I am using DBChooser in my application to import images from dropbox, I am getting image url like & to dasplay the image in UIImageView i have following code
UIImageView *imageView=[[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 500, 500)];
imageView.image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:#"https://www.dropbox.com/s/7qey2let40eb9je/PRELIMINARY_FORM_2.jpg"]]];
[self.view addSubview:imageView];
but the image is not showing in application. please help me how to display the dropbox image in UIImageView, is it issue of https OR what .
See this reference: https://cantonbecker.com/etcetera/2014/how-to-directly-link-or-embed-dropbox-images/
Short answer: append raw=1 as querystring value to your image url
Let's try:
+ (void) downloadImage : (NSURL*) url withCallBack:(DownloadCallbackBlock)callback
{
NSURLRequest *urlRequest = [NSURLRequest requestWithURL:url];
NSOperationQueue *queue = [[NSOperationQueue alloc] init];
[NSURLConnection sendAsynchronousRequest:urlRequest queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *error)
{
NSHTTPURLResponse *httpresponse = (NSHTTPURLResponse *)response;
if (httpresponse.statusCode == 200)
{
callback(error,data);
}
else
{
//error
}
}];
}
And I use it:
[DownloadManager downloadImage:url withCallBack:^(NSError *error, NSData *data){
if (data)
{
UIImage *image = [[UIImage alloc]initWithData:data];
[_arrImages addObject:image];
dispatch_async(dispatch_get_main_queue(), ^{
[self processAddImage];
});
}
Related
I am trying to learn web service on iOS.
I'm starting of from getting an image from a JSON api link.
I've used the code below but the image is not displaying and I'm getting warning that says
Incompatible pointer types assigning to 'UIImage * _Nullable' from 'NSSting * _Nullable'
My code
NSURL *urlAdPop = [NSURL URLWithString:#"JSON LINK HERE"];
NSURLRequest *request = [NSURLRequest requestWithURL:urlAdPop];
[NSURLConnection sendAsynchronousRequest:request
queue:[NSOperationQueue mainQueue]
completionHandler:^(NSURLResponse *response,
NSData *data, NSError *connectionError)
{
if (data.length > 0 && connectionError == nil)
{
NSDictionary *AdPopUp = [NSJSONSerialization JSONObjectWithData:data
options:0
error:NULL];
popUpBanner.image = [[AdPopUp objectForKey:#"ad_image"] stringValue];
popUpAdURL = [AdPopUp objectForKey:#"ad_link"];
}
}];
popUpBanner.image = [UIImage imageWithData:[NSData dataWithContentsOfURL:popUpAdURL]];
popUpBanner.hidden = NO;
popUpBanner.layer.cornerRadius = 9;
popUpBanner.clipsToBounds = YES;
popUpBanner.userInteractionEnabled = YES;
[self.view addSubview:popUpBanner];
You need to write your code inside block after you get response from webservice.
NSURL *urlAdPop = [NSURL URLWithString:#"JSON LINK HERE"];
NSURLRequest *request = [NSURLRequest requestWithURL:urlAdPop];
[NSURLConnection sendAsynchronousRequest:request
queue:[NSOperationQueue mainQueue]
completionHandler:^(NSURLResponse *response,
NSData *data, NSError *connectionError)
{
if (data.length > 0 && connectionError == nil)
{
NSDictionary *AdPopUp = [NSJSONSerialization JSONObjectWithData:data
options:0
error:NULL];
popUpBanner.image = [[AdPopUp objectForKey:#"ad_image"] stringValue];
popUpAdURL = [AdPopUp objectForKey:#"ad_link"];
UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfURL:popUpAdURL]];
dispatch_async(dispatch_get_main_queue(), ^{ // get main thread to update image
popUpBanner.image= image
popUpBanner.hidden = NO;
popUpBanner.layer.cornerRadius = 9;
popUpBanner.clipsToBounds = YES;
popUpBanner.userInteractionEnabled = YES;
[self.view addSubview:popUpBanner];
});
}
}];
popUpBanner.layer.cornerRadius = 9;
popUpBanner.clipsToBounds = YES;
popUpBanner.userInteractionEnabled = YES;
popUpBanner.hidden = YES;
[self.view addSubview:popUpBanner];
NSString* strURL=#"JSON LINK HERE";
NSString* webStringURL = [strURL stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *urlAdPop = [NSURL URLWithString:webStringURL];
NSURLRequest *request = [NSURLRequest requestWithURL:urlAdPop];
[NSURLConnection sendAsynchronousRequest:request
queue:[NSOperationQueue mainQueue]
completionHandler:^(NSURLResponse *response,
NSData *data, NSError *connectionError)
{
if (data.length > 0 && connectionError == nil)
{
NSDictionary *AdPopUp = [NSJSONSerialization JSONObjectWithData:data
options:0
error:NULL];
popUpAdURL = [AdPopUp objectForKey:#"ad_link"];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
NSData *imgData = [NSData dataWithContentsOfURL:[NSURL URLWithString:[NSString stringWithFormat:#"%#",[AdPopUp objectForKey:#"ad_image"]]]];
if (imgData)
{
UIImage *image = [UIImage imageWithData:imgData];
if (image)
{
dispatch_async(dispatch_get_main_queue(), ^{
popUpBanner.image = image;
popUpBanner.hidden = NO;
});
}
else
{
dispatch_async(dispatch_get_main_queue(), ^{
});
}
}
else
{
dispatch_async(dispatch_get_main_queue(), ^{
});
}
});
}
}];
Perfect way to display image!
