//
// ImageViewerController.h
// ImageViewer
//
// Created by wangsheng on 12-8-30.
// Copyright (c) 2012年 wangsheng. All rights reserved.
//
#import
@interface ImageViewerController : UIViewController <UIScrollViewDelegate>
@property (strong, nonatomic) IBOutlet UIScrollView *sv;
@property (strong, nonatomic) IBOutlet UIImageView *iv;
@property (strong, nonatomic) IBOutlet UIView *loadingView;
- (void)loadImage:(NSString *)imageURL;
@end
//
// ImageViewerController.m
// ImageViewer
//
// Created by wangsheng on 12-8-30.
// Copyright (c) 2012年 wangsheng. All rights reserved.
//
#import "ImageViewerController.h"
@interface ImageViewerController ()
@end
@implementation ImageViewerController
@synthesize sv;
@synthesize iv;
@synthesize loadingView;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
self.view.backgroundColor = [UIColor blackColor];
[self.view addSubview:loadingView];
self.sv.delegate = self;
[self loadImage:@"http://b218.photo.store.qq.com/psb?/V14b2MUB2EAmtl/kbZCrL7A9u.GV4SWP.1EHsReqMEspo1uv5aKcDn*.8c!/b/Yas484HnBAAAYjY684GiBAAA&bo=fAIgA3s!"];
}
// 加载图片
- (void)loadImage:(NSString *)imageURL
{
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:imageURL]];
[NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue currentQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *error){
if([data length] > 0 && error==nil){
NSString *result = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSRange range = [result rangeOfString:@"404 Not Found"];
if(range.location != 0){
[self showLoadFailedAlert];
[UIView animateWithDuration:0.3 delay:0.3 options:UIViewAnimationCurveLinear animations:^ {
self.loadingView.alpha = 0;
} completion:^(BOOL finished){
[self.loadingView setHidden:YES];
}];
return;
}
UIImage *image = [UIImage imageWithData:data];
// 重置UIImageView的Frame，让图片居中显示
CGFloat origin_x = abs(sv.frame.size.width - image.size.width)/2.0;
CGFloat origin_y = abs(sv.frame.size.height - image.size.height)/2.0;
self.iv.frame = CGRectMake(origin_x, origin_y, sv.frame.size.width, sv.frame.size.width*image.size.height/image.size.width);
[self.iv setImage:image];
CGSize maxSize = sv.frame.size;
CGFloat widthRatio = maxSize.width/image.size.width;
CGFloat heightRatio = maxSize.height/image.size.height;
CGFloat initialZoom = (widthRatio > heightRatio) ? heightRatio : widthRatio;
/*
** 设置UIScrollView的最大和最小放大级别（注意如果MinimumZoomScale == MaximumZoomScale，
** 那么UIScrllView就缩放不了了
*/
[sv setMinimumZoomScale:initialZoom];
[sv setMaximumZoomScale:5];
// 设置UIScrollView初始化缩放级别
[sv setZoomScale:initialZoom];
// 动态隐藏加载界面，从而显示图片
[UIView animateWithDuration:0.3 delay:0.3 options:UIViewAnimationCurveLinear animations:^{
self.loadingView.alpha = 0;
} completion:^(BOOL finished){
[self.loadingView setHidden:YES];
}];
}else{
[self showLoadFailedAlert];
}
}];
}
// 设置UIScrollView中要缩放的视图
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return self.iv;
}
// 让UIImageView在UIScrollView缩放后居中显示
- (void)scrollViewDidZoom:(UIScrollView *)scrollView
{
CGFloat offsetX = (scrollView.bounds.size.width > scrollView.contentSize.width)?
(scrollView.bounds.size.width - scrollView.contentSize.width) * 0.5 : 0.0;
CGFloat offsetY = (scrollView.bounds.size.height > scrollView.contentSize.height)?
(scrollView.bounds.size.height - scrollView.contentSize.height) * 0.5 : 0.0;
iv.center = CGPointMake(scrollView.contentSize.width * 0.5 + offsetX,
scrollView.contentSize.height * 0.5 + offsetY);
}
// 显示加载失败的提示对话框
- (void)showLoadFailedAlert
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"提示"
message:@"加载图片失败"
delegate:nil
cancelButtonTitle:@"确定"
otherButtonTitles:nil];
[alert show];
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
@end