i want to use Aspect Fit Mode in Draw in Rect Method.
[mainImageView.image drawInRect:CGRectMake(0, 0,mainImageView.frame.size.width,mainImageView.frame.size.height)];
when i show an image in MainImage View it show in scale to fill mode . I want to show it in Aspect to Fit Mode. how can i do it.can someone help me.
Implement it in below way:
UIImageView *imgBg = [[UIImageView alloc] initWithFrame:CGRectMake(0.0, 0.0, 195.0, 39.0)];
[imgBg setImage:[UIImage imageNamed:#"bg_dropdown.png"]];
[imgBg setContentMode:UIViewContentModeScaleAspectFit];
Let me know in case of any difficulty.
Cheers
Probably you forgot to mention
[self addSubview:imgBg];
at the end of the code
If all what you want is just:
I want to show it in Aspect to Fit Mode
You can set content mode of your Image View:
mainImageView.contentMode = UIViewContentModeScaleAspectFit;
But if you want your image to be drawn in the graphics context with that content mode, you can draw the whole view instead of using drawInRect:
mainImageView.contentMode = UIViewContentModeScaleAspectFit;
[mainImageView drawViewHierarchyInRect:view.bounds
afterScreenUpdates:NO];
Related
I have uiview and i want to convert that view to image which is working quite well but when i pressed the home button of iphone and run the app again the image become zoom in .Here is my code to converting view to image.
- (UIImage *)captureView {
CGRect rect = [myview bounds];
UIGraphicsBeginImageContext(rect.size);
CGContextRef context = UIGraphicsGetCurrentContext();
[myview.layer renderInContext:context];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
checkImage.image = [self captureView];
here this code is not wrong but you used some other object instead of whole view . i don't know but try to use that view bounds in which that whole Image display.. See my answer same like your this answer from this bellow link..
how to capture uiview top uiview
Also try with self.view instead of myView in your code.
add this code instead of your checkImage.image = [self captureView]; line..
UIImageView *imgTempHeader = [[UIImageView alloc]initWithImage:[self captureView]];
imgTempHeader.frame = self.view.frame;
[self.view addSubview:imgTempHeader];
[self.view bringSubviewToFront:imgTempHeader];
You should be creating the context in a way which uses the scale of the device:
UIGraphicsBeginImageContextWithOptions(rect.size, NO, 0);
Then when you display the image in the image view ensure that the content mode is set to prevent scaling.
My experience is with setting up imageViews in IB. I assume checkImage is an instance of UIImageView?
If you were displaying an image in a UIImageView and had only set the view mode to center in interface builder it would appear zoomed in if the image was large.
Have a look at this way to process your image first:
UIImage *newImage = [[UIImage alloc] initWithCGImage:myCGImageRef scale:myZoomSCale orientation:UIImageOrientationDown];
Of course you will need to give it a CGImageRef for your image. Over to you or somebody else for that.
At this moment, my program looks like this:
As you can see, the square with the rounded rectangles is an image but it doesn't show very well and am not sure how to solve this... Here is the class: http://pastebin.com/QPXbG1uK
The background window gets added here:
UIImageView* background = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"popupWindowBack.png"]] ;
background.center = CGPointMake(_bigPanelView.frame.size.width/2, _bigPanelView.frame.size.height/2);
[_bigPanelView addSubview: background];
Also what do I need to change if I want a simple view as the background instead of the image?
In Your place I would stop using Center coordinates and specifically set it's frame rectangle:
background.contentMode = UIViewContentModeScaleAspectFit;
background.frame = CGRectMake(10,10,_bigPanelView.frame.size.width-20, _bigPanelView.frame.size.height-20);
In this case - imageview will be 10 pix from top/left/right/bottom.
Remove this:
background.center = CGPointMake(_bigPanelView.frame.size.width/2, _bigPanelView.frame.size.height/2);
If you want to achieve your image fit your UIImageView try this:
background.contentMode = UIViewContentModeScaleAspectFit;
Also you need to set background frame to fit screen size, for example if you adding UIImageView in UIViewController class instance:
background.frame = self.view.frame;
i think your image size is larger then bigPanelView view . plz set the background frame size of the bigPanelView. like
background.frame = bigPanelView.view.frame;
According to the official doc on UIView about the contentMode property:
The content mode specifies how the cached bitmap of the view’s layer is adjusted when the view’s bounds change
What's defined the content in this definition? Is it a sub view or when we have define a background color for a view for example.
My very first guess was that it should apply at least for the subviews in a view, but for example the following code snippet will not give me the expected result when playing with the UIViewContentModeCenter tag:
UIView* redView = [[UIView alloc] initWithFrame:CGRectMake(80, 80, 150, 200)];
redView.contentMode = UIViewContentModeCenter;
redView.backgroundColor = [UIColor redColor];
UIView* greenView = [[UIView alloc] initWithFrame:redView.bounds];
greenView.backgroundColor = [UIColor greenColor];
[redView addSubview:greenView];
redView.frame = CGRectInset(redView.frame, -5, -5);
[self.view addSubview:redView];
I have just set up a redView that will include a greenView. I have also set-up the content mode of the redview to UIViewContentModeCenter - why in the code I wrote the greenView is not centered when I change the frame of its parent? isn't what UIViewContentModeCenter is supposed to do?
Thanks for clarifying!
Ps: You can easily test the above code in the loadView of a simple view controller template project.
From the documentation:
The content mode specifies how the cached bitmap of the view’s layer
is adjusted when the view’s bounds change.
For an image view, this is talking about the image. For a view that
draws its content, this is talking about the drawn content. It does
not affect the layout of subviews.
You need to look at the autoresizing masks in place on the subviews.
