2014/10/15 下午 10:07:36

iphone Programming Glossary: drawincontext

http://stackoverflow.com/questions/14192816/create-a-custom-animatable-property

iphone ios uiview core animation share improve this question If you extend CALayer and implement your custom void drawInContext CGContextRef context You can make an animatable property by overriding needsDisplayForKey in your custom CALayer class like..

iPhone development: pointer being freed was not allocated

http://stackoverflow.com/questions/1424210/iphone-development-pointer-being-freed-was-not-allocated

CA Transaction CALayerDisplayIfNeeded CALayer _display CABackingStoreUpdate backing_callback CGContext void CALayer drawInContext UIView CALayerDelegate drawLayer inContext AvatarView drawRect AvatarView overlayPNG UIImageUtility createMaskOf UIGraphicsGetImageFromCurrentImageContext..

composite colors: CALayer and blend mode on iPhone

http://stackoverflow.com/questions/1658751/composite-colors-calayer-and-blend-mode-on-iphone

drawRect CGRect rect CGContextRef c UIGraphicsGetCurrentContext CGContextSetBlendMode c kCGBlendModeDifference myLayer drawInContext c BTW I did not add the layers as sublayers of the view's layer that is I never called myView.layer addSublayer myLayer..

Add text to CALayer

http://stackoverflow.com/questions/2209734/add-text-to-calayer

text to CALayer Is it possible to add a UILabel to a CALayer without subclassing and drawing it in drawInContext Thanks iphone share improve this question I don't think you can add a UIView subclass to a CALayer object. However.. as shown below. While my code is done in the delegate's drawLayer inContext method the same can be used in subclass' drawInContext method. Is there any specific UILabel functionality that you want to leverage void drawLayer CALayer layer inContext CGContextRef..

How Do I Take a Screen Shot of a UIView?

http://stackoverflow.com/questions/2214957/how-do-i-take-a-screen-shot-of-a-uiview

image. UIGraphicsBeginImageContext CGSizeMake 320 480 CGContextRef context UIGraphicsGetCurrentContext myUIView.layer drawInContext context UIImage screenShot UIGraphicsGetImageFromCurrentImageContext UIGraphicsEndImageContext myUIView has dimensions 320x480.. iphone objective c uiview uiimage screenshot share improve this question I think you may want renderInContext not drawInContext . drawInContext is more a method you would override... Note that it may not work in all views specifically a year or so.. c uiview uiimage screenshot share improve this question I think you may want renderInContext not drawInContext . drawInContext is more a method you would override... Note that it may not work in all views specifically a year or so ago when I tried..

Disabling implicit animations in -[CALayer setNeedsDisplayInRect:]

http://stackoverflow.com/questions/2244147/disabling-implicit-animations-in-calayer-setneedsdisplayinrect

implicit animations in CALayer setNeedsDisplayInRect I've got a layer with some complex drawing code in its drawInContext method. I'm trying to minimize the amount of drawing I need to do so I'm using setNeedsDisplayInRect to update just the..

Animating a custom property of CALayer subclass

http://stackoverflow.com/questions/2395382/animating-a-custom-property-of-calayer-subclass

key if key isEqualToString @ myInt return YES else return super needsDisplayForKey key Use the value of myInt in your drawInContext method. Now when you animate myInt Core Animation will interpolate the values for each step of the animation and repeatedly..

How Do I Save What I have Drawn In A CGContext

http://stackoverflow.com/questions/2568421/how-do-i-save-what-i-have-drawn-in-a-cgcontext

Do I Save What I have Drawn In A CGContext I have drawn into a CGContext of a UIView. void drawRect CGRect rect self drawInContext UIGraphicsGetCurrentContext I would like to save what I have drawn to a png file. Is there a simple solution EDIT Based.. imageData UIImagePNGRepresentation image imageData writeToFile outFile atomically NO void drawRect CGRect rect self drawInContext UIGraphicsGetCurrentContext self createImage iphone cocoa touch uiview share improve this question UIImage image UIGraphicsGetImageFromCurrentImageContext..

iPhone, CGPDFDocument - PDF links

http://stackoverflow.com/questions/3257057/iphone-cgpdfdocument-pdf-links

links I'm trying to write a simple PDF viewer using CGPDFDocument based on QuartzDemo. There is common rendering void drawInContext CGContextRef context PDF page drawing expects a Lower Left coordinate system so we flip the coordinate system before we..

How do I adjust a Quartz 2D context to account for a Retina display?

http://stackoverflow.com/questions/3896968/how-do-i-adjust-a-quartz-2d-context-to-account-for-a-retina-display

setContentScaleFactor view.contentScaleFactor UIScreen mainScreen scale the 2 D drawing you do within drawRect or drawInContext will be automatically rendered sharply for the Retina display. Remember that the coordinates you specify for the Quartz..

Why animating custom CALayer properties causes other properties to be nil during animation?

http://stackoverflow.com/questions/4016496/why-animating-custom-calayer-properties-causes-other-properties-to-be-nil-during

I have a custom CALayer say CircleLayer containing custom properties radius and tint . The layer renders itself in its drawInContext method. void drawInContext CGContextRef ctx NSLog @ Drawing layer tint is @ radius is @ self.tint self.radius CGPoint centerPoint.. CircleLayer containing custom properties radius and tint . The layer renders itself in its drawInContext method. void drawInContext CGContextRef ctx NSLog @ Drawing layer tint is @ radius is @ self.tint self.radius CGPoint centerPoint CGPointMake CGRectGetWidth.. circleLayer addAnimation theAnimation forKey @ animateRadius circleLayer.radius NSNumber numberWithDouble 50.0 drawInContext gets called as expected during the animation to redraw the circle however the tint is set to nil as soon as the animation..

“failed to resume in time” on resumption from background crash

http://stackoverflow.com/questions/4414467/failed-to-resume-in-time-on-resumption-from-background-crash

48 16 UIKit 0x000132d2 UIView CALayerDelegate drawLayer inContext 258 17 QuartzCore 0x000152fe CALayer drawInContext 86 18 QuartzCore 0x0001507c backing_callback CGContext void 32 19 QuartzCore 0x00014af2 CABackingStoreUpdate 1226 20 QuartzCore..

Creating a custom text-drawing view

http://stackoverflow.com/questions/844829/creating-a-custom-text-drawing-view

CALayers one after another but I am having trouble drawing content to the layers using drawLayer inContext and drawInContext . So my questions are Does anyone have any even general suggestions about how to accomplish either of these two points...

How to capture current view screenshot and reuse in code? (iPhone SDK)

http://stackoverflow.com/questions/879064/how-to-capture-current-view-screenshot-and-reuse-in-code-iphone-sdk

you window drawRect won't work. Most views don't implement drawRect and it's certainly not recursive like on the mac. drawInContext is also pretty much hosed simalarly as it's fundamentally asking the layer to draw itself not its sublayers recursively...