最终效果图
使用了一个自定义uiview，里面加入了一个progressbar和两个label，
头文件
#import <UIKit/UIKit.h>
@protocol UIDownloadBarDelegate;
@interface UIDownloadBar : UIView {
UIProgressView *progressView;
NSURLRequest* DownloadRequest;
NSURLConnection* DownloadConnection;
NSMutableData* receivedData;
NSString* localFilename;
id<UIDownloadBarDelegate> delegate;
long long bytesReceived;
long long expectedBytes;
float percentComplete;
UILabel *lblDownloadBytes;
UILabel *lblDownloadPercent;
}
@property （nonatomic, readonly） NSMutableData* receivedData;
@property （nonatomic, readonly, retain） NSURLRequest* DownloadRequest;
@property （nonatomic, readonly, retain） NSURLConnection* DownloadConnection;
@property （nonatomic, assign） id<UIDownloadBarDelegate> delegate;
@property （nonatomic, readonly） float percentComplete;
- （UIDownloadBar *）initWithURL:（NSURL *）fileURL
progressBarFrame:（CGRect）frame
timeout:（NSInteger）timeout
delegate:（id<UIDownloadBarDelegate>）theDelegate;
@end
@protocol UIDownloadBarDelegate<NSObject>
@optional
- （void）downloadBar:（UIDownloadBar *）downloadBar didFinishWithData:（NSData *）fileData suggestedFilename:（NSString *）filename;
- （void）downloadBar:（UIDownloadBar *）downloadBar didFailWithError:（NSError *）error;
- （void）downloadBarUpdated:（UIDownloadBar *）downloadBar;
@end
实现类
#import "UIDownloadBar.h"
#import <QuartzCore/QuartzCore.h>
@implementation UIDownloadBar
@synthesize DownloadRequest,DownloadConnection,receivedData,delegate,percentComplete;
- （UIDownloadBar *）initWithURL:（NSURL *）fileURL progressBarFrame:（CGRect）frame timeout:（NSInteger）timeout delegate:（id<UIDownloadBarDelegate>）theDelegate {
self = [super initWithFrame:frame];
if（self） {
self.layer.borderWidth = 2.0;
self.layer.cornerRadius = 5.0;
self.layer.borderColor = [UIColor whiteColor].CGColor;
self.backgroundColor = [UIColor blackColor];
//进度条，中间
progressView = [[UIProgressView alloc]initWithProgressViewStyle:UIProgressViewStyleBar];
progressView.frame = CGRectMake（10, 20, self.frame.size.width-20, 20）；
[self addSubview:progressView];
//左下角
CGRect lblDownloadBytesFrame = CGRectMake（10, frame.size.height-35, 120, 20）；
lblDownloadBytes = [[UILabel alloc]initWithFrame:lblDownloadBytesFrame];
lblDownloadBytes.textColor = [UIColor whiteColor];
lblDownloadBytes.backgroundColor = [UIColor clearColor];
[self addSubview:lblDownloadBytes];
//右下角
CGRect lblDownloadPercentFrame = CGRectMake（frame.size.width-50
, frame.size.height-35, 60, 20）；
lblDownloadPercent = [[UILabel alloc]initWithFrame:lblDownloadPercentFrame];
lblDownloadPercent.textColor = [UIColor whiteColor];
lblDownloadPercent.backgroundColor = [UIColor clearColor];
[self addSubview:lblDownloadPercent];
self.delegate = theDelegate;
lblDownloadPercent.text = @"0%";
bytesReceived = percentComplete = 0;
localFilename = [[[fileURL absoluteString] lastPathComponent] copy];
receivedData = [[NSMutableData alloc] initWithLength:0];
progressView.progress = 0.0;
progressView.backgroundColor = [UIColor clearColor];
DownloadRequest = [[NSURLRequest alloc] initWithURL:fileURL cachePolicy:NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:timeout];
DownloadConnection = [[NSURLConnection alloc] initWithRequest:DownloadRequest delegate:self startImmediately:YES];
if（DownloadConnection == nil） {
[self.delegate downloadBar:self didFailWithError:[NSError errorWithDomain:@"UIDownloadBar Error" code:1 userInfo:[NSDictionary dictionaryWithObjectsAndKeys:@"NSURLConnection Failed", NSLocalizedDescriptionKey, nil]]];
