我想实现一个启用分页的 UIScrollView,我可以只浏览一些图像。这就是我现在想做的一切。
到目前为止,我已经在界面生成器中完成了此操作:有人可以帮忙吗?
剩下的我不知道该怎么做。有人可以帮我解决这个问题吗?我不需要任何缩放功能。我不想在滚动视图中预览上一张或下一张图像,我只想要一个简单的启用分页的滚动视图,允许用户轻拂图像。
感谢所有帮助。 如果您能一步一步告诉我如何实现这一目标,我将不胜感激。谢谢你。
我查看了代码示例,发现它们过于复杂。我看过几个并且更喜欢从头开始的教程。谢谢你
也许你想看看我的视图控制器的示例实现,它确实做到了这一点。我写这个东西是为了回答这个问题。
也许这对你来说太复杂了,但它不会变得更容易。
这只是基本版本,它在启动时将所有图像加载到内存中。这在实际应用中是行不通的。所以你必须实现一些 UIScrollView-Delegate 函数。复杂性就从这里开始......
// ImageViewController.h
//
// Created by Matthias Bauch on 12.10.10.
// Copyright 2010 Matthias Bauch. All rights reserved.
//
#import <UIKit/UIKit.h>
#warning this is just a quick hack, you should not use this if you dont understand this. There might be leaks, bugs and a lot of whatever.
@interface ImageViewController : UIViewController {
NSString *imagePath;
}
@property (nonatomic, copy) NSString *imagePath;
- (id)initWithImageDirectory:(NSString*)imgPath;
@end
//
// ImageViewController.m
//
// Created by Matthias Bauch on 12.10.10.
// Copyright 2010 Matthias Bauch. All rights reserved.
//
#import "ImageViewController.h"
@implementation ImageViewController
@synthesize imagePath;
- (id)initWithImageDirectory:(NSString*)imgPath {
if (self = [super init]) {
imagePath = [imgPath copy];
}
return self;
}
- (UIView *)viewFullOfImagesAtPath:(NSString *)path withSize:(CGSize)size {
NSError *error = nil;
NSArray *filenames = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:path error:&error];
if (!filenames) {
NSLog(@"Error accessing files: %@ [%@]", [error localizedDescription], error);
return nil;
}
UIView *aView = [[UIView alloc] init];
CGFloat xOffset = 0;
for (NSString *filename in filenames) {
NSString *fullPath = [path stringByAppendingPathComponent:filename];
UIImage *image = [[[UIImage alloc] initWithContentsOfFile:fullPath] autorelease];
if (!image)
continue;
CGRect frameRect = CGRectMake(xOffset, 0, size.width, size.height);
UIImageView *imageView = [[[UIImageView alloc] initWithFrame:frameRect] autorelease];
[imageView setImage:image];
imageView.contentMode = UIViewContentModeScaleAspectFit;
[aView addSubview:imageView];
xOffset += size.width;
}
aView.frame = CGRectMake(0, 0, xOffset, size.height);
return [aView autorelease];
}
- (void)viewDidLoad {
[super viewDidLoad];
UIScrollView *scrollView = [[[UIScrollView alloc] initWithFrame:self.view.bounds] autorelease];
scrollView.pagingEnabled = YES;
UIView *contentView = [self viewFullOfImagesAtPath:imagePath withSize:CGSizeMake(self.view.bounds.size.width, self.view.bounds.size.height)];
NSLog(@"%f %f %f %f", contentView.frame.origin.x, contentView.frame.origin.y, contentView.frame.size.width, contentView.frame.size.height);
[scrollView addSubview:contentView];
scrollView.contentSize = CGSizeMake(CGRectGetWidth(contentView.frame), CGRectGetHeight(contentView.frame));
[self.view addSubview:scrollView];
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
// Overriden to allow any orientation.
return YES;
}
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
- (void)viewDidUnload {
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)dealloc {
[imagePath release];
[super dealloc];
}
@end
听起来您只需将内容添加为 UIScrollView 的子视图并添加手势识别器。
将图像加载到 UIImageView 中。添加 UIImageView 作为 UIScrollView 的子视图。
// do this in init or loadView or viewDidLoad, wherever is most appropriate
// imageView is a retained property
self.imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"image1.png"];
[scrollView addSubview:imageView];
将 UISwipeGestureRecognizer 添加到 UIScrollView。
// probably after the code above
UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipe:);
[scrollView addGestureRecognizer:swipe];
[swipe release];
在 UISwipeGestureRecognizer 处理程序上,更改 UIImageView 中加载的图像。
- (void)handleSwipe:(UIGestureRecognizer *)swipe {
// do what you need to determine the next image
imageView.image = [UIImage imageNamed:<your replacement image here>];
}