I have an image, that has transparent areas and a known backround. But wheh I set "image" property of the UIImage i see main view and not a color which i set in "background" property.
I think I tried that before and found no real solution. You could however put the uiimageview into an uiview with the same size and set the backgroundcolor to this view.
Had to create custom control with two UIImageViews bounded by obu UIView. It works, but i would prefer apple doing something about this behaviour
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I have a UIView has some labels and buttons on it.
Next I also have a image which has a square area that is transparent, now
if I create a UIImageView and add this image which has transparent regions I am not able to see the background view (which has buttons and labels) through this transparent image.
If I play with the alpha value that doesn't work as intended which is to see the transparent regions exactly as it would have appeared on the UIView which has the labels and buttons.
UIImage* image = [UIImage imageNamed:#"TI1.jpg"];
UIImageView* imageView = [[UIImageView alloc] initWithImage:image];
[self.view addSubview:imageView];
Also I would be interested to know if there is other way to achieve what I am trying to achieve.
Basically I want to highlight a certain area of the view which has buttons/labels and make the rest of the area greyed out. My idea was to have this UIImageView with transparent regions in image to achieve that.
Thanks
Ankur
Try setting imageView.opaque = NO;
UIImageView inherits from UIView. According to that class's docs:
This property provides a hint to the drawing system as to how it
should treat the view. If set to YES, the drawing system treats the
view as fully opaque, which allows the drawing system to optimize some
drawing operations and improve performance. If set to NO, the drawing
system composites the view normally with other content. The default
value of this property is YES.
Also, not sure that JPG even supports transparency, so try exporting the image as a PNG to ensure you get the results you're looking for.
I have a custom view for which I've (in the XIB) created a UIImageView as a subview. How can I make the image view appear in the background? (i.e. so that in the custom view I can create the hands of a clock that will appear over the top)
Do I need to make my background image have alpha areas for transparency? (if I have the terms correct) Or is it OK to have an image with it's background just set to white or black or whatever it needs to be (on the basis it will be in the background so this will be ok)
You can't: views are composited on top of their superviews, which means if your custom view is drawing in -drawRect:, it will always appear under the UIImageView.
The easiest way to achieve the effect you're looking for is to put the image view under your custom view in IB.
Background images generally do not need to have transparency (and there's a slight speedup if the PNG has no alpha channel).
An alternate approach to using UIImageView objects if you are drawing the rest of stuff in drawRect: is to use the image directly. Draw the image in drawRect: before you do any of the drawing.
Example
- (void)drawRect:(CGRect)rect {
[backgroundImage drawInRect:rect];
/* Do rest of your drawing */
}
Now this is only if you are using a complex image. If it is a texture, you would rather use UIColor's colorWithPatternImage: method to get a color from the UIImage object and set your custom view's backgroundColor. Remember that using the colorWithPatternImage: will not scale the image while drawing and will tile if the source image is smaller the frame of the view.
I have a translucent png image (made by turning down the opacity in Photoshop), and there's a UIImageView behind that translucent image. Is there any way to blur the parts of the UIImageView on the bottom that intersect with the UIImageView on top? Thanks!
Not aware of any code that will do that on its own, but you could 'fake it' by rendering the intersection of the views in a graphics context, then apply a blur effect to it. Then you could take the graphics context and insert a UIImageView with the resulting image in between the two views to simulate the effect. This method would not work very well if you have any sort of animation or otherwise changing the state of the images.
You may try setting alpha of the image to less than 1.
so I have a UIImageView in a UIView but when I run it in the iPhone Simulator, the image goes beyond the boundaries of the UIView. What's wrong...?
Have a look at the clipsToBounds property of UIView. If you set this to YES on your view the UIImageView shouldn't extend outside of that view any more.
You may also benefit from using the Content Mode property in which you can specify how the content is drawn to fit the view. You can set it to fill, fit-to-scale, etc.
I have a simple app that just displays a UIImageView. For some reason the image appears that it is partially transparent as it is much lighter than if I view the same image in photoshop. Any suggestions...I though by default a UIView is opaque.
You have probably changed the alpha of your imageView or the view itself. check for the the transparency of your imageview also. Because the default alpha of the imageview is 1 and opacity is also set to 100%. You might have chane one of these otherwise this is the problem of your image only
I don't believe that UIImageView is by default partially transparent? Try changing the background colour of the application and see if that affects the outcome of your image, if it is transparent it should be darker with a black background rather than white.