uiscrollview not scrolling uiimageview - iphone

I'm trying to insert one more image in my UIScrollView. The problem is: all my old content is still scrollable, but this image stay static in the top of the page. Does anybody know a solution?
Code:
- (void)viewDidLoad {
CGRect myImageRect = CGRectMake(0.0f, 0.0f, 320.0f, 109.0f);
myImage = [[UIImageView alloc] initWithFrame:myImageRect];
UIImage * img = [[UIImage alloc] initWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:#"www.somelink.com"]]];
myImage.image = img;
myImage.opaque = YES; // explicitly opaque for performance
[scrollView addSubview:myImage];
[myImage release];
}
Regards.


I'm guessing that your "old content" is encapsulated in a view and it's that view that is your UIScrollView's subview for content. If that's the case, you should add your new image to that "contentView", adjust its frame and update the scrollview's contentSize based on the new width and height of the content view.
If my guess is wrong, could you please post the code showing how the UIScrollView is created and how the "old content" is added to it?
You might also find this sample code from Apple useful with regard to the layout of subviews of a UIScrollView. (see the - (void)layoutScrollImages method).

Related

Scrollbar doesn't show up

I'm new to ios programming.
I want users to be able to scroll screen, so I initialized UIScrollView and add other views into the instance of UIScrollView.
But, I'm not able to scroll screen and I don't see a scrollbar.
This is my code I wrote.
This view controller extends from UIViewController.
What is wrong with this?
Please help me.
Thank you very much!!
- (void)viewDidLoad
{
[super viewDidLoad];
UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:self.view.frame];
scrollView.contentSize = self.view.frame.size;
[self.view addSubview:scrollView];
UIImage *img = [UIImage imageNamed:#"avatar.png"];
UIImageView *profileImg = [[UIImageView alloc] initWithImage:img];
CGPoint newPoint = self.view.center;
newPoint.y = 300;
profileImg.center = newPoint;
[scrollView addSubview:profileImg];
}

you need to set a content size and scroll enabled
[scrollView setFrame:self.view.bounds]; // not needed to be able to scroll
[scrollView setScrollEnabled:YES]; // needed to be able to scroll, defaults to YES
[scrollView setContentSize:CGSizeMake(320, 500)]; // the important part that is needed to be able to scroll
the 320 and 500 are desired maxed distances of scrolling to, this is not the actual scroll distance but the width and height of pixels that will be shown, you can think of the scroll view being a window and these values being the world outside
that is where you main error is, the width and height of your scroll view is the same width and height of the context size, therefore; it's like you are looking through a 1ft by 1ft window in to a room that is only 1ft by 1ft
UIScrollView Documentation

uiimageview aspectfit question

I've use a imagepicker to select image from my photo library, then i display that image in an uiimageview. Landscape photo works fine but there is some weirdness to the portrait image. The portrait image suppose to fill up the left and right empty space but it's not.
Cant figure out why the picture wont fill up the left and right space cause the imageview frame did specify the mainScreen bounds.
If i take away the aspectfit then the potrait image is nicely display but the landscape image is stretched to fill up the whole imageview.
My code is as follow:
CGRect frame = [[UIScreen mainScreen] bounds];
UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:frame];
UIImageView *selectedImageView = [[UIImageView alloc] initWithFrame:frame];
selectedImageView.image = image;
selectedImageView.contentMode = UIViewContentModeScaleAspectFit;
[scrollView addSubview:selectedImageView];
[selectedImageView release];
scrollView.delegate = self;
[self.view addSubview:scrollView];
[scrollView release];
Here is what it looks like:
Edit: My goal is to display the photo like it's been display in Photos album, start out as fitting in the view and allow zoom in to a certain limit.

Try out
UIImageView *logoImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"logo_bg.png"]];
[logoImageView setFrame:CGRectMake(0, 0, 320, [UIImage imageNamed:#"logo_bg.png"].size.height)];
[mainView addSubview:logoImageView];

how can I use UIImageView on full screen in UIViewController?

I am developing a software and in it I am making a new file, which is subclass of UIViewController, when I do use UIImageView, then there is little border remaining in it, what should I do so that my image should cover all area around it,
my coding of UIImageView in ViewDidLoad is
UIImageView* view = [[UIImageView alloc] initWithImage: [UIImage imageNamed: #"frontnew.png"]];
view.frame = CGRectMake(0, 0, 320, 415);
[self.view addSubview:view];
now what should I do ????
If I increase height and width then it will increase from two sides, not all ???

you should set imageview property as scalltoFit
May be it can help you

Load dynamic Image in tableHeaderView

I want to add a dynamic image in the UITableView's tableHeaderView part.
For that i am writing following code :
UIImageView *myImageView = [[UIImageView alloc]initWithFrame: CGRectMake(0.0f,
0.0f,
320.0f,
44.0f)];
self.tableView.tableHeaderView = myImageView;
[myImageView release];
With this code i am getting image in my screen, but with stretched view.
Now i want to set that image at the particular corner of HeaderView of table.
Anyone have any solution then please help me..
Thanks in advance..

