ios - Swift - UIImageView zooms bigger than UIScrollView -


i'm having problem pinch zooming uiimageview set inside uiscrollview. image zooms in response user's pinch inputs, image zooms , gets bigger until takes entire screen rather staying inside bounds of uiscrollview. have had @ heap of different questions, articles , youtube videos try , find source of problem haven't been able find anything.

the following questions seem loosely related still couldn't resolve problem after looking @ them:

my uiscrollview created in storyboard , used layout constraints created in interface builder anchor in place. set scroll view's delegate self in viewdidload() (and have added uiscrollviewdelegate top of class). uiimageview created programmatically. declare image view @ top of class below:

class vcimageviewer: uiviewcontroller, uiscrollviewdelegate { @iboutlet weak var lblimagetitle: uilabel! @iboutlet weak var btnback: uibutton! @iboutlet weak var scrollview: uiscrollview!  var imageview:uiimageview = uiimageview()  // <-- image view

i add image view sub view of uiscrollview follow line of code, called during viewdidload():

self.scrollview.addsubview(self.imageview)

after adding image view scroll view, load image image view. fetch image url, , load in using following code. again, called in viewdidload().

self.imageview.image = uiimage(data: data)             self.imageview.frame = cgrect(origin: cgpoint(x: 0, y: 0), size: (self.imageview.image?.size)!)             if self.imageview.image != nil {                 self.lblerror.ishidden = true                 self.formatimageviewerwithimage()             }

this confirms image has loaded correctly, hides warning label display if hadn't, , calls self.formatimageviewerwithimage(), below:

func formatimageviewerwithimage() {     // constraints     let constraintimageviewtop:nslayoutconstraint = nslayoutconstraint(item: self.imageview, attribute: nslayoutattribute.top, relatedby: nslayoutrelation.equal, toitem: self.scrollview, attribute: nslayoutattribute.top, multiplier: 1, constant: 0)     let constraintimageviewbottom:nslayoutconstraint = nslayoutconstraint(item: self.imageview, attribute: nslayoutattribute.bottom, relatedby: nslayoutrelation.equal, toitem: self.scrollview, attribute: nslayoutattribute.bottom, multiplier: 1, constant: 0)     let constraintimageviewleft:nslayoutconstraint = nslayoutconstraint(item: self.imageview, attribute: nslayoutattribute.left, relatedby: nslayoutrelation.equal, toitem: self.scrollview, attribute: nslayoutattribute.left, multiplier: 1, constant: 0)     let constraintimageviewright:nslayoutconstraint = nslayoutconstraint(item: self.imageview, attribute: nslayoutattribute.right, relatedby: nslayoutrelation.equal, toitem: self.scrollview, attribute: nslayoutattribute.right, multiplier: 1, constant: 0)     self.view.addconstraints([constraintimageviewtop, constraintimageviewbottom, constraintimageviewleft, constraintimageviewright])      self.scrollview.contentsize = self.imageview.image!.size     self.scrollview.clipstobounds = false     let scrollviewframe = scrollview.frame     let scalewidth = scrollviewframe.size.width / self.scrollview.contentsize.width     let scaleheight = scrollviewframe.size.height / self.scrollview.contentsize.height     let minscale = min(scalewidth, scaleheight)     self.scrollview.minimumzoomscale = minscale      self.scrollview.maximumzoomscale = 1.0     self.scrollview.zoomscale = minscale }

i have implemented scrollviewdidzoom with:

func scrollviewdidzoom(_ scrollview: uiscrollview) {     self.centrescrollviewcontents() } func centrescrollviewcontents() {     let boundssize = self.scrollview.bounds.size     var contentsframe = self.imageview.frame     if contentsframe.size.width < boundssize.width {         contentsframe.origin.x = (boundssize.width - contentsframe.size.width) / 2     } else {         contentsframe.origin.x = 0     }     if contentsframe.size.height < boundssize.height {         contentsframe.origin.y = (boundssize.height - contentsframe.size.height) / 2     } else {         contentsframe.origin.y = 0     }     self.imageview.frame = contentsframe }

and viewforzooming with:

func viewforzooming(in scrollview: uiscrollview) -> uiview? {     return self.imageview }

i have seen previous questions (including listed above) suggested adding code viewwilllayoutsubviews(), have not had success that, viewwilllayoutsubviews() empty.

can see doing wrong?

please change line:

self.scrollview.clipstobounds = false

to line:

self.scrollview.clipstobounds = true

hope helps!


Comments

Post a Comment

Popular posts from this blog

python Tkinter Capturing keyboard events save as one single string -

is possible store keyboard events 1 string? code below stores 1 char , prints it. card reader or bar code reader, contains collection of character/ string not 1 character @ time. goal save char pressed text variable. from tkinter import * root = tk() def key(event): text= event.char text+= event.char print ("pressed", text) def callback(event): frame.focus_set() print ("clicked at", event.x, event.y) frame = frame(root, width=100, height=100) frame.bind("<key>", key) frame.bind("<button-1>", callback) frame.pack() root.mainloop() currently, creating text variable , everytime key() function gets called, , text stores last character typed. you can define text module level variable , , use module level text inside key function - text = '' def key(event): global text text+= event.char print("pressed", text)
Read more

android - InAppBilling registering BroadcastReceiver in AndroidManifest -

i'm implementing inapp billing in android app. works well, however, i'm trying decouple broadcast receiver activity manifest. suggestion in android's trivialdrive sample: // important: dynamically register broadcast messages updated purchases. // register receiver here instead of <receiver> in manifest // because call getpurchases() @ startup, therefore can ignore // broadcasts sent while app isn't running. // note: registering listener in activity bad idea, done here // because sample. regardless, receiver must registered after // iabhelper setup, before first call getpurchases(). currently there's class extends broadcastreceiver : public class iabbroadcastreceiver extends broadcastreceiver { /** * intent action receiver should filter for. */ public static final string action = "com.android.vending.billing.purchases_updated"; private final iabbroadcastlistener mlistener; public iabbroadcastreceiver(iabbroadcastlistener listener) { m
Read more

javascript - Z-index in d3.js -

i have map , when hover effect on region of map below yellow line , circle, last ones disappear. how can solve problem? http://jsfiddle.net/ot21n9qx/ var arc = g.append("path") .style("fill", "none") .style("stroke", "yellow") .style("stroke-width", 2) .attr("d", "m" + pathorigin[0] + "," + pathorigin[1] + " q" + svgpoint[0] + "," + pathorigin[1] + " " + svgpoint[0] + "," + svgpoint[1]); var circlesize = d3.scale.linear() .domain([0, 0.5, 1]) .range([4, 10, 4]); svg not have z order draws objects in order created. need create path , circle after create highlight regions. here forked fiddle: http://jsfiddle.net/o00fzgaf/1/
Read more