UIImageView change Width and Height

Question

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: http://stackoverflow.com/questions/603907/uiimage-resize-then-crop/605385#605385

certainly this is simpler than that??

Answer 1

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.

Answer 2

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;

Answer 3

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);

Answer 4

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.

Answer 5

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];

Answer 6

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;