In my Application am trying to display an image in a rectangle and am using DrawRect method.The problem is at the output am seeing nothing.Only blank screen in simulator.Here is the code:
- (void)viewDidLoad {
[super viewDidLoad];
[self drawRect:CGRectMake(78, 43, 222, 138)];
}
- (void)drawRect:(CGRect)rect {
UIImage *myImage = [UIImage imageNamed:#"btbp.jpg"];
CGRect imageRect = CGRectMake(10, 10, 300, 400);
[myImage drawInRect:imageRect];
//[self setNeedsDisplay];
[myImage release];
}
there is no effect in invoking drawRect. instead you should invoke setNeedsDisplay to enforce redrawing.
Related
who can help me with this code? Simply it doesn't work, same as ALL I have tried for vertical scrolling. I'm starting to think that my Xcode emulator has something wrong. Here's the code:
#interface ViewController ()
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
UIScrollView *scroll = [[UIScrollView alloc] initWithFrame:CGRectMake(10, 30, 300, 400)];
[self.view addSubview:scroll];
[scroll setBackgroundColor:[UIColor redColor]];
{
UIImageView *imageview = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 1222, 400)];
[imageview setImage:[UIImage imageNamed:#"panorama_orizzonte_medio_big.jpg"]];
[scroll addSubview:imageview];
[self.view addSubview:scroll];
}
// Do any additional setup after loading the view, typically from a nib.
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#end
After you set the UIImageView, you need to set the scrollView's contentSize to that of your imageView's, so, something like this:
[scroll setContentSize:imageview.frame.size];
I just want to make an UIImageView programmatically that displays a 20by20 dot at point (50,50).(The image of the dot is called draw.png). For some reason nothing shows up on the screen.
Heres my code:
- (void)viewDidLoad
{
UIImageView *dot =[[UIImageView alloc] initWithFrame:CGRectMake(50,50,20,20)];
dot.image=[UIImage imageNamed:#"draw.png"];
[self.view addSubview:dot];
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib
}
First, make sure draw.png exists in your project and that you are referencing it exactly (so if it's draw.PNG you should put #"draw.PNG"). Also, call [super viewDidLoad] before everything.
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib
UIImageView *dot =[[UIImageView alloc] initWithFrame:CGRectMake(50,50,20,20)];
dot.image=[UIImage imageNamed:#"draw.png"];
[self.view addSubview:dot];
}
Try this :-
UIImageView *imageview = [[UIImageView alloc]
initWithFrame:CGRectMake(50, 50, 20, 20)];
[imageview setImage:[UIImage imageNamed:#"AppleUSA1.jpg"]];
[imageview setContentMode:UIViewContentModeScaleAspectFit];
[self.view addSubview:imageview];
In Swift :
let imageView = UIImageView(frame: CGRect(x: 50, y: 50, width: 20, height: 20))
imageView.image = UIImage(named: "draw.png")
self.view.addSubview(imageView)
This code is correct. Make sure draw.png exists in your project. You can do it by checking if [UIImage imageNamed:#"draw.png"] doesn't return nil.
Also, make sure you don't have another view on top of your image view.
make sure that image is in your project..
UIImageView *imgView=[[UIImageView alloc]initWithFrame:CGRectMake(100, 100, 50, 50)];
[imgView setImage:[UIImage imageNamed:#"xyz.jpg"]];//if your images extension is .png than no need to write extension of an image..
[self.view addSubview:imgView];
This code is perfect match an UIImageView:
UIImageView *IMG_view= [[UIImageView alloc] initWithFrame:CGRectMake(20 ,50 ,40 ,40)];
[IMG_view setTag:100]; //[IMG_view setTag:indexPath.row];
IMG_view.layer.borderWidth= 0.5 ;
IMG_view.layer.borderColor= [[UIColor clearColor] CGColor];
IMG_view.layer.cornerRadius= 3;
IMG_view.contentMode = UIViewContentModeScaleAspectFit;
[self.view addSubview:IMG_view];
IMG_view.image=[UIImage imageNamed:#"Loading_50x50.png"];
I'm working on a Mac application with an NSScrollView, and I want the NSScrollView to have a custom background image. I used this code in the custom documentView NSView subclass:
- (void)drawRect:(NSRect)rect {
[[NSColor colorWithPatternImage:[NSImage imageNamed:#"wood.jpg"]] set];
NSRectFill(rect);
}
That displays a pattern image as a background for the documentView.
But now in Mac OS X Lion, the NSScrollView bounces when scrolling further than possible, showing ugly white space. How can I make the white space also being covered by the background image?
Instead of overriding drawRect:, use the scroll view's setBackgroundColor: method, passing the NSColor you created with the pattern image.
You should subclass use NSScrollView setBackgroundColor, but then you should subclass NSClipView like this to pin the texture origin to the top:
#implementation MYClipView
- (id)initWithFrame:(NSRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code here.
}
return self;
}
- (void)drawRect:(NSRect)dirtyRect
{
if (self.drawsBackground)
{
NSGraphicsContext* theContext = [NSGraphicsContext currentContext];
[theContext saveGraphicsState];
float xOffset = NSMinX([self convertRect:[self frame] toView:nil]);
float yOffset = NSMaxY([self convertRect:[self frame] toView:nil]);
[theContext setPatternPhase:NSMakePoint(xOffset, yOffset)];
NSColor* color = self.backgroundColor;
[color set];
NSRectFill([self bounds]);
[theContext restoreGraphicsState];
}
// Note: We don't call [super drawRect:dirtyRect] because we don't need it to draw over our background.
