iOS how to get a file(image) from a given folder

tranvutuan · Dec 25, 2011

Hello everyone
Here is the directory of my images located shown in the right panel of my Xcode:

Code:

-My project
                ---Classes
                ---Resources
                           ----- folder1
                                      ------- [B]img1[/B] (poor quality)
                                      ------- img2
                           ----- folder2
                                      ------- img1 (high quality )
                                      ------- img2

Notice that img1 is also in folder1 and folder2 but they are difference in quality. Now, I have an UIImageView and my goal is set img1 (high quality) as a background of my UIImageView. Here what I coded

Code:

[bigViewOfImg setImage:[UIImage imageNamed:@"Resources/folder1/img1"]];

However, the img is now not shown on UIImageView. .
Others tell me that change the name of 2 imges and code like below

Code:

[bigViewOfImg setImage:[UIImage imageNamed:@"img1.png"]];

For some reason, i dont want to change the name of my imges.Therefore, how can I point to the right folder so that I properly pull out the image which I want to....

KnightWRX · Dec 25, 2011

Have a look at NSBundle's pathForResource:ofType:inDirectory:, along with mainBundle in the same class, then think of how you can use these along with UIImage's initWithContentsOfFile:.

EDIT : of course, if your code already uses UIImage's class method imageNamed:, you might want to use [UIImage imageWithContentsOfFile:] instead of my prior suggestion of initWithContentsOfFile:.

ArtOfWarfare · Dec 25, 2011

Your images will all appear in the same directory after you build your app.

The left panel (you got your left and right backwards in your opening post) displays things as being within folders only for convenience... To help keep your app files organized. In reality they will all be heaped into a single bundle with no subdirectories on the iPhone.

Thus, do not name multiple files the same thing, regardless of how you've organized them in Xcode.

You said the images were identical, except for quality. By this do you mean retina quality vs. pre-retina quality? If so, add "@2x" after the name, but before the extension, of the higher quality, retina, image, so that Xcode will know that the high quality image should be displayed on the iPhone 4 and 4S while the low quality one should be displayed on the 3GS.

tranvutuan · Dec 25, 2011

KnightWRX said:
Have a look at NSBundle's pathForResource:ofType:inDirectory:, along with mainBundle in the same class, then think of how you can use these along with UIImage's initWithContentsOfFile:.

EDIT : of course, if your code already uses UIImage's class method imageNamed:, you might want to use [UIImage imageWithContentsOfFile:] instead of my prior suggestion of initWithContentsOfFile:.

I just gave it a tried like below

Code:

NSString *filePath = [[NSBundle mainBundle] pathForResource:@"img1" ofType:@"png" inDirectory:@"[U]Resource/folder1[/U]" ];

However, when I debugged by printing the filepath on the console, it is
filePath is (null)
I also tried like below

Code:

NSString *filePath = [[NSBundle mainBundle] pathForResource:@"img1" ofType:@"png" inDirectory:@"[U]folder1[/U]" ];

But it does not work either....

----------

ArtOfWarfare said:
Your images will all appear in the same directory after you build your app.

The left panel (you got your left and right backwards in your opening post) displays things as being within folders only for convenience... To help keep your app files organized. In reality they will all be heaped into a single bundle with no subdirectories on the iPhone.

Thus, do not name multiple files the same thing, regardless of how you've organized them in Xcode.

You said the images were identical, except for quality. By this do you mean retina quality vs. pre-retina quality? If so, add "@2x" after the name, but before the extension, of the higher quality, retina, image, so that Xcode will know that the high quality image should be displayed on the iPhone 4 and 4S while the low quality one should be displayed on the 3GS.

They are same imges but one is small size of 70X70 and the other is big size of 200X200. So if I add"@2x", which one should be added, the small or the large one..

KnightWRX · Dec 26, 2011

tranvutuan said:
But it does not work either....

Nope, I checked after what ArtofWarfare posted and indeed, Xcode builds IPA bundles as one big mess. Just go to your build folder and do a show package on your bundle and you'll see everything is lumped into the root folder of the package.

tranvutuan said:
They are same imges but one is small size of 70X70 and the other is big size of 200X200. So if I add"@2x", which one should be added, the small or the large one..

