原文地址http://www.189works.com/article-89289-1.html

MBProgressHUD 下载地址是： http://github.com/matej/MBProgressHUD

这里介绍一下网友开源的MBProgressHUD类，实现等待框，

一、网上下载  MBProgessHUD 类文件，直接导入到工程即可

二、示例分析

在我的工程中示例如下：

1）在ShowImageViewController.h头文件代码如下：

#import <UIKit/UIKit.h>

#import "MBProgressHUD.h"

@interface ShowImageViewController : UIViewController <MBProgressHUDDelegate>{

    NSString         *_picUrlString;

    UIImageView      *_imageView;

    MBProgressHUD    *_progressHUD; 

}

@property (nonatomic, copy) NSString           *picUrlString;

@property (nonatomic, retain) IBOutlet         UIImageView *imageView;

@property (nonatomic, retain) MBProgressHUD    *progressHUD;

//请求图片资源

-(void)imageResourceRequest;

//显示图片信息

-(void)displayImage:(UIImage *)image;

- (IBAction)dismissModealView:(id)sender;

-(void)removeModalView;

@end

2）在ShowImageViewController.m实现文件代码如下：

#import "ShowImageViewController.h"

#import <QuartzCore/QuartzCore.h>

@implementation ShowImageViewController

@synthesize picUrlString = _picUrlString;

@synthesize imageView = _imageView;

@synthesize progressHUD = _progressHUD;

- (void)viewDidLoad

{

    [super viewDidLoad];

    // Do any additional setup after loading the view from its nib.

    self.view.backgroundColor = [UIColor grayColor];

    self.view.alpha = 0.8;

    //设置图片为圆角

    self.imageView.backgroundColor = [UIColor clearColor];

    self.imageView.layer.borderColor = [UIColor lightGrayColor].CGColor;

    self.imageView.layer.borderWidth = 5.0;

    self.imageView.layer.masksToBounds = YES; 

    self.imageView.layer.cornerRadius = 10.0; 

}

-(void)viewWillAppear:(BOOL)animated

{

    [super viewWillAppear:animated];

    //当进入视图时，重新设置imageView

    [self.imageView setImage:nil];

    [self.imageView setFrame:CGRectMake(160, 200, 0, 0)];

    //显示加载等待框

    self.progressHUD = [[MBProgressHUD alloc] initWithView:self.view];

    [self.view addSubview:self.progressHUD];

    [self.view bringSubviewToFront:self.progressHUD];

    self.progressHUD.delegate = self;

    self.progressHUD.labelText = @"加载中...";

    [self.progressHUD show:YES];

    //开启线程，请求图片资源

    [NSThread detachNewThreadSelector:@selector(imageResourceRequest) toTarget:selfwithObject:nil];

}

//请求图片资源

-(void)imageResourceRequest

{

    NSAutoreleasePool   *pool = [[NSAutoreleasePool alloc] init];

    //根据网络数据，获得到image资源

    NSData  *data = http://www.cnblogs.com/snake-hand/archive/2012/08/13/[[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:self.picUrlString]];

    UIImage *image = [[UIImage alloc] initWithData:data];

    [data release];

    //回到主线程，显示图片信息

    [self performSelectorOnMainThread:@selector(displayImage:) withObject:imagewaitUntilDone:NO];

    [image release];

    [pool release];

}

//显示图片信息

-(void)displayImage:(UIImage *)image

{

    //若self.progressHUD为真，则将self.progressHUD移除，设为nil

    if (self.progressHUD){

        [self.progressHUD removeFromSuperview];

        [self.progressHUD release];

        self.progressHUD = nil;

    }

    //图片慢慢放大动画效果

    [self.imageView setImage:image];

    [UIView beginAnimations:nil context:nil];

    [UIView setAnimationDuration:0.5];

    [self.imageView setFrame:CGRectMake(40, 100, 240, 160)];

    [UIView commitAnimations];

}

- (void)viewDidUnload

{

    [self setImageView:nil];

    [super viewDidUnload];

    // Release any retained subviews of the main view.

    // e.g. self.myOutlet = nil;

}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation

{

    // Return YES for supported orientations

    return (interfaceOrientation == UIInterfaceOrientationPortrait);

}

- (IBAction)dismissModealView:(id)sender {   

    //设置定时器，当动画结束时，子视图从父视图中移除

    [NSTimer scheduledTimerWithTimeInterval:0.5 target:selfselector:@selector(removeModalView) userInfo:nil repeats:NO];

    [UIView beginAnimations:nil context:nil];

    [UIView setAnimationDuration:0.5];

    [self.imageView setFrame:CGRectMake(160, 200, 0, 0)];

    [UIView commitAnimations];

}

-(void)removeModalView

{

    [self.view removeFromSuperview];

}

#pragma mark -

#pragma mark MBProgressHUDDelegate methods

- (void)hudWasHidden:(MBProgressHUD *)hud {

    NSLog(@"Hud: %@", hud);

    // Remove HUD from screen when the HUD was hidded

    [self.progressHUD removeFromSuperview];

    [self.progressHUD release];

    self.progressHUD = nil;

}

- (void)dealloc

{

    [_picUrlString release];

    [_imageView release];

    [super dealloc];

}

@end

四、总结

利用MBProgressHUD实现加载等待框，视觉效果大大提高