Add your UIImageView to a regular container UIView and place it inside that.

UIImageView change Width and Height

I've read various posts on here asking similar questions... I've tried various ways that were posted including bounds and frames etc. including the following:
myImage.frame = CGRectMake(0.0f, 0.0f,50.0f, 50.0f);
and:
myImage.bounds = CGRectMake(0.0f, 0.0f,50.0f, 120.0f);
neither of those work.
However, I find it interesting that the following code let's me move the Image around but doesn't change the width:
CGRect frameRect = myImage.frame;
frameRect.size.width = 50.0f;
frameRect.origin.x += 10.5f;
myImage.frame = frameRect;
So why don't any of these change the width/height of my ImageView?
I found another post on here that basically states I have to right a small book of code to get it resize my image... is that true?
Such as this one:
UIImage: Resize, then Crop
certainly this is simpler than that??

The following will change the size of the UIImaveView, clipping the underlying image without resizing it and keeping it aligned to bottom left of view:
imageView.frame = CGRectMake(
imageView.frame.origin.x,
imageView.frame.origin.y, newWidth, newHeight);
imageView.contentMode = UIViewContentModeBottomLeft; // This determines position of image
imageView.clipsToBounds = YES;

First off, you can't set the frame or bounds of the UIImage - that will only work on a UIImageView.
I've found that changing the frame of a UIImageView causes the Image to be scaled to the new size. Sometimes, that's undesirable - and you want instead to crop the image.
I can't tell if this is what you're asking for, but here's some code to crop an image to a specific size in a UIImageView:
UIImage *myImage = [UIImage imageNamed:#"photo.png"];
CGRect cropRect = CGRectMake(0.0, 0.0, 320.0, 44.0));
CGImageRef croppedImage = CGImageCreateWithImageInRect([myImage CGImage], cropRect);
UIImageView *myImageView = [[UIImageView alloc] initWithFrame:cropRect];
[myImageView setImage:[UIImage imageWithCGImage:croppedImage]];
CGImageRelease(croppedImage);

From what I get of the question, the OP wanted to change the size of the UIImageView when the size of the container UIView is changed. The code below will do it...
UIView * foo = [[[UIView alloc] initWithFrame:CGRectMake(0, 0, 25, 25)] autorelease];
foo.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
UIImageView * bar = [[UIImageView alloc] initWithImage:
[UIImage imageNamed:#"test.png"]];
bar.autoresizingMask = foo.autoresizingMask;
[foo addSubview:bar];
[self.view addSubview:foo];
The key here are the foo.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight and the bar.autoresizingMask = foo.autoresizingMask; lines. Forget either of these, and the whole jigmarole will stop working.

Well, if your read the documentation about UIIMage you can notice that is impossible to change any parameter of an UIImage after create it, the solution I've implemented for use high quality images for change some parameter of (for example) the SliderControl as Screw Image, is the next one:
UIImage *tumbImage= [UIImage imageNamed:#"screw.png"];
UIImage *screw = [UIImage imageWithData:UIImagePNGRepresentation(tumbImage) scale:2];
With that, I can to use 100x100 px image in my apps scaled to 50%.
Kind regards.

Try Using a UIScrollView. Add the UIImageView to the UIScrollView in Interface Builder you can then control the position and size of the image as follows:
CGRect rect = [scrollView frame];
rect.origin.x = 50.0f;
rect.origin.y = 0.0f;
rect.size.width = 320.0f;
rect.size.height = 150.0f;
[scrollView setFrame:rect];

If you tried those methods cannot work, the only way to do it is to add the constraint of width and height to the UIImageView.
// Create the constraint in code
NSLayoutConstraint *constraint0 = [NSLayoutConstraint constraintWithItem: myImage attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeWidth multiplier:1.0f constant: yourNewsWidth];
NSLayoutConstraint *constraint1 = [NSLayoutConstraint constraintWithItem: myImage attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeHeight multiplier:1.0f constant: yourNewsHeight];
[myImage addConstraint:constraint0];
[myImage addConstraint:constraint1];

Use myImageView.frame = myNewPosAndSize; to resize or reposition your image view (as with any other view). It might confuse you that the image view draws its image with its original size, possibly exceeding its own dimensions. To disable this use myImageView.clipsToBounds = NO;

You don't have to write a whole book, you can copy that code.
I believe the UIImageView always draws the image at 0,0 at a 1.0 scale. You'll need to resize the image if you want to continue using the UIImageView.