Hope It will help you :)
If you need to deal with images comes from web response then you can use SDWebImage library from GitHub.
In its read me page they have also provided the way how you can achieve it.
#import <SDWebImage/UIImageView+WebCache.h>
[self.YourImageView sd_setImageWithURL:[NSURL URLWithString:#"http://yourimagePath/.../"]
placeholderImage:[UIImage imageNamed:#"placeholder.png"]];
Thats it !
Firstly,check if that url available in browser. If yes,check if your app accept HTTP(not HTTPS). You can set app accept like this:
You are adding popUpBanner in view after getting image from server. so you have to initialize it before in viewdidload and need to set it's frame.
Then set image to popUpBanner from completion handler of web service on main thread. And make sure that you have to set image not image name string!
Below line is wrong, it is trying to set string to imageview which is not possible.
popUpBanner.image = [[AdPopUp objectForKey:#"ad_image"] stringValue];
get image from image url provided by service side and use image name that you get in response.
And make sure that you are getting image object using breakpoint.
Hope this will help :)
###require suppurate api to load image.
want to attach the link and image name together as to reach. thus two strings are needed to store each the api and the image name.###
s=[[mutarray objectAtIndex:index]valueForKey:#"image"];
NSString *f=[NSString stringWithFormat:#"http://iroidtech.com/wecare/uploads/news_events/%#",s];
NSURL *g=[[NSURL alloc]initWithString:f];
data=[NSMutableData dataWithContentsOfURL:g];
self.imgvw.image=[UIImage imageWithData:data];
_descrilbl.text=[[mutarray objectAtIndex:index]valueForKey:#"image"];
I have a TableView with customCells, when user press Start button on some cell the loading starts. There are many such cells, so I need to implement this downloading in parallel (asynchronously).
For image downloading and updating the cell in Table view I use next code:
#define myAsyncQueue dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)
I include this method into the async queue, that I supposed should enable parallel downloading of images.
- (void)didClickStartAtIndex:(NSInteger)cellIndex withData:
(CustomTableViewCell*)data
{
dispatch_async(myAsyncQueue, ^{
self.customCell = data;
self.selectedCell = cellIndex;
ObjectForTableCell* tmp =[self.dataDictionary objectForKey:self.names[cellIndex]];
NSURLRequest *urlRequest = [NSURLRequest requestWithURL:[NSURL URLWithString:tmp.imeageURL]
cachePolicy:NSURLRequestReloadIgnoringLocalCacheData
timeoutInterval:60.0];
self.connectionManager = [[NSURLConnection alloc] initWithRequest:urlRequest delegate:self];
});
}
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
self.urlResponse = response;
NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *) response;
NSDictionary *dict = httpResponse.allHeaderFields;
NSString *lengthString = [dict valueForKey:#"Content-Length"];
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
NSNumber *length = [formatter numberFromString:lengthString];
self.totalBytes = length.unsignedIntegerValue;
self.imageData = [[NSMutableData alloc] initWithCapacity:self.totalBytes];
}
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[self.imageData appendData:data];
self.customCell.progressView.progress = ((100.0/self.urlResponse.expectedContentLength)*self.imageData.length)/100;
float per = ((100.0/self.urlResponse.expectedContentLength)*self.imageData.length);
self.customCell.realProgressStatus.text = [NSString stringWithFormat:#"%0.f%%", per];
}
I tried to set this block to queue - main queue - cause its the place where image is already downloaded,
-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
dispatch_async(dispatch_get_main_queue(), ^{
self.customCell.realProgressStatus.text = #"Downloaded";
UIImage *img = [UIImage imageWithData:self.imageData];
self.customCell.image.image = img;
self.customCell.tag = self.selectedCell;
});
[self.savedImages setObject:img forKey:self.customCell.nameOfImage.text];
NSNumber *myNum = [NSNumber numberWithInteger:self.selectedCell];
[self.tagsOfCells addObject:myNum];
}
Without all queues(when I comment it)all works properly - but just 1 downloading at a ones.
But when I tried to implement code with queues as a result it doesn't download anything. I understand that I did smh wrong but I can't define it.
Thanks a lot for any help in advance.
If your looking out for starting it form basics I guess you should start with NSURLSession as NSURLConnection most of implementation had been deprecated and won't be available after iOS 9. For complete reference URL Session Programming Guide and tutorial
Coming back to your question you should do something similar to this took it from tutorial
// 1
NSURLSessionDownloadTask *getImageTask =
[session downloadTaskWithURL:[NSURL URLWithString:imageUrl]
completionHandler:^(NSURL *location,
NSURLResponse *response,
NSError *error) {
// 2
UIImage *downloadedImage =
[UIImage imageWithData:
[NSData dataWithContentsOfURL:location]];
//3
dispatch_async(dispatch_get_main_queue(), ^{
// do stuff with image
_imageWithBlock.image = downloadedImage;
});
}];
// 4
[getImageTask resume];
But my personal recommendation is go for AFNetworking which is best for iOS networking and widely used/tested in iOS app world.
For image download using AFNetworking
[_imageView setImageWithURLRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:#"http://i.imgur.com/fVhhR.png"]]
placeholderImage:nil
success:^(NSURLRequest *request , NSHTTPURLResponse *response , UIImage *image ){
NSLog(#"Loaded successfully: %d", [response statusCode]);
}
failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error){
NSLog(#"failed loading: %#", error);
}
];
EDIT : Async downloading using concurrency
// get main dispact queue
dispatch_queue_t queue = dispatch_get_main_queue();
// adding downloading task in queue using block
dispatch_async(queue, ^{
NSData* imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:imageURL]];
UIImage* image = [[UIImage alloc] initWithData:imageData];
// after download compeletes geting main queue again as there can a possible crash if we assign directly
dispatch_async(dispatch_get_main_queue(), ^{
_imageWithBlock.image = image;
});
});
Use this sample code from Apple to solve your problem of lazy loading.
I Have copied the contents of file from here and created a UIImageView+AFNetworking.h and imported in my implementation file
Now When I Write the following code i get this error but when i remove the block of code then everything works fine.
I want to display image in a custom table cell.The url of image i am grabbing Through JSON
NSURLRequest *imageRequest = [NSURLRequest requestWithURL:[NSURL URLWithString:[dictArray objectForKey:#"image"]]];
[cell.thumbnailImageView setImageWithURLRequest:imageRequest placeholderImage:nil
success:^(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image){
NSLog(#"success");
cell.thumbnailImageView.image = image;
cell.thumbnailImageView.contentMode = UIViewContentModeScaleAspectFit;
cell.thumbnailImageView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
[cell setNeedsLayout];// To update the cell {if not using this, your image is not showing over cell.}
}failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error){
NSLog(#"Failure");}];
Here is the screen shot of the error
It Crashes after loading
Instead of using afnetworking You can just use dispatch method
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0ul);
dispatch_async(queue, ^{
NSString *url = [indexDic objectForKey:#"image"];
NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:url]];
UIImage *image = [UIImage imageWithData:imageData];
dispatch_async(dispatch_get_main_queue(), ^{
cellImg.image = image;
});
});
return cell;
}
i need download image from url and load it into UIIamge view
first i get image from URL , but data return with nil i dont know why ?
-(UIImage *) getImageFromURL:(NSString *)fileURL {
UIImage * result;
// data here return with nil
NSData * data = [NSData dataWithContentsOfURL:[NSURL URLWithString:fileURL]];
result = [UIImage imageWithData:data];
return result;
}
You can use AFNetworking
And simply use: - (void)setImageWithURL:(NSURL *)url;
Or something more complex:
UIImageView image;
NSString *urlstring = [NSString stringWithFormat:#"http://url/"];
NSURL *url = [NSURL URLWithString:urlstring];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
[image setImageWithURLRequest:request
placeholderImage:[UIImage imageNamed:#"placeholder.png"]
success:^(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image){
// Succes on loading image
}
failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error){
// Fail to load image
}];
You can set your image from URL link like this:
NSString *your_url = #"http://your_link/";
image_View.image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:your_url]]];
Also refer :
1) question 1
2) question 2
3) question 3
I am writing an app that displays images from url in a view. The idea is that when the view appears, image is dowloaded and it actualizes a UIImamgeView in the view.
I am using a Asyncrounse method in this way:
-(void)downloadASyncro:(NSString*)urlLink{
NSURL * imageURL = [NSURL URLWithString:urlLink];
[self downloadImageWithURL:imageURL completionBlock:^(BOOL succeeded, UIImage *image) {
if (succeeded) {
NSLog(#"scaricaImmagineASyncro Succeded= %#",image);
picView.image = image;
}
else {
//default image
picView.image = [UIImage imageNamed:#"icon_old.jpg"];
}
}];
}
the downloadImageWithURL method is:
- (void)downloadImageWithURL:(NSURL *)url completionBlock:(void (^)(BOOL succeeded, UIImage *image))completionBlock
{
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
[NSURLConnection sendAsynchronousRequest:request
queue:[NSOperationQueue mainQueue]
completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) {
if ( !error )
{
UIImage *image = [[UIImage alloc] initWithData:data];
completionBlock(YES,image);
} else{
completionBlock(NO,nil);
}
}];
}
When I call the method:
[self downloadASyncro:link];
and the operation sees end with success (NSLOG), picView.image = image; should actualize the view showing the image downloaded , should not it? But immage does not appear...
Any idea? Thanks in advance.