我的要求是：
>需要从服务器URL& ;;在imageview中显示图像保存以供离线使用.
>但可能有可能更新相同的URL图像.
我试过EGOImageview,AsyncImageview,FXImageview,Haneke thsese我试过的所有课程.
我的第一部分要求已经实现.但不是第二次..如果第一次显示“xxxxx”链接图像….如果在同一链接图像上升,app只显示旧图像…
解决方法
您可以使用以下完全满足您要求的课程
DImageView.h
#import <UIKit/UIKit.h> @interface DImageView : UIImageView @property (nonatomic,strong) UIActivityIndicatorView *activityView; - (void)processImageDataWithURLString:(NSString *)urlString; + (UIImage *)getSavedImage :(NSString *)fileName; + (void)saveImageWithFolderName:(NSString *)folderName AndFileName:(NSString *)fileName AndImage:(NSData *) imageData;
DImageView.m
#import "DImageView.h"
#define IMAGES_FOLDER_NAME @"DImages"
@implementation DImageView
#pragma mark - App Life Cycle
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self)
{
}
return self;
}
- (void)dealloc
{
self.activityView = nil;
[super dealloc];
}
- (id)initWithCoder:(NSCoder *)aDecoder
{
self = [super initWithCoder:aDecoder];
if (self)
{
[self initWithFrame:[self frame]];
}
return self;
}
#pragma mark - Download images
- (void)processImageDataWithURLString:(NSString *)urlString //andBlock:(void (^)(UIImage * img))processImage
{
@autoreleasepool
{
UIImage * saveImg = [DImageView getSavedImage:urlString];
if (saveImg)
{
dispatch_queue_t callerQueue = dispatch_get_main_queue();
dispatch_async(callerQueue,^{
@autoreleasepool
{
[self setImage:saveImg];
}
});
}
else
{
[self showActivityIndicator];
NSURL *url = [NSURL URLWithString:[urlString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
dispatch_queue_t callerQueue = dispatch_get_main_queue();
dispatch_queue_t downloadQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH,0);
__block NSError* error = nil;
dispatch_async(downloadQueue,^{
NSData * imageData = [[[NSData dataWithContentsOfURL:url options:NSDataReadingUncached error:&error] retain] autorelease];
if (error)
{
NSLog(@"DImg Error %@",[error debugDescription]);
}
else
{
dispatch_async(callerQueue,^{
@autoreleasepool
{
UIImage *image = [UIImage imageWithData:imageData];
[self setImage:image];
[self hideActivityIndicator];
/* Below code is to save image*/
[DImageView saveImageWithFolderName:IMAGES_FOLDER_NAME AndFileName:urlString AndImage:imageData];
}
});
}
});
dispatch_release(downloadQueue);
}
}
}
#pragma mark - File Save methods
+ (void)saveImageWithFolderName:(NSString *)folderName AndFileName:(NSString *)fileName AndImage:(NSData *) imageData
{
@autoreleasepool
{
NSFileManager *fileManger = [NSFileManager defaultManager] ;
NSString *directoryPath = [NSString stringWithFormat:@"%@/%@",[DImageView applicationDocumentsDirectory],folderName] ;
if (![fileManger fileExistsAtPath:directoryPath])
{
NSError *error = nil;
[fileManger createDirectoryAtPath:directoryPath withIntermediateDirectories:YES attributes:nil error:&error];
}
fileName = [DImageView fileNameValidate:fileName];
NSString *filePath = [NSString stringWithFormat:@"%@/%@",directoryPath,fileName] ;
BOOL isSaved = [imageData writeToFile:filePath atomically:YES];
if (!isSaved)
{
NSLog(@" ** Img Not Saved");
}
}
}
+ (NSString *)applicationDocumentsDirectory
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
NSString *basePath = ([paths count] > 0) ? [paths objectAtIndex:0] : nil;
return basePath;
}
+ (UIImage *)getSavedImage :(NSString *)fileName
{
NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
fileName = [DImageView fileNameValidate:fileName];
NSFileManager * fileManger = [NSFileManager defaultManager] ;
NSString * directoryPath = [NSString stringWithFormat:@"%@/%@",[DImageView applicationDocumentsDirectory],IMAGES_FOLDER_NAME] ;
NSString * filePath = [NSString stringWithFormat:@"%@/%@",fileName] ;
if ([fileManger fileExistsAtPath:directoryPath])
{
UIImage *image = [UIImage imageWithContentsOfFile:filePath] ;
if (image)
{
return image;
}
else
{
NSLog(@"** Img Not Found **");
return nil;
}
}
[pool release];
return nil;
}
+ (NSString*) fileNameValidate : (NSString*) name
{
name = [name stringByReplacingOccurrencesOfString:@"://" withString:@"##"];
name = [name stringByReplacingOccurrencesOfString:@"/" withString:@"#"];
name = [name stringByReplacingOccurrencesOfString:@"%20" withString:@""];
return name;
}
#pragma mark - Activity Methods
- (void) showActivityIndicator
{
self.activityView = [[UIActivityIndicatorView alloc]initWithFrame:CGRectMake(0,self.frame.size.width,self.frame.size.height)];
self.activityView.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleBottomMargin;
self.activityView.hidesWhenStopped = TRUE;
self.activityView.backgroundColor = [UIColor clearColor];
self.activityView.activityIndicatorViewStyle = UIActivityIndicatorViewStyleGray;
[self addSubview:self.activityView];
[self.activityView startAnimating];
}
- (void) hideActivityIndicator
{
CAAnimation *animation = [NSClassFromString(@"CATransition") animation];
[animation setValue:@"kCATransitionFade" forKey:@"type"];
animation.duration = 0.4;;
[self.layer addAnimation:animation forKey:nil];
[self.activityView stopAnimating];
[self.activityView removeFromSuperview];
for (UIView * view in self.subviews)
{
if([view isKindOfClass:[UIActivityIndicatorView class]])
[view removeFromSuperview];
}
}
这堂课会做什么？
它将从服务器下载图像并将其保存到应用程序文档目录,如果可用,则从本地获取.
怎么用？
在你的nib文件中为UIImageView设置DImageView类.
然后,您只需在.m文件中使用它,如下所示.
[imgViewName processImageDataWithURLString:imageURl];