}
+ (void)replaceClipViewInScrollView:(NSScrollView*)scrollView
{
NSView* docView = [scrollView documentView]; //[[scrollView documentView] retain];
MYClipView* newClipView = nil;
newClipView = [[[self class] alloc] initWithFrame:[[scrollView contentView] frame]];
[newClipView setBackgroundColor:[[scrollView contentView] backgroundColor]];
[scrollView setContentView:(NSClipView*)newClipView]; [scrollView setDocumentView:docView];
// [newClipView release];
// [docView release];
}
#end
And call + (void)replaceClipViewInScrollView:(NSScrollView*)scrollView with the NSScrollView instance.
Put your drawRect code in an NSScrollView subclass. In IB, change the NSScrollView to use your custom subclass instead of NSScrollView. Also make sure to uncheck Draw Background in the scroll view's attributes inspector.
I would like to make an infinite scrolling view for iPad. The scrolling works, only when I add pictures to my customized scrollview class, it appears out of the view's frame too (so I have view, which has a UIScrollView on it. This scroll view is connected with my CustomScroll.h :UIScrollView and CustomScroll.m files). Why do the images appear outside the view's frame (the view's frame is set in nib file to 320x420)?
CustomScroll.h:UIScrollView
A part from CustomScroll.m file:
- (id)initWithCoder:(NSCoder *)aDecoder{
if ((self = [super initWithCoder:aDecoder])){
self.contentSize = CGSizeMake(2000, 416);
[self setShowsVerticalScrollIndicator:NO];
for (int i=1; i<=4; i++){
[self addImageAtPosition:i];
}
//todo: to replace with the method: addFirstElementToTheEnd
UIImageView *image1 = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"image1.jpg"]];
[image1 setFrame:CGRectMake(5*320, 0, 320, 416)];
[self addSubview:image1];
[image1 release];
//todo: to replace with the method: addLastElementToTheBeginning
UIImageView *image2 = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"image4.jpg"]];
[image2 setFrame:CGRectMake(0*320, 0, 320, 416)];
[self addSubview:image2];
[image2 release];
}
return self;
}
- (void)addImageAtPosition:(NSInteger)position{
UIImageView *tempImage = [[UIImageView alloc] initWithImage:[UIImage imageNamed:[NSString stringWithFormat:#"image%d.jpg", position]]];
[tempImage setFrame:CGRectMake((position * 320), 0, 320, 416)];
[self addSubview:tempImage];
[tempImage release];
}
- (void)recenterIfNecessary{
CGFloat currentOffsetX = [self contentOffset].x;
if (currentOffsetX > 1600.00){
self.contentOffset = CGPointMake(320, [self contentOffset].y );
}
if (currentOffsetX < 320.00){
self.contentOffset = CGPointMake(5*320, [self contentOffset].y);
}
}
- (void) layoutSubviews{
[super layoutSubviews];
[self recenterIfNecessary];
}
TY.
I am launching detail pages from a UITableView and within that detail page there is an image. I would like it to be zoomable, so I'd like the contents of that detail page to sit inside a scrollView. So far no luck, the labels, textviews and images are fine, but I can't get the ScrollView implemented.
here is my .m: THANKS!
- (void)viewDidLoad {
UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];
scrollView.contentSize = CGSizeMake(320, 700);
scrollView.clipsToBounds = YES;
super.view.backgroundColor = [UIColor whiteColor];
[scrollView setUserInteractionEnabled:YES];
self.navigationItem.title = [NSString stringWithFormat:selectedCellItem];
CGRect frame = CGRectMake(0, 0, 10, 10);
self.view = [[UIView alloc] initWithFrame:frame];
self.view.backgroundColor = [UIColor whiteColor];
frame = CGRectMake(0, 320, 10, 10);
UILabel *label = [[UILabel alloc] initWithFrame:frame];
//label.text = selectedCellItem;
label.font=[UIFont fontWithName:#"Verdana-Bold" size:20.0];
label.textAlignment = UITextAlignmentCenter;
[self.view addSubview:label];
[label release];
frame = CGRectMake(0, 320, 320, 60); //Description
UITextView *labelDesc = [[UITextView alloc] initWithFrame:frame];
labelDesc.text = selectedCellDesc;
labelDesc.font=[UIFont fontWithName:#"Verdana" size:12.0];
labelDesc.textAlignment = UITextAlignmentLeft;
//labelDesc.textAlignment = UITextAlignmentTop;
[self.view addSubview:labelDesc];
[labelDesc release];
frame = CGRectMake(0, 0, 320, 320); //Image
UIImageView *imageItem = [[UIImageView alloc] initWithFrame:frame];
[imageItem setImage:[UIImage imageNamed:selectedCellImage]];
// GET THIS ONE WORKING RIGHT>>[imageItem setImage:[UIImage imageNamed:[NSString stringWithFormat:#"%#.png", [[NSBundle mainBundle] bundlePath], selectedCellImage]]]; //use
//imageItem = [[UIImageView alloc] initWithContentsOfFile:[NSString stringWithFormat:#"shirt.png", [[NSBundle mainBundle] bundlePath]]];
//labelDesc.font=[UIFont fontWithName:#"Zapfino" size:13.0];
//labelDesc.textAlignment = UITextAlignmentCenter;
imageItem.contentMode = UIViewContentModeScaleAspectFit;
[self.view addSubview:imageItem];
//[imageItem release];
[super viewDidLoad];
}
/*
// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
*/
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
- (void)viewDidUnload {
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)dealloc {
[super dealloc];
}
#end
I think that you're missing the following line to add the UIScrollView as a subview.
[self.view addSubView:scrollView];