Content mode is a red herring here. If you can't achieve the layout
you need using autoresizing masks, then you need to implement
layoutSubviews and calculate the subview positions and frames
manually.
from jrturton's answer to: https://stackoverflow.com/a/14111480/1374512
First read about Content Modes here
In your example you change the frame of the red view. That will invoke layoutSubviews on the view which will reposition the green view according to the layout constraints or autoresizing masks. You haven't specified any. So the frame of the green view will stay the same.
The content mode specifies how the view's layer should update when resizing. Depending on the content mode drawRect will be called or not.
You can test the effect of the different content modes with the following example:
Add a UIView subclass, that draws a circle using this drawRect implementation:
- (void)drawRect:(CGRect)rect
{
// Drawing code
NSLog(#"drawRect %#", NSStringFromCGRect(rect));
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextAddEllipseInRect(ctx, self.bounds);
[[UIColor redColor] setFill];
CGContextFillPath(ctx);
}
In the view controller create and add the circle view:
CircleView* circleView = [[CircleView alloc] initWithFrame:CGRectMake(10, 10, 20, 20)];
circleView.contentMode = UIViewContentModeCenter; // <- try different modes here
[self.view addSubview:circleView];
Now lets animate the frame and see what happens:
dispatch_async(dispatch_get_main_queue(), ^{
[UIView animateWithDuration:5 animations:^{
circleView.frame = CGRectMake(10, 10, 100, 200);
}];
});
I'm doing that asynchronously to force CoreGraphics to draw the view at least one time with the original frame.
When you don't set the content mode you end up with a blurry circle, because it just scales up without redrawing. UIViewContentModeCenter makes the small circle stay at the center - also no redraw needed. UIViewContentModeRedraw makes the view draw the view again with the new frame. Actually that happens before the animation starts.
Note that the content mode can affect the drawing performance.
Hello i want to override drawrect in my custom annotationView, so when i write
[[_mapView viewForAnnotation:annotation] setNeedsDisplay];
my annotation view will be redrawn and i wouldn't have to remove the annotation and add it again.
here is my drawRect
- (void)drawRect:(CGRect)rect {
UIImage* theImage = nil;
if( _pinType == T_UNKNOWN ) theImage = [UIImage imageNamed:#"imgU.png"];
else theImage = [UIImage imageNamed:#"imgK.png"];
[theImage drawInRect:rect];
}
The problem is that my images are with alpha and the alpha part is black.
So maybe anyone knows the solution or some suggestions to this?
I've read a lot of post about this, also using core graphics, but didn't find the solution..
Thanks in advance!
Do you want this view to be partially transparent and display things under it? If so, use [self setOpaque:NO]. An opaque view's drawRect is responsible for drawing every pixel in the rectangle with a fully opaque color.
This function will be work correct for iOS 5.0. When you will use iOS version < 5.0, you'll got alpha part as black.
To try use another method for draw your images. I don't know for what you use this code. To try use:
UIImageView *image = [[UIImageView alloc] initWithImage: theImage];
image.opaque = NO;
[self.view addSubview: image];
When you try deleting a note in iPhone's Notes application, an UIActionSheet pops up. The sheet is translucent (but not black translucent). How is that achieved? Is it possible to make the background of UIActionSheet a certain color?
I usually implement the following delegate method:
- (void)willPresentActionSheet:(UIActionSheet *)actionSheet
Just to make a sample. In this case I use a stretched png as a background:
- (void)willPresentActionSheet:(UIActionSheet *)actionSheet {
UIImage *theImage = [UIImage imageNamed:#"detail_menu_bg.png"];
theImage = [theImage stretchableImageWithLeftCapWidth:32 topCapHeight:32];
CGSize theSize = actionSheet.frame.size;
// draw the background image and replace layer content
UIGraphicsBeginImageContext(theSize);
[theImage drawInRect:CGRectMake(0, 0, theSize.width, theSize.height)];
theImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
[[actionSheet layer] setContents:(id)theImage.CGImage];
}
and this is the result:
alt text http://grab.by/4yF1
You can use the code below:
actionSheetObj.actionSheetStyle=UIActionSheetStyleBlackOpaque;
or
actionSheetObj.actionSheetStyle=UIActionSheetStyleBlackTranslucent;
actionSheetObj.actionSheetStyle=UIActionSheetStyleBlackTranslucent;
It's not too difficult. You can use the following code:
CGSize mySize = myActionSheet.bounds.size;
CGRect myRect = CGRectMake(0, 0, mySize.width, mySize.height);
UIImageView *redView = [[[UIImageView alloc] initWithFrame:myRect] autorelease];
[redView setBackgroundColor:[UIColor colorWithRed:1.0 green:0.0 blue:0.0 alpha:0.5]];
[myActionSheet insertSubview:redView atIndex:0];
Just make sure you present the UIActionSheet before doing this or the size wont be set. That makes it kind of ugly, but you could do something like:
[myActionSheet showInView:self.view];
if (!redAdded) {
redAdded = YES;
//THE ABOVE CODE GOES HERE
}
You can definitely adjust the opacity by setting the alpha value. Interface Builder lets you edit the value directly, but in code I think you would do:
[[myActionSheet view] setOpaque:NO];
[[myActionSheet view] setAlpha:0.5];
I'm not sure if you need the setOpaque call or not - I think that is used to help optimize performance, as the iPhone won't try to render anything hidden by the opaque view.
It looks black to me (note: using 2.2.1). The only reason there's a color to it is because of the yellow behind it.
One option would be to use the black transparent background and find out the size and speed of the action sheet. Then create a view and animate it in at the same time you show the action sheet, just underneath it, to give it a tint different than the color naturally behind the action sheet. You would have to make the color view also translucent so you could see behind that as well.
I'm not sure if you can, but you might also try adjusting the opacity of the action sheet itself as well.