Image comparision is not working in ios simulator - iphone

Question

I am developing one application.In that i am doing comparision operation for two images like below
UIImage *actual_image=usrcheck_image.image;
NSData *present_image = UIImagePNGRepresentation(actual_image);
NSData *compare_image = UIImagePNGRepresentation([UIImage imageNamed:#"unchk-1.png"]);
if([present_image isEqualToData:compare_image])
{
set the checked image
}
else
{
set the uncheck image.
}
If i run this,check image is changed to uncheck.But uncheck image is not chneged to check image.Everytime else block is executed.So please help me how to compare these two images.This code is working perfectly in device.But the problem is in simulator only.

Answer 1

Try This Code -
Take 2 images of checked and unchecked and assign that images to UIButton.
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
button.frame = CGRectMake(0, 0, 160, 30);
[button setImage:[UIImage imageNamed:#"checkedImage.png"] forState:UIControlStateNormal];
[button setImage:[UIImage imageNamed:#"uncheckedImage.png"] forState:UIControlStateSelected];
button.tag = 1;
[button addTarget:self action:#selector(buttonAction:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:button];
And In buttonAction function -
selectedBtn.selected = NO;
button.selected = YES;
selectedBtn = button;
In .h file just mention
UIButton *selectedBtn;
Hope It may help you.

Answer 2

You can use highlighted property of UIImageView. Set the checked image as highlightedImage property, and on the click event set:
yourImageView.isHighlighed = !yourImageView.isHighlighed;
it will automatically show your image as toggle

Answer 3

May be link below can help you
Objective-C: Comparing an image against another image that has been previously saved
Let me know if this works

Answer 4

First thing is, there is no need of comparison of image Data and no need to compare images too,
But if you want to compare images means , just simply do like following
if(usrcheck_image.image==[UIImage imageNamed:#"unchk-1.png"]) {
usrcheck_image.image=[UIImage imageNamed:#"chk-1.png"];
} else {
usrcheck_image.image=[UIImage imageNamed:#"unchk-1.png"];
}