ios中自定义alert view，并实现动画组合

工作需要，要做一个类似于alert的view，在上面可以自己随便画东西，在网上找了一个开源的例子，读了源码之后，感觉对ios的view和动画有了更深的了解，现在与大家分享。

下面是其中自定义alertview和动画页面的主要代码，有我的注释，

//
//  CustomizedAlertViewDemoAppDelegate.m
//  CustomizedAlertViewDemo
//
//  Created by CocoaBob on 11-3-22.
//  Copyright 2011 CocoaBob. All rights reserved.
//

#import "CustomizedAlertViewDemoAppDelegate.h"

@implementation CustomizedAlertViewDemoAppDelegate

@synthesize window;

#pragma mark -
#pragma mark Application lifecycle

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    
	
    //设置显示按钮背景，stretchableImageWithLeftCapWidth:topCapHeight:设置图片的不可拉伸去，
	[mShowAlertButton setBackgroundImage:[[UIImage imageNamed:@"button_white"] stretchableImageWithLeftCapWidth:6.0 topCapHeight:6.0] forState:UIControlStateNormal];
	[mShowAlertButton setBackgroundImage:[[UIImage imageNamed:@"button_white_highlight"] stretchableImageWithLeftCapWidth:6.0 topCapHeight:6.0] forState:UIControlStateHighlighted];
	
    //设置alert的背景
	UIImageView *backgroundView = [[UIImageView alloc] initWithImage:[[UIImage imageNamed:@"alert-view-bg-portrait"] stretchableImageWithLeftCapWidth:142 topCapHeight:31]];
	[backgroundView setFrame:mAlertView.bounds];
    
    //将alert插入到背景中
	[mAlertView insertSubview:backgroundView atIndex:0];
	
	[self.window makeKeyAndVisible];
    return YES;
}

- (void)dealloc {
    [window release];
    [super dealloc];
}

#pragma mark animations

static CGFloat kTransitionDuration = 2;

- (CGAffineTransform)transformForOrientation {
	UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;
	if (orientation == UIInterfaceOrientationLandscapeLeft) {
		return CGAffineTransformMakeRotation(M_PI*1.5);
	} else if (orientation == UIInterfaceOrientationLandscapeRight) {
		return CGAffineTransformMakeRotation(M_PI/2);
	} else if (orientation == UIInterfaceOrientationPortraitUpsideDown) {
		return CGAffineTransformMakeRotation(-M_PI);
	} else {
		return CGAffineTransformIdentity;
	}
}

- (void)bounce2AnimationStopped{
	[UIView beginAnimations:nil context:nil];
	[UIView setAnimationDuration:kTransitionDuration/2];
	mAlertView.transform = [self transformForOrientation];
	[UIView commitAnimations];
}

- (void)bounce1AnimationStopped{
	[UIView beginAnimations:nil context:nil];
	[UIView setAnimationDuration:kTransitionDuration/2];
	[UIView setAnimationDelegate:self];
	[UIView setAnimationDidStopSelector:@selector(bounce2AnimationStopped)];
	mAlertView.transform = CGAffineTransformScale([self transformForOrientation], 1.5, 1.5);
	[UIView commitAnimations];
}

- (void)alertViewIsRemoved{
	[[mAlertViewSuperView retain] removeFromSuperview];
	[mTempFullscreenWindow release];
	mTempFullscreenWindow = nil;
}

#pragma mark IBAction

- (IBAction)showAlertView:(id)sender{
    //mTempFullscreenWindow对应的是alert外围的不可交互window
	if (!mTempFullscreenWindow) {
        //设置为屏幕大小
		mTempFullscreenWindow = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
        //这里是设置window的层次等级，参见UIWindowLevel
		mTempFullscreenWindow.windowLevel = UIWindowLevelStatusBar;
        //设置背景颜色，即灰色透明
		mTempFullscreenWindow.backgroundColor = [UIColor clearColor];
        //将AlertViewSuperView加入window
		[mTempFullscreenWindow addSubview:mAlertViewSuperView];
		[mAlertViewSuperView setAlpha:0.0f];
		[mAlertViewSuperView setFrame:[mTempFullscreenWindow bounds]];
		[mTempFullscreenWindow makeKeyAndVisible];
		
        //创建旋转动画
        CABasicAnimation* rotationAnimation;
        rotationAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
        rotationAnimation.toValue = [NSNumber numberWithFloat: M_PI * 2.0  ];
        rotationAnimation.duration = 0.5;
        rotationAnimation.cumulative = YES;
        rotationAnimation.repeatCount = 1;
        
        
        
        //创建转移缩放动画
		mAlertView.transform = CGAffineTransformScale([self transformForOrientation], 0.1, 0.1); 
        //开始动画，调用此函数之后，可以就绪修改animation的动画参数，可以让动画有渐变的效果，
        //beginAnimations:context:可以多次使用，来嵌套动画的显示
		[UIView beginAnimations:nil context:nil];        
		[UIView setAnimationDuration:1];
		[UIView setAnimationDelegate:self];
        //设置动画停止监听函数
		[UIView setAnimationDidStopSelector:@selector(bounce1AnimationStopped)];
        // mAlertView.transform 是衔接上面的动画，进行动画嵌套
		mAlertView.transform = CGAffineTransformScale([self transformForOrientation], 0.5, 1.5);
		[mAlertViewSuperView setAlpha:1.0f];
        
        //嵌套重新使用
        [UIView beginAnimations:nil context:nil];        
		[UIView setAnimationDuration:1];
		[UIView setAnimationDelegate:self];
        mAlertView.transform = CGAffineTransformScale([self transformForOrientation], 1, 1);
        
		[UIView commitAnimations];
        //开始旋转动画
        [mAlertView.layer addAnimation:rotationAnimation forKey:@"rotationAnimation"];
	}
}

- (IBAction)dismissAlertView:(id)sender{
	[UIView beginAnimations:nil context:nil];
	[UIView setAnimationDuration:kTransitionDuration/2];
	[UIView setAnimationDelegate:self];
	[UIView setAnimationDidStopSelector:@selector(alertViewIsRemoved)];
	[mAlertViewSuperView setAlpha:0.0f];
	[UIView commitAnimations];
}


@end

效果如下：

源码下载：http://download.youkuaiyun.com/detail/shencaifeixia1/4485964

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