IOS--Get the size of local pictures and network pictures

// gets the size        of the picture Cgsize size = [UIImage imagenamed:@ "regstep2_sex"].size;

to get the size of a network picture:

//get picture size based on image URL+ (Cgsize) Getimagesizewithurl: (ID) imageurl{Nsurl* URL =Nil; if([ImageURL Iskindofclass:[nsurlclass]]) {URL=ImageURL; }    if([ImageURL iskindofclass:[nsstringclass]]) {URL=[Nsurl Urlwithstring:imageurl]; }    if(URL = =Nil)returnCgsizezero;//URL returned incorrectly Cgsizezeronsmutableurlrequest*request =[[Nsmutableurlrequest alloc] initwithurl:url]; NSString* Pathextendsion =[Url.pathextension lowercasestring]; Cgsize size=Cgsizezero; if([Pathextendsion isequaltostring:@"PNG"]) {size=[self getpngimagesizewithrequest:request]; }    Else if([Pathextendsion isequal:@"gif"]) {size=[self getgifimagesizewithrequest:request]; }    Else{size=[self getjpgimagesizewithrequest:request]; }    if(Cgsizeequaltosize (Cgsizezero, size))//sending an asynchronous request to request the original image if the file header information fails to get{NSData* data =[nsurlconnection sendsynchronousrequest:[nsurlrequest Requestwithurl:url] Returningresponse:nil Error:nil]; UIImage* Image =[UIImage Imagewithdata:data]; if(image) {size=image.size; }    }    returnsize;}//get the size of a PNG picture+ (Cgsize) Getpngimagesizewithrequest: (nsmutableurlrequest*) request{[request SetValue:@"bytes=16-23"Forhttpheaderfield:@"Range"]; NSData* data =[nsurlconnection sendsynchronousrequest:request returningresponse:nil Error:nil]; if(Data.length = =8)    {        intW1 =0, W2 =0, W3 =0, W4 =0; [Data getBytes:&AMP;W1 Range:nsmakerange (0,1)]; [Data getBytes:&AMP;W2 Range:nsmakerange (1,1)]; [Data getBytes:&AMP;W3 Range:nsmakerange (2,1)]; [Data getBytes:&w4 Range:nsmakerange (3,1)]; intW = (W1 << -) + (W2 << -) + (W3 <<8) +W4; intH1 =0, H2 =0, h3 =0, H4 =0; [Data getBytes:&h1 Range:nsmakerange (4,1)]; [Data getBytes:&h2 Range:nsmakerange (5,1)]; [Data getBytes:&h3 Range:nsmakerange (6,1)]; [Data getBytes:&h4 Range:nsmakerange (7,1)]; inth = (H1 << -) + (H2 << -) + (H3 <<8) +h4; returnCgsizemake (W, h); }    returnCgsizezero;}//get the size of a GIF picture+ (Cgsize) Getgifimagesizewithrequest: (nsmutableurlrequest*) request{[request SetValue:@"bytes=6-9"Forhttpheaderfield:@"Range"]; NSData* data =[nsurlconnection sendsynchronousrequest:request returningresponse:nil Error:nil]; if(Data.length = =4)    {         ShortW1 =0, W2 =0; [Data getBytes:&AMP;W1 Range:nsmakerange (0,1)]; [Data getBytes:&AMP;W2 Range:nsmakerange (1,1)];  ShortW = W1 + (W2 <<8);  ShortH1 =0, H2 =0; [Data getBytes:&h1 Range:nsmakerange (2,1)]; [Data getBytes:&h2 Range:nsmakerange (3,1)];  ShortH = h1 + (H2 <<8); returnCgsizemake (W, h); }    returnCgsizezero;}//get the size of a JPG picture+ (Cgsize) Getjpgimagesizewithrequest: (nsmutableurlrequest*) request{[request SetValue:@"bytes=0-209"Forhttpheaderfield:@"Range"]; NSData* data =[nsurlconnection sendsynchronousrequest:request returningresponse:nil Error:nil]; if([Data length] <=0x58) {        returnCgsizezero; }         if([Data length] < About) {//there must be only one DQT field         ShortW1 =0, W2 =0; [Data getBytes:&AMP;W1 Range:nsmakerange (0x60,0x1)]; [Data getBytes:&AMP;W2 Range:nsmakerange (0x61,0x1)];  ShortW = (W1 <<8) +W2;  ShortH1 =0, H2 =0; [Data getBytes:&h1 Range:nsmakerange (0x5e,0x1)]; [Data getBytes:&h2 Range:nsmakerange (0x5f,0x1)];  Shorth = (H1 <<8) +H2; returnCgsizemake (W, h); } Else {         ShortWord =0x0; [Data getBytes:&word Range:nsmakerange (0x15,0x1)]; if(Word = =0xdb) {[Data getBytes:&word Range:nsmakerange (0x5a,0x1)]; if(Word = =0xdb) {//two x DQT fields                 ShortW1 =0, W2 =0; [Data getBytes:&AMP;W1 Range:nsmakerange (