從網路下載圖片，儲存，並用UIImageView從儲存中顯示，

從網路下載圖片，儲存，並用UIImageView從儲存中顯示，

 

代碼：

 

- (void)viewDidLoad{    [super viewDidLoad];    // Do any additional setup after loading the view.            UIImageView *img=[[UIImageView alloc]initWithFrame:CGRectMake(50, 100, 200, 200)];    img.backgroundColor=[UIColor redColor];    [self.view addSubview:img];            //從網路下載圖片，儲存，並用 UIImageView 從儲存中顯示    NSString * documentsDirectoryPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];    NSLog(@"儲存路徑:%@",documentsDirectoryPath);            //Get Image From URL    UIImage * imageFromURL = [self getImageFromURL:@"http://file.duteba.com/phone/2009/04/5/ftGxL8kcUL.jpg"];            //Save Image to Directory    [self saveImage:imageFromURL withFileName:@"MyImage" ofType:@"jpg" inDirectory:documentsDirectoryPath];            //Load Image From Directory    UIImage * imageFromWeb = [self loadImage:@"MyImage" ofType:@"jpg" inDirectory:documentsDirectoryPath];    [img setImage:imageFromWeb];            //取得目錄下所有檔案名稱    NSArray *file = [[[NSFileManager alloc] init] subpathsAtPath:documentsDirectoryPath];    NSLog(@"%d",[file count]);    NSLog(@"%@",file);    }//從網路下載圖片-(UIImage *) getImageFromURL:(NSString *)fileURL {    NSLog(@"執行圖片下載函數");    UIImage * result;        NSData * data = [NSData dataWithContentsOfURL:[NSURL URLWithString:fileURL]];    result = [UIImage imageWithData:data];        return result;}//將所下載的圖片儲存到本地-(void) saveImage:(UIImage *)image withFileName:(NSString *)imageName ofType:(NSString *)extension inDirectory:(NSString *)directoryPath {    if ([[extension lowercaseString] isEqualToString:@"png"]) {        [UIImagePNGRepresentation(image) writeToFile:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", imageName, @"png"]] options:NSAtomicWrite error:nil];    } else if ([[extension lowercaseString] isEqualToString:@"jpg"] || [[extension lowercaseString] isEqualToString:@"jpeg"]) {        [UIImageJPEGRepresentation(image, 1.0) writeToFile:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", imageName, @"jpg"]] options:NSAtomicWrite error:nil];    } else {        //ALog(@"Image Save Failed\nExtension: (%@) is not recognized, use (PNG/JPG)", extension);        NSLog(@"檔案尾碼不認識");    }}//讀取本地儲存的圖片-(UIImage *) loadImage:(NSString *)fileName ofType:(NSString *)extension inDirectory:(NSString *)directoryPath {    UIImage * result = [UIImage imageWithContentsOfFile:[NSString stringWithFormat:@"%@/%@.%@", directoryPath, fileName, extension]];        return result;}