NSButton, NSSlider

NSButton:

oval button, square button ,  check box

methods:

-(void)setEnabled:(BOOL)yn

-(int)state

if return NSOnState(1), the check box is on

if return NSOffState(0), the check box is off

-(void)setState:(int)aState

NSSlider:

-(void)setFloatValue:(float)x

-(float)floatValue

NSTextField:

-(NSString*)stringValue

-(void)setStringValue:(NSString*)aString

NSFormatter can convert a string into another type , and vice versa

-(NSObject*) objectValue

-(void)setObjectValue:(NSObject*)obj