His trick was for Retina vs non-Retina display. It seems to me you want to do thumbnail previews and full display images. You'll have to work out yourself how to send 2 different strings instead of folder names to your classes.

dejo · Dec 26, 2011

KnightWRX said:
Nope, I checked after what ArtofWarfare posted and indeed, Xcode builds IPA bundles as one big mess. Just go to your build folder and do a show package on your bundle and you'll see everything is lumped into the root folder of the package.

Yes, by default it's one big folder. It is, however, possible to create and use subfolders within it but it is rarely done because hardly anybody spends time in the IPA Package Contents. It is more important to make sure you have things organized within Xcode, where you do spend your time, and that is done via Groups.

KnightWRX · Dec 26, 2011

dejo said:
Yes, by default it's one big folder. It is, however, possible to create and use subfolders within it but it is rarely done because hardly anybody spends time in the IPA Package Contents. It is more important to make sure you have things organized within Xcode, where you do spend your time, and that is done via Groups.

Well, seems for the OP it would be a good solution if his code already relies on the sub-folders. If it is doable, he could then apply the NSBundle method I gave him which would be simpler than re-factor his code for different image names I guess.

tranvutuan · Dec 26, 2011

KnightWRX said:
Nope, I checked after what ArtofWarfare posted and indeed, Xcode builds IPA bundles as one big mess. Just go to your build folder and do a show package on your bundle and you'll see everything is lumped into the root folder of the package.

His trick was for Retina vs non-Retina display. It seems to me you want to do thumbnail previews and full display images. You'll have to work out yourself how to send 2 different strings instead of folder names to your classes.

yeah I want to do thumbnail and fully display images. The images are same name but different folders. That is why I have to figure out how to get their directory properly so that I can point to the right image

KnightWRX · Dec 26, 2011

tranvutuan said:
yeah I want to do thumbnail and fully display images. The images are same name but different folders. That is why I have to figure out how to get their directory properly so that I can point to the right image

I found something that explains how to do what Dejo said :

http://www.iphonedevsdk.com/forum/iphone-sdk-development/6457-xcode-folder-directories.html

This guy seems to want to do the same thing you are doing. After that, the NSBundle trick should work.

tranvutuan · Dec 26, 2011

KnightWRX said:
I found something that explains how to do what Dejo said :

http://www.iphonedevsdk.com/forum/iphone-sdk-development/6457-xcode-folder-directories.html

This guy seems to want to do the same thing you are doing. After that, the NSBundle trick should work.

Yeah it is what I am searching for... Thanks a lot....

jnoxx · Dec 27, 2011

You can copy resources into a Bundle via Xcode, then you can look for items in a specific subfolder. this is done by opening xcode.
Clicking on build phases (where you add frameworks).
There you can add a Build Phase, where you can set it all up

tranvutuan · Dec 27, 2011

KnightWRX said:
I found something that explains how to do what Dejo said :

http://www.iphonedevsdk.com/forum/iphone-sdk-development/6457-xcode-folder-directories.html

This guy seems to want to do the same thing you are doing. After that, the NSBundle trick should work.

Now, I can pull the img from my folder1 by

Code:

[bigViewOfImg setImage:[UIImage imageNamed:@"folder1/img1.png"]];

My next task is to print all path of my imges ( img1 + img2 )from my folder1. To do so, I do

Code:

NSArray *tmp    =   [NSBundle pathsForResourcesOfType:@"png" inDirectory:[[NSBundle mainBundle] bundlePath]];

and I got so many result and what is not I expected. In the documentation.. they define

Code:

[[NSBundle mainBundle] bundlePath] = the top level of bundle

but my directory is a sub-directory...
Please advice me on this issue..... Thanks a lot

dejo · Dec 27, 2011

What is your understanding of the purpose of the inDirectory parameter in the [NSBundle pathsForResourcesOfType:inDirectory:] method?

tranvutuan · Dec 27, 2011

dejo said:
What is your understanding of the purpose of the inDirectory parameter in the [NSBundle pathsForResourcesOfType:inDirectory:] method?

