How to Prevent a warning

Hi i keep getting this warning when i try to build th project

warning: conditional expression of distinct Objective-C types 'UIImage*' and 'UIButton*' lacks a cast

is there any thing i can do about it?

#import "avTouchController.h"
#include "CALevelMeter.h"

// amount to skip on rewind or fast forward
#define SKIP_TIME 1.0           
// amount to play between skips
#define SKIP_INTERVAL .2

@implementation avTouchController

@synthesize fileName;
@synthesize playButton;
@synthesize ffwButton;
@synthesize rewButton;
@synthesize volumeSlider;
@synthesize progressBar;
@synthesize currentTime;
@synthesize duration;
@synthesize lvlMeter_in;

@synthesize updateTimer;
@synthesize player;

@synthesize inBackground;


void RouteChangeListener(   void *                  inClientData,
                        AudioSessionPropertyID  inID,
                        UInt32                  inDataSize,
                        const void *            inData);

-(void)updateCurrentTimeForPlayer:(AVAudioPlayer *)p
{
currentTime.text = [NSString stringWithFormat:@"%d:%02d", (int)p.currentTime / 60,     (int)p.currentTime % 60, nil];
progressBar.value = p.currentTime;
}

- (void)updateCurrentTime
{
[self updateCurrentTimeForPlayer:self.player];
}

- (void)updateViewForPlayerState:(AVAudioPlayer *)p
{
[self updateCurrentTimeForPlayer:p];

if (updateTimer) 
    [updateTimer invalidate];

if (p.playing)
{
    [playButton setImage:((p.playing == YES) ? pauseBtnBG : playBtnBG)   forState:UIControlStateNormal];
    [lvlMeter_in setPlayer:p];
    updateTimer = [NSTimer scheduledTimerWithTimeInterval:.01 target:self   selector:@selector(updateCurrentTime) userInfo:p repeats:YES];
}
else
{
    [playButton setImage:((p.playing == YES) ? pauseBtnBG : playBtnBG)   forState:UIControlStateNormal];
    [lvlMeter_in setPlayer:nil];
    updateTimer = nil;
}

}

- (void)updateViewForPlayerStateInBackground:(AVAudioPlayer *)p
{
[self updateCurrentTimeForPlayer:p];

if (p.playing)
{
    [playButton setImage:((p.playing == YES) ? rewButton : playBtnBG)  forState:UIControlStateNormal];         (this is where i have problems)
}
else
{
    [playButton setImage:((p.playing == YES) ? rewButton : playBtnBG) forState:UIControlStateNormal];
}   
}

-(void)updateViewForPlayerInfo:(AVAudioPlayer*)p
{
duration.text = [NSString stringWithFormat:@"%d:%02d", (int)p.duration / 60,   (int)p.duration % 60, nil];
progressBar.maximumValue = p.duration;
volumeSlider.value = p.volume;
}

- (void)rewind
{
AVAudioPlayer *p = rewTimer.userInfo;
p.currentTime-= SKIP_TIME;
[self updateCurrentTimeForPlayer:p];
}

- (void)ffwd
{
AVAudioPlayer *p = ffwTimer.userInfo;
p.currentTime+= SKIP_TIME;  
[self updateCurrentTimeForPlayer:p];
}

- (void)awakeFromNib
{
// Make the array to store our AVAudioPlayer objects
soundFiles = [[NSMutableArray alloc] initWithCapacity:3];

playBtnBG = [[UIImage imageNamed:@"play.png"] retain];
pauseBtnBG = [[UIImage imageNamed:@"pause.png"] retain];
rewButton = [[UIImage imageNamed:@"rewind.png"] retain];

[playButton setImage:playBtnBG forState:UIControlStateNormal];

[self registerForBackgroundNotifications];

updateTimer = nil;
rewTimer = nil;
ffwTimer = nil;

duration.adjustsFontSizeToFitWidth = YES;
currentTime.adjustsFontSizeToFitWidth = YES;
progressBar.minimumValue = 0.0; 

// Load the array with the sample file
NSURL *fileURL = [[NSURL alloc] initFileURLWithPath: [[NSBundle mainBundle]  pathForResource:@"My Song" ofType:@"mp3"]];

self.player = [[AVAudioPlayer alloc] initWithContentsOfURL:fileURL error:nil];  
if (self.player)
{
    fileName.text = [NSString stringWithFormat: @"%@ (%d ch.)", [[player.url relativePath] lastPathComponent], player.numberOfChannels, nil];
    [self updateViewForPlayerInfo:player];
    [self updateViewForPlayerState:player];
    player.numberOfLoops = 0;
    player.delegate = self;
}

OSStatus result = AudioSessionInitialize(NULL, NULL, NULL, NULL);
if (result)
    NSLog(@"Error initializing audio session! %d", result);

[[AVAudioSession sharedInstance] setDelegate: self];
NSError *setCategoryError = nil;
[[AVAudioSession sharedInstance] setCategory: AVAudioSessionCategoryPlayback error: &setCategoryError];
if (setCategoryError)
    NSLog(@"Error setting category! %d", setCategoryError);

result = AudioSessionAddPropertyListener (kAudioSessionProperty_AudioRouteChange, RouteChangeListener, self);
if (result) 
    NSLog(@"Could not add property listener! %d", result);

