iphone 动态显示正在刷新。

//
//  ActivityView.h
//
//  Copyright 2010. All rights reserved.
//

#import <UIKit/UIKit.h>

#define kAnimationDurationStart 2
#define kAnimationDurationEnd 1

@interface ActivityView : NSObject {
    IBOutlet UILabel *messageLabel;
    IBOutlet UIView *view;
    BOOL isShow;
}

@property (nonatomic, readonly) UILabel *messageLabel;
@property (nonatomic, readonly) UIView *view;
@property (nonatomic) BOOL isShow;

+ (ActivityView *)sharedActivityView;

- (void)showWithMessage:(NSString *)message  animate:(BOOL)animate;
- (void)hide:(BOOL)animate;

@end

//
//  ActivityView.m
//
//  Copyright 2010  All rights reserved.
//

#import "ActivityView.h"

@implementation ActivityView

@synthesize messageLabel,view, isShow;
//单例模式
static ActivityView *activityView;


- (id) init {
    self = [super init];
    if (self != nil) {
        [[NSBundle mainBundle] loadNibNamed:@"ActivityView" owner:self options:nil];
        [[[UIApplication sharedApplication] keyWindow] addSubview:view];
        [view setFrame:CGRectMake(0, [UIApplication sharedApplication].statusBarFrame.size.height-view.frame.size.height, view.frame.size.width, view.frame.size.height)];
        isShow = NO;
    }
    return self;
}

+ (ActivityView *)sharedActivityView {
    if (!activityView) {
        activityView = [[ActivityView alloc]init];
    }
    return activityView;
}

- (void)showWithMessage:(NSString *)message animate:(BOOL)animate {
    isShow = YES;
    messageLabel.text = message;
    [view.superview bringSubviewToFront:view];
    if ( animate )
    {
       
        [UIView beginAnimations:nil context:NULL];
        [UIView setAnimationDuration:kAnimationDurationStart];
        [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
        [view setFrame:CGRectMake(0, [UIApplication sharedApplication].statusBarFrame.size.height, view.frame.size.width, view.frame.size.height)];
        [UIView commitAnimations];
    }
    else
    {
        [view setFrame:CGRectMake(0, [UIApplication sharedApplication].statusBarFrame.size.height, view.frame.size.width, view.frame.size.height)];
    }


}

- (void)hide:(BOOL)animate{
    messageLabel.text = @"";
    if (animate)
    {
        [UIView beginAnimations:nil context:NULL];
        [UIView setAnimationDuration:kAnimationDurationEnd];
        [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
        [view setFrame:CGRectMake(0, [UIApplication sharedApplication].statusBarFrame.size.height-view.frame.size.height, view.frame.size.width, view.frame.size.height)];
        [UIView commitAnimations];   
    }
    else
    {
        [view setFrame:CGRectMake(0, [UIApplication sharedApplication].statusBarFrame.size.height-view.frame.size.height, view.frame.size.width, view.frame.size.height)];
    }
    [[UIApplication sharedApplication] keyWindow].userInteractionEnabled = YES;
    isShow = NO;
}   
@end
 

调用方法

 [[ActivityView sharedActivityView] showWithMessage:@"正在下载数据" animate: NO];

[[ActivityView sharedActivityView] hide: YES];

如何更改ActivityView位置，

修改 setFrame方法

coco china里有人提供了另外一个方法：

#define activityViewTag                0x98751234

@interface UIView (UIViewUtils)

- (void)showActivityViewAtCenter;
- (void)hideActivityViewAtCenter;
- (UIActivityIndicatorView*)createActivityViewAtCenter:(UIActivityIndicatorViewStyle)style;
- (UIActivityIndicatorView*)getActivityViewAtCenter;

@end

#import "UIViewUtils.h"


@implementation UIView (UIViewUtils)

- (UIActivityIndicatorView*)createActivityViewAtCenter:(UIActivityIndicatorViewStyle)style
{
    static int size = 30;
    
    UIActivityIndicatorView* activityView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:style];
    activityView.frame = CGRectMake([UIScreen mainScreen].bounds.size.width/2 - size/2, [UIScreen mainScreen].bounds.size.height/2 - size*2, size, size);
    activityView.tag = activityViewTag;
    [self addSubview:activityView];
    [activityView release];
    
    return activityView;
}

- (UIActivityIndicatorView*)getActivityViewAtCenter
{
    UIView* view = [self viewWithTag:activityViewTag];
    if (view != nil && [view isKindOfClass:[UIActivityIndicatorView class]]){
        return (UIActivityIndicatorView*)view;
    }
    else {
        return nil;
    }
}

- (void)showActivityViewAtCenter
{
    UIActivityIndicatorView* activityView = [self getActivityViewAtCenter];
    if (activityView == nil){
        activityView = [self createActivityViewAtCenter:UIActivityIndicatorViewStyleWhite];
    }

    [activityView startAnimating];
}

- (void)hideActivityViewAtCenter
{
    UIActivityIndicatorView* activityView = [self getActivityViewAtCenter];
    if (activityView != nil){
        [activityView stopAnimating];
    }        
}


@end