ipad 视频播放器的渐变播放效果
实现视频播放的渐变切换效果，可以修改代码在iphone上使用。

////  FLWPlayer.m////  Created by scott.8an@gmail.com on 11-10-28.//  Copyright 2011 littleWorn inc. All rights reserved.//#import "FLWPlayer.h"@implementation FLWPlayer@synthesize delegate = _delegate;@synthesize url = _url;@synthesize player = _player;#pragma mark life cycle- (void)dealloc {[_delegate release];[_url release];[_player release];    [super dealloc];}//init-(id)init{if (self = [super init]) {//去掉状态栏[[UIApplication sharedApplication] setStatusBarHidden:YES];UITapGestureRecognizer *tg = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(singleTap)];tg.numberOfTapsRequired = 2;[self addGestureRecognizer:tg];[tg release];}return self;}-(id)initWithFrame:(CGRect)frame{if (self = [super initWithFrame:frame]) {//去掉状态栏[[UIApplication sharedApplication] setStatusBarHidden:YES];UITapGestureRecognizer *tg = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(singleTap)];tg.numberOfTapsRequired = 2;[self addGestureRecognizer:tg];[tg release];}return self;}-(id)initWithURL:(NSURL*)url{if (self = [super init]) {self.url = url;//去掉状态栏[[UIApplication sharedApplication] setStatusBarHidden:YES];UITapGestureRecognizer *tg = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(singleTap)];tg.numberOfTapsRequired = 2;[self addGestureRecognizer:tg];[tg release];}return self;}-(id)initWithFrame:(CGRect)frame url:(NSURL*)url{if (self = [super initWithFrame:frame]) {self.url = url;//去掉状态栏[[UIApplication sharedApplication] setStatusBarHidden:YES];UITapGestureRecognizer *tg = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(singleTap)];tg.numberOfTapsRequired = 2;[self addGestureRecognizer:tg];[tg release];}return self;}-(void)singleTap{[self.delegate singleTapView:self];}#pragma mark overide//-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{//[self.delegate singleTapView:self];//}//播放视频-(void)play{//覆盖UIView *cover = [[UIView alloc] initWithFrame:CGRectMake(0,0, 1024, 768)];cover.tag = 100;cover.backgroundColor = [UIColor blackColor];cover.alpha = 0.0f;//添加覆盖视图实现渐变退出效果[UIView beginAnimations:nil context:nil];[UIView setAnimationDuration:0.4f];[UIView setAnimationDelay:0.2f];[UIView setAnimationDelegate:self];[UIView setAnimationDidStopSelector:@selector(stopPlaying)];cover.alpha = 1.0f;[UIView commitAnimations];[self addSubview:cover];[cover release];self.backgroundColor = [UIColor blackColor];}//开始播放-(void)startToPlay{if (nil == self.url) {return;}//清除覆盖UIView *cover = [self viewWithTag:100];if (cover) {[cover removeFromSuperview];}//加载视频if (_player) {[_player setContentURL:self.url];}else {self.player = [[MPMoviePlayerController alloc] initWithContentURL:self.url];_player.view.frame = CGRectMake(0, 0, 1024, 768);_player.controlStyle= MPMovieControlStyleNone;_player.repeatMode = MPMovieRepeatModeOne;[_player setFullscreen:YES];[self addSubview:_player.view];[_player release];}//开始播放[_player prepareToPlay];[_player play];//渐变进入_player.view.alpha = 0.0f;_player.backgroundView.backgroundColor = [UIColor blackColor];[UIView beginAnimations:nil context:nil];[UIView setAnimationDuration:1.0f];_player.view.alpha = 1.0f;[UIView commitAnimations];}//停止正在播放的视频-(void)stopPlaying{[self stop];[self startToPlay];}//停止播放-(void)stop{if (_player) {[_player stop];}}//暂停播放-(void)pause{if (_player) {[_player pause];}}@end