[fileURL release];
}

-(void)pausePlaybackForPlayer:(AVAudioPlayer*)p
{
[p pause];
[self updateViewForPlayerState:p];
}

-(void)startPlaybackForPlayer:(AVAudioPlayer*)p
{
if ([p play])
{
    [self updateViewForPlayerState:p];
}
else
    NSLog(@"Could not play %@\n", p.url);
}

- (IBAction)playButtonPressed:(UIButton *)sender
{
if (player.playing == YES)
    [self pausePlaybackForPlayer: player];
else
    [self startPlaybackForPlayer: player];
}

- (IBAction)rewButtonPressed:(UIButton *)sender
{
if (rewTimer) [rewTimer invalidate];
rewTimer = [NSTimer scheduledTimerWithTimeInterval:SKIP_INTERVAL target:self selector:@selector(rewind) userInfo:player repeats:YES];
}

- (IBAction)rewButtonReleased:(UIButton *)sender
{
if (rewTimer) [rewTimer invalidate];
rewTimer = nil;
}

- (IBAction)ffwButtonPressed:(UIButton *)sender
{
if (ffwTimer) [ffwTimer invalidate];
ffwTimer = [NSTimer scheduledTimerWithTimeInterval:SKIP_INTERVAL target:self selector:@selector(ffwd) userInfo:player repeats:YES];
}

- (IBAction)ffwButtonReleased:(UIButton *)sender
{
if (ffwTimer) [ffwTimer invalidate];
ffwTimer = nil;
}

开发者_如何学Python- (IBAction)volumeSliderMoved:(UISlider *)sender
{
player.volume = [sender value];
}

- (IBAction)progressSliderMoved:(UISlider *)sender
{
player.currentTime = sender.value;
[self updateCurrentTimeForPlayer:player];
}

- (void)dealloc
{
[super dealloc];

[fileName release];
[playButton release];
[ffwButton release];
[rewButton release];
[volumeSlider release];
[progressBar release];
[currentTime release];
[duration release];
[lvlMeter_in release];

[updateTimer release];
[player release];

[playBtnBG release];
[pauseBtnBG release];   
}

#pragma mark AudioSession handlers

void RouteChangeListener(   void *                  inClientData,
                        AudioSessionPropertyID  inID,
                        UInt32                  inDataSize,
                        const void *            inData)
{
avTouchController* This = (avTouchController*)inClientData;

if (inID == kAudioSessionProperty_AudioRouteChange) {

    CFDictionaryRef routeDict = (CFDictionaryRef)inData;
    NSNumber* reasonValue = (NSNumber*)CFDictionaryGetValue(routeDict, CFSTR(kAudioSession_AudioRouteChangeKey_Reason));

    int reason = [reasonValue intValue];

    if (reason == kAudioSessionRouteChangeReason_OldDeviceUnavailable) {

        [This pausePlaybackForPlayer:This.player];
    }
}
}

#pragma mark AVAudioPlayer delegate methods

- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)p successfully:(BOOL)flag
{
if (flag == NO)
    NSLog(@"Playback finished unsuccessfully");

[p setCurrentTime:0.];
[self updateViewForPlayerState:p];
}

- (void)playerDecodeErrorDidOccur:(AVAudioPlayer *)p error:(NSError *)error
{
NSLog(@"ERROR IN DECODE: %@\n", error); 
}

// we will only get these notifications if playback was interrupted
- (void)audioPlayerBeginInterruption:(AVAudioPlayer *)p
{
NSLog(@"Interruption begin. Updating UI for new state");
// the object has already been paused,  we just need to update UI
if (inBackground)
{
    [self updateViewForPlayerStateInBackground:p];
}
else
{
    [self updateViewForPlayerState:p];
}
}

- (void)audioPlayerEndInterruption:(AVAudioPlayer *)p
{
NSLog(@"Interruption ended. Resuming playback");
[self startPlaybackForPlayer:p];
}

#pragma mark background notifications
- (void)registerForBackgroundNotifications
{
[[NSNotificationCenter defaultCenter] addObserver:self
                                           selector:@selector(setInBackgroundFlag)
                                              name:UIApplicationWillResignActiveNotification
                                            object:nil];

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(clearInBackgroundFlag)
                                             name:UIApplicationWillEnterForegroundNotification
                                           object:nil];
}

- (void)setInBackgroundFlag
{
inBackground = true;
}

- (void)clearInBackgroundFlag
{
inBackground = false;
}

@end

EDIT: I have already tried RewBtnBG but it says not declared in this scope. Any thing to fix that?

    [playButton setImage:((p.playing == YES) ? rewButton : playBtnBG)  forState:UIControlStateNormal];

newButton is a UIButton and playBtnBG is a UIImage I guess. Possibly you really wanted (guesssing from your naming conventions for other images).

    [playButton setImage:((p.playing == YES) ? rewBtnBG : playBtnBG)  forState:UIControlStateNormal];