Nsurlconnection Large File Download

#import "ViewController.h"

@interface Viewcontroller () <nsurlconnectiondatadelegate>

@property (weak, nonatomic) iboutlet uiprogressview *progressview;

@property (nonatomic, assign) nsinteger totalsize;

@property (nonatomic, assign) nsinteger currentsize;

/** Sandbox Path * /

@property (nonatomic, strong) nsstring *fullpath;

/** Connection Object * /

@property (nonatomic, strong) nsurlconnection *connect;

/** Output Stream * /

@property (nonatomic, strong) nsoutputstream *stream;

@end

@implementation Viewcontroller

-(ibaction) Startbtnclick: (ID) Sender {

[self download];

}

-(ibaction) Cancelbtnclick: (ID) Sender {

[self. Connect cancel];

}

-(ibaction) Goonbtnclick: (ID) Sender {

[self download];

}

Memory Spike

-(void) Download

{

//1.url

nsurl *url = [nsurl urlwithstring:@ "http://www.33lc.com/article/UploadPic/2012-10/ 2012102514201759594.jpg "];

//2. Create Request Object

nsmutableurlrequest *request = [nsmutableurlrequest requestwithurl: url];

// Set the request header information to tell the server value to request part of the data range

/*

bytes=0-100

bytes=-100

bytes=0- all data after the request

*/

nsstring *range = [nsstring stringwithformat:@ "bytes=%zd-",self. CurrentSize];

[Request SetValue: Range Forhttpheaderfield:@ "range"];

NSLog(@ "+++++++%@", Range);

//3. Send Request

nsurlconnection *connect = [[nsurlconnection alloc]initwithrequest: Request delegate:self];

self. Connect = connect;

}

#pragma Mark----------------------

#pragma Mark Nsurlconnectiondatadelegate

-(void) connection: (nsurlconnection *) connection didreceiveresponse: (nsurlresponse * ) Response

{

NSLog(@ "Didreceiveresponse");

//1. Gets the total size of the file (the total size of the file data for this request!! = file )

//Self.totalsize = Response.expectedcontentlength + self.currentsize;

if (self. CurrentSize >0) {

return;

}

self. TotalSize = response. Expectedcontentlength;

//2. write the data into the sandbox

self. FullPath = [[nssearchpathfordirectoriesindomains(nscachesdirectory, nsuserdomainmask , YES) lastobject]stringbyappendingpathcomponent:@ "123.jpg"];

NSLog(@ "%@",self. FullPath);

//3. Create an output stream

Nsoutputstream

Nsinputstream

/*

first parameter : the path to a file

second parameter : YES append

feature : if the output stream points to an address that does not have a file, an empty file is created automatically

*/

nsoutputstream *stream = [[nsoutputstream alloc]inittofileatpath:Self . fullPath append:YES];

// open output stream

[Stream open];

self. Stream = stream;

}

-(void) connection: (nsurlconnection *) connection didreceivedata: (nsdata *) Data

{

// Write Data

[self. Stream write:d ata. Bytes maxLength:d ata. Length];

//3. Get Progress

self. CurrentSize + = data. Length;

// Progress = Total size of downloaded/file

NSLog(@ "%f",1.0 * self. CurrentSize/self. TotalSize);

self. Progressview. Progress = 1.0 * self. CurrentSize/self. TotalSize;

//nslog (@ "%@", Self.fullpath);

}

-(void) connection: (nsurlconnection *) connection didfailwitherror: (nserror *) Error

{

}

-(void) connectiondidfinishloading: (nsurlconnection *) connection

{

// close stream

[self. Stream close];

self. Stream = nil;

NSLog(@ "connectiondidfinishloading");

NSLog(@ "%@",self. FullPath);

}

@end

Nsurlconnection Large File Download