做什么（这可能不是长期最好的事情，但会解决眼前的问题）是这样的：
我将加速重力作为所有Bounce实例共享的静态变量。这对我来说是因为在现实世界中（我们正在模拟的那个）加速重力对于所有弹跳都是相同的。 （我还将Bounce重命名为BouncingView之类的东西）。我通过几个类方法访问该变量。此外，我将加速度计共享，并具有其委托方法，类方法。把这些东西放在你的课堂上它应该可以工作:(我会测试它，但我的开发机器在Apple Store中得到修复。）另外，你发布的示例代码中有几个语法错误。
static CGCGPoint acceleratedGravity;
static UIAccelerometer *accelerometer;
-(void) init {
/* Everything Else */
self.accelerometer = [UIAccelerometer sharedAccelerometer];
self.accelerometer.delegate = self;
/*Everything Else */
}
+(CGPoint) acceleratedGravity {
return acceleratedGravity;
}
+(void) setAcceleratedGravity:(CGPoint) _acceleratedGravity {
acceleratedGravity = _acceleratedGravity;
}
+ (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration {
acceleratedGravity.x = acceleration.x * gravity;
acceleratedGravity.y = -acceleration.y * gravity;
}