}
}
return self;
}
- （void）connection:（NSURLConnection *）connection didReceiveData:（NSData *）data {
[self.receivedData appendData:data];
NSInteger receivedLen = [data length];
bytesReceived = （bytesReceived + receivedLen）；
lblDownloadBytes.text = [NSString stringWithFormat:@"%.02f/%.02fMB",
（float）bytesReceived/1048576,（float）expectedBytes/1048576];
//百分比
lblDownloadPercent.text = [NSString stringWithFormat:@"%.0f%%",
（（（float）bytesReceived/1048576）/（（float）expectedBytes/1048576））*100];
if（expectedBytes != NSURLResponseUnknownLength） {
progressView.progress = （（bytesReceived/（float）expectedBytes）*100）/100;
percentComplete = progressView.progress*100;
}
[delegate downloadBarUpdated:self];
}
- （void）connection:（NSURLConnection *）connection didFailWithError:（NSError *）error {
[self.delegate downloadBar:self didFailWithError:error];
[connection release];
}
- （void）connection:（NSURLConnection *）connection didReceiveResponse:（NSURLResponse *）response {
expectedBytes = [response expectedContentLength];
lblDownloadBytes.text = [NSString stringWithFormat:@"0/%.02fMB",（float）expectedBytes/1048576];
}
- （void）connectionDidFinishLoading:（NSURLConnection *）connection {
[self.delegate downloadBar:self didFinishWithData:self.receivedData suggestedFilename:localFilename];
[connection release];
}
- （void）drawRect:（CGRect）rect {
[super drawRect:rect];
}
- （void）dealloc {
[progressView release];
[localFilename release];
[receivedData release];
[DownloadRequest release];
[DownloadConnection release];
[lblDownloadBytes release];
[lblDownloadPercent release];
[super dealloc];
}
@end
调用方式
self.userInteractionEnabled = NO;
[self addSubview:mask];
UIDownloadBar *downloadBar = [[UIDownloadBar alloc]initWithURL:[NSURL URLWithString:selectedCity.dbpath]
progressBarFrame:CGRectMake（50, 130, 220, 80）
timeout:5
delegate:self];
[self addSubview:downloadBar];
注意要实现delegate的三个方法
- （void）downloadBar:（UIDownloadBar *）downloadBar didFinishWithData:（NSData *）fileData suggestedFilename:（NSString *）filename{
[self showDownloadCompleteView:downloadBar msg:@"离线公交数据下载完成"];
}
- （void）downloadBar:（UIDownloadBar *）downloadBar didFailWithError:（NSError *）error{
[self showDownloadCompleteView:downloadBar msg:@"下载失败"];
}
- （void）downloadBarUpdated:（UIDownloadBar *）downloadBar{
}
可以用一个label提示下载成功或者失败
-（void）showDownloadCompleteView:（UIDownloadBar*）downloadBar msg:（NSString*）message{
[mask performSelector:@selector（removeFromSuperview）
withObject:nil
afterDelay:1.5];
[UIView animateWithDuration:2
animations:^{
downloadBar.alpha = 0;
}];
[downloadBar performSelector:@selector（removeFromSuperview）
withObject:nil
afterDelay:2];
self.userInteractionEnabled = YES;
UILabel *successAlert = [[UILabel alloc]initWithFrame:
CGRectMake（60, 250, 200, 40）];
successAlert.textColor = [UIColor whiteColor];
successAlert.backgroundColor = [UIColor lightGrayColor];
successAlert.layer.borderColor = [UIColor whiteColor].CGColor;
successAlert.layer.cornerRadius = 5;
successAlert.layer.borderWidth = 2.0;
successAlert.textAlignment = UITextAlignmentCenter;
successAlert.text = message;
[self addSubview:successAlert];
//慢慢变透明，然后消失
[UIView animateWithDuration:2
animations:^{
successAlert.alpha = 0;
}];
[successAlert performSelector:@selector（removeFromSuperview）
withObject:nil
afterDelay:2];
}
本文出自 “iphone开发” 博客，请务必保留此出处http://yuyi123.blog.51cto.com/1987900/504457
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