Following to the definition at http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSBundle_Class/Reference/Reference.html and What I have to derived by coding to test it like

Code:

NSArray *tmp= [NSBundle pathsForResourcesOfType:@"png" inDirectory:@"[B]Resource/folder1[/B]"];
    for (id obj in tmp )
        NSLog(@"%@",tmp); // [B]it give me null ---->NSArray is empty----->path not exist somehow[/B]

Therefore, I think inDirectory must be a directory in which myProject.app is located.
If I have made a mistake, pls correct me. Thanks

dejo · Dec 27, 2011

tranvutuan said:

Accuracy is very important in programming. Resource/folder1 is not the same as Resources/folder1, which is the folder name you claimed to have in your project in your original post.

tranvutuan · Dec 27, 2011

dejo said:
Accuracy is very important in programming. Resource/folder1 is not the same as Resources/folder1, which is the folder name you claimed to have in your project in your original post.

Im sorry it was my typo... Actually what I did was

Code:

NSArray *tmp= [NSBundle pathsForResourcesOfType:@"png" inDirectory:@"[B]Resources[/B]/folder1"];

dejo · Dec 27, 2011

tranvutuan said:
Im sorry it was my typo...

When you include code-snippets, whenever possible you should copy-and-paste them from the actual Xcode project. That way, the code we are attempting to help you debug is the same code that you have written.

tranvutuan said:

So, now that you've given us the correct code, what is it doing? Or not doing?

tranvutuan · Dec 27, 2011

dejo said:
When you include code-snippets, whenever possible you should copy-and-paste them from the actual Xcode project. That way, the code we are attempting to help you debug is the same code that you have written.

So, now that you've given us the correct code, what is it doing? Or not doing?

I am sorry to confuse you then...Given a right path :Resources/folders, I would like to get all full pathnames for all files with the an extension of "png"

dejo · Dec 27, 2011

tranvutuan said:
I am sorry to confuse you then...Given a right path :Resources/folders, I would like to get all full pathnames for all files with the an extension of "png"

Yes, I already understand what it is you're trying to do. But what does the code you've provided actually do, or not do? That is, what is the value of tmp after you run that line of code? Is it nil? If it is, what have you done in terms of debugging to determine why it's nil? If it isn't nil, what is does it contain? And does what it contain match up with what you expect it to contain? If not, ...

In other words, what basic debugging have you done?

tranvutuan · Dec 27, 2011

dejo said:
Yes, I already understand what it is you're trying to do. But what does the code you've provided actually do, or not do? That is, what is the value of tmp after you run that line of code? Is it nil? If it is, what have you done in terms of debugging to determine why it's nil? If it isn't nil, what is does it contain? And does what it contain match up with what you expect it to contain? If not, ...

In other words, what basic debugging have you done?

The debugger gave me nothing when I tried to print the contents ( all path type of string of png files ).That is why I guess my NSArray is nil then...
Im not so sure about the method which I invoked,I think I used the wrong one because the inDirectory parameter should be the top level directory of a bundle. However, I was passing a sub-path as an argument.....

tranvutuan · Dec 28, 2011

dejo said:
Yes, I already understand what it is you're trying to do. But what does the code you've provided actually do, or not do? That is, what is the value of tmp after you run that line of code? Is it nil? If it is, what have you done in terms of debugging to determine why it's nil? If it isn't nil, what is does it contain? And does what it contain match up with what you expect it to contain? If not, ...

In other words, what basic debugging have you done?

Hey I know why my tmp is NIL now...The reason is I have not initialize my bundle yet...
When I made a small change of my code to

Code:

NSArray *tmp= [[B][NSBundle mainBundle] [/B]pathsForResourcesOfType:@"png" inDirectory:@"Resources/folder1"];

Then I can pull out all of the path of png file...Thanks for your help after all....

KnightWRX · Dec 28, 2011

tranvutuan said:
Hey I know why my tmp is NIL now...The reason is I have not initialize my bundle yet...

KnightWRX said:
Have a look at NSBundle's pathForResource:ofType:inDirectory:, along with mainBundle in the same class

iOS how to get a file(image) from a given folder

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