Implementing toggle feature in a UIButton
I want to know how to add the toggling feature to a UIButton
, something like the user taps a unselected button the button becomes selected and stays selected till the user taps it again there by making unselected like it was before.
I was thinking of making an IBAction
which changes it from unselected to selected, how can I do that?
Heres what I tried:
-(IBAction)toggle {
//Toggle on implementation.
button.selected = YES;
button.highlighted = NO;
button.enabled = YES;
//Toggle off implementation.
if (button.highlighted == YES) {
button.selected = NO;
button.highlighted = YES;
button.enabled = NO;
}
}
Problem...
-(IBAction)toggleFav {
if (favButton == nil) {
UIImage *unselectedImage = [UIImage imageNamed:@"favUntapped.png"];
UIImage *selectedImage = [UIImage imageNamed:@"favTapped.png"];
[favButton setImage:unselectedImage forState:UIControlStateNormal];
[favButton setImage:selectedImage forState:UIControlStateSelected];
[favButton setFrame:CGRectMake(0, 0, 40, 40)];
}
if([favButton isSelected]){
//Add to menu开发者_JAVA百科.
[favButton setSelected:NO];
} else {
//Remove from menu.
[favButton setSelected:YES];
}
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
UIImage *unselectedImage = [UIImage imageNamed:@"unselected.png"];
UIImage *selectedImage = [UIImage imageNamed:@"selected.png"];
UIButton *b = [UIButton buttonWithType:UIButtonTypeCustom];
[b setBackgroundImage:unselectedImage forState:UIControlStateNormal];
[b setBackgroundImage:selectedImage forState:UIControlStateSelected];
[b addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
[b setFrame:CGRectMake(0, 0, 40, 40)];
[cell.contentView addSubview:b];
}
return cell;
}
-(void) buttonPressed:(UIButton *)sender
{
if([sender isSelected]){
//...
[sender setSelected:NO];
} else {
//...
[sender setSelected:YES];
}
}
Your toggleFav
code doesn't make much sense.
if (favButton == nil) {
checks, if favButton
is present. But if you are wiring it up with IB, it should always been there at that point. And if it wasn't how could the button call this method? So do it like this:
-(void)viewDidLoad
{
//....
UIImage *unselectedImage = [UIImage imageNamed:@"favUntapped.png"];
UIImage *selectedImage = [UIImage imageNamed:@"favTapped.png"];
[favButton setImage:unselectedImage forState:UIControlStateNormal];
[favButton setImage:selectedImage forState:UIControlStateSelected];
[favButton setFrame:CGRectMake(0, 0, 40, 40)];
//....
}
-(IBAction)toggleFav:(UIButton *)sender {
if([sender isSelected]){
//...
[sender setSelected:NO];
} else {
//...
[sender setSelected:YES];
}
}
Here you'll find an example project, with a DetaiView, that holds a Button with the 2 states.
Note: I am saving the information of what button was selected in the NSUserDefaults. You should not do that. Instead you'll want to save it in the model. But as I dont have informations on your model, I am just using NSUserDefaults.
-(void)hitButton:(UIButton*)button
{
buttonOnFlag = !buttonOnFlag;
if( buttonFlag )
[self performSelector:@selector(setHighlight:) withObject:button afterDelay:0];
}
- (void)setHighlight:(UIButton*)button
{
button.highlighted = true;
}
Use button.highlighted property
You should code like this:
-(IBAction)toggle:(id)sender {
//Toggle on implementation.
if (sender.highlighted == NO)
{
sender.selected = YES;
sender.highlighted = NO;
sender.enabled = YES;
}
//Toggle off implementation.
else{
sender.selected = NO;
sender.highlighted = YES;
sender.enabled = NO;
}
}
精彩评论