Using UISlider to change text

[rondog]

Hey Guys..just started with xcode today. I started an app using the "view-based application" template.

I got a UISlider to work. I have a maximum value of 12 and it starts at 0. When I slide it, the label above changes from 0 to 12.

My question is, as that value increases, I want to spell something out. For example, if I am at value 8 and have a string of "Hello World!!", the label would read, "Hello Wor", increasing it to 9 would give me "Hello Worl"..get it?

I am a flash and php guy so I am familiar with arrays, substrings etc. Just new to the xcode stuff. Many thanks!

[Duncan C]

Originally Posted by rondog

Hey Guys..just started with xcode today. I started an app using the "view-based application" template.

I got a UISlider to work. I have a maximum value of 12 and it starts at 0. When I slide it, the label above changes from 0 to 12.

My question is, as that value increases, I want to spell something out. For example, if I am at value 8 and have a string of "Hello World!!", the label would read, "Hello Wor", increasing it to 9 would give me "Hello Worl"..get it?

I am a flash and php guy so I am familiar with arrays, substrings etc. Just new to the xcode stuff. Many thanks!

Take a look at the XCode docs for NSString. There are quite a few methods that let you extract substrings. In your case, you probably want substringToIndex.

[devanshree.c]

Originally Posted by rondog

Hey Guys..just started with xcode today. I started an app using the "view-based application" template.

I got a UISlider to work. I have a maximum value of 12 and it starts at 0. When I slide it, the label above changes from 0 to 12.

My question is, as that value increases, I want to spell something out. For example, if I am at value 8 and have a string of "Hello World!!", the label would read, "Hello Wor", increasing it to 9 would give me "Hello Worl"..get it?

I am a flash and php guy so I am familiar with arrays, substrings etc. Just new to the xcode stuff. Many thanks!

Try to use:
- (NSString *)substringToIndexNSUInteger)to;
i hope it helps you...

[rondog]

Hey guys I appreciate the help so far. I guess I jumped the gun a little bit.

How do I even define a string??

For actionscript, its as simple as

var myString:String = "Here is my string";

or even PHP

$myString = "Here is my string";

I've googled around and I cannot find how to just define a string..

[rondog]

Here is what I have so far for my slide:

-(IBAction) sliderChanged:(id) sender {
	UISlider *slider = (UISlider *) sender;
	int progressAsInt = (int)(slider.value + 0.5f);
	NSString *newText = [[NSString alloc]
						 initWithFormat:@"%d",progressAsInt];
	self.sliderLabel.text = newText;
	[newText release];
}

That code just puts the progress (0-12) into a text field

[kelvinkao]

-(IBAction) sliderChanged:(id) sender {
	UISlider *slider = (UISlider *) sender;
	int progressAsInt = (int)(slider.value + 0.5f);
	NSString *wholeText = @"Hello world";
	NSString *newText = [wholeText substringToIndex:progressAsInt];
	self.sliderLabel.text = newText;
}

[rondog]

Originally Posted by kelvinkao

-(IBAction) sliderChanged:(id) sender {
	UISlider *slider = (UISlider *) sender;
	int progressAsInt = (int)(slider.value + 0.5f);
	NSString *wholeText = @"Hello world";
	NSString *newText = [wholeText substringToIndex:progressAsInt];
	self.sliderLabel.text = newText;
}

Excellent! So to answer my previous questions, defining a string is as simple as:

NSString *myStr = @"Here is my string"; ?

What is the significance of the '@' character?

[ChrisL]

Originally Posted by rondog

What is the significance of the '@' character?

The '@' denotes a literal NSString instance (as opposed to a C string literal).