如何從服務器檢索一組圖像並將其存儲在iOS中的文檔目錄中？

Question

我想從服務器中檢索包含10個圖像的文件夾，然後將該文件夾存儲在我的文檔目錄中。我做了一些代碼，但是當我運行它時，我正在獲取圖像url，而不是圖像本身。誰能幫我嗎？

我的代碼：

-(void)viewWillAppear:(BOOL)animated 
{ 

NSMutableData *receivingData = [[NSMutableData alloc] init]; 
NSURL *url = [NSURL URLWithString:@"http://Someurl.filesCount.php"]; 
NSURLRequest *req = [NSURLRequest requestWithURL:url]; 


    NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:req delegate:self startImmediately:YES]; 

} 

-(void) connection:(NSURLConnection *)connection didReceiveData:(NSData *)data 
{ 

[receivingData appendData:data]; 
} 
-(void) connectionDidFinishLoading:(NSURLConnection *)connection 
{ 
NSError *error = nil; 

{ 
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
NSString *path = [paths objectAtIndex:0]; 
printf("\n the path is :%s",[path UTF8String]); 


NSString *zipPath = [path stringByAppendingPathComponent:@"filesCount.php"]; 

[receivingData writeToFile:zipPath options:0 error:&error]; 



     NSString *documentsDirectoryPath = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"filesCount"]; 
     NSLog(@"the path %@",documentsDirectoryPath); 



} 

Answer 1

我在我以前的項目中做過這個功能。您需要傳遞imageView和serverUrl，然後在您的imageView中自動顯示圖像並將圖像保存到臨時目錄，當您想再次獲取相同圖像時，則下一次從磁盤獲取圖像。

+(void)downloadingServerImageFromUrl:(UIImageView*)imgView AndUrl:(NSString*)strUrl{ 

NSFileManager *fileManager =[NSFileManager defaultManager]; 

NSString* theFileName = [NSString stringWithFormat:@"%@.png",[[strUrl lastPathComponent] stringByDeletingPathExtension]]; 
NSString *fileName = [NSHomeDirectory() stringByAppendingPathComponent:[NSString stringWithFormat:@"tmp/%@",theFileName]]; 


imgView.backgroundColor = [UIColor darkGrayColor]; 
UIActivityIndicatorView *actView = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite]; 
[imgView addSubview:actView]; 
[actView startAnimating]; 
CGSize boundsSize = imgView.bounds.size; 
CGRect frameToCenter = actView.frame; 
// center horizontally 
if (frameToCenter.size.width < boundsSize.width) 
    frameToCenter.origin.x = (boundsSize.width - frameToCenter.size.width)/2; 
else 
    frameToCenter.origin.x = 0; 

// center vertically 
if (frameToCenter.size.height < boundsSize.height) 
    frameToCenter.origin.y = (boundsSize.height - frameToCenter.size.height)/2; 
else 
    frameToCenter.origin.y = 0; 

actView.frame = frameToCenter; 


dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0); 
dispatch_async(queue, ^{ 

    NSData *dataFromFile = nil; 
    NSData *dataFromUrl = nil; 

    dataFromFile = [fileManager contentsAtPath:fileName]; 
    if(dataFromFile==nil){ 
     dataFromUrl=[[[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:strUrl]] autorelease]; 
    } 

    dispatch_sync(dispatch_get_main_queue(), ^{ 

     if(dataFromFile!=nil){ 
      imgView.image = [UIImage imageWithData:dataFromFile]; 
     }else if(dataFromUrl!=nil){ 
      imgView.image = [UIImage imageWithData:dataFromUrl]; 
      // NSString *fileName = [NSHomeDirectory() stringByAppendingPathComponent:[NSString stringWithFormat:@"tmp/%@",theFileName]]; 

      BOOL filecreationSuccess = [fileManager createFileAtPath:fileName contents:dataFromUrl attributes:nil]; 
      if(filecreationSuccess == NO){ 
       NSLog(@"Failed to create the html file"); 
      } 

     }else{ 
      imgView.image = [UIImage imageNamed:@"NO_Image.png"]; 
      imgView.tag = 105; 
     } 
     [actView removeFromSuperview]; 
     [actView release]; 
    }); 
}); 

} 

Answer 2

如果你會顯示來自服務器加載UI上的圖像，然後

嘗試SDWebImageView，可以用的UIButton或UIImageView的，很容易和高效使用。

例如，

[yourImageView setImageWithURL:[NSURL URLWithString:@"http://www.domain.com/path/to/image.jpg"] 
       placeholderImage:[UIImage imageNamed:@"placeholder.png"]]; 

讀how to use it?

好了，現在對多張圖片，你可能需要運行一個循環，如果你對所有圖片的共同基礎URL（在服務器上）如http://yoururl/server/pictures/1.png將被2.png 3.png ... n.png替換，或者您獲得不同url的圖片需要傳遞該url，您可以將其加載到imageview對象中，並稍後將其保存到文檔目錄中（請記住，默認爲您執行此項工作爲SDWebImageView）。你也可以關掉它。

P.S.它將加載一次圖像並存儲到本地（緩存）中，下次您傳遞相同的圖像url時，它不會從服務器加載並直接從本地加載圖像。

Answer 3

請嘗試使用此代碼。

NSURL* url = [NSURL URLWithString:@"http://imageAddress.com"]; 
NSURLRequest* request = [NSURLRequest requestWithURL:url]; 


[NSURLConnection sendAsynchronousRequest:request 
queue:[NSOperationQueue mainQueue] 
completionHandler:^(NSURLResponse * response, 
    NSData * data, 
    NSError * error) { 
if (!error){ 
     // do whatever you want with directory or store images. 
    NSImage* image = [[NSImage alloc] initWithData:data]; 

} 

}]; 

Answer 4

使用此代碼使用URL下載圖像並存儲在文檔目錄中。迭代用於下載和存儲的一組圖像的邏輯。

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
     NSString *imageURL = @"http://sampleUrl"; 
     NSString *documentsDirectory = [paths objectAtIndex:0]; // Get documents folder 
     UIImage *image = [[UIImage alloc] initWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:imageURL]]]; 

     NSString *imagePath = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"Image1.png"]]; 
     if(image != NULL) 
     { 
      //Store the image in Document 
      NSData *imageData = UIImagePNGRepresentation(image); 
      [imageData writeToFile: imagePath atomically:YES]; 
     }