IOS UI multithreaded Nsthread download and display pictures to Uiimageview

@property (weak,nonatomic) Iboutletuilabel *downlabelinfo;

@property (weak,nonatomic) Iboutletuiimageview *imageview;

@end

@implementationViewController

-(void) viewdidload

{

[Super Viewdidload];

NSString *url [email protected] "http://d.hiphotos.baidu.com/image/w%3D1366%3Bcrop%3D0%2C0%2C1366%2C768/sign= 6cbcab9dabec8a13141a53e3c135aaec/aa64034f78f0f7369453c3730855b319ebc41316.jpg ";

@autoreleasepool {

Nsthread *thread = [[Nsthreadalloc]initwithtarget:selfselector: @selector (downloadimage:) Object:url];

[Thread start];

}

}

-(void) didreceivememorywarning

{

[Super didreceivememorywarning];

}

-(void) Downloadimage: (NSString *) URL {

To put the displayed content in front of the synchronization method

Self->_downlabelinfo.text [email protected] "Downloading pictures ...";

The synchronization method will card the thread until the completion position

NSData *imagedata = [Nsdatadatawithcontentsofurl:[nsurlurlwithstring:url]];

UIImage *image =[uiimageimagewithdata:imagedata];

if (Image==nil)

{

}

Else

{

Self->_downlabelinfo.text = @ "Downloading pictures ..."; so it's useless to write this statement.

[Self Performselectoronmainthread: @selector (updateimageview:) Withobject: (image) Waituntildone:yes];

}

}

-(void) Updateimageview: (UIImage *) image

{

Self->_imageview.image = image;

Self->_imageview.frame=cgrectmake (self.view.frame.size.width/2-100,self.view.frame.size.height/2-100,200, 200);

Self->_downlabelinfo.textcolor = [Uicolorredcolor];

Self->_downlabelinfo.text [email protected] "Picture Download complete";

}

@end

The second way is to use nsurlconnection sendsynchronousrequest sync to get the picture content and display

Modify the Downloadimage method as follows

-(void) Downloadimage: (NSString *) URL

{

Self->_downlabelinfo.text [email protected] "Downloading pictures ...";

Nsurlrequest *request = [Nsurlrequestrequestwithurl:[nsurlurlwithstring:url]];

Nserror *error;

This will cause blocking

NSData *data = [nsurlconnectionsendsynchronousrequest:requestreturningresponse:nilerror:&error];

if (data ==nil)

{

NSLog (@ "nil");

}

Else

{

UIImage *image =[uiimageimagewithdata:data];

Self->_imageview.image = image;

Self->_downlabelinfo.textcolor = [Uicolorredcolor];

Self->_downlabelinfo.text [email protected] "Picture Download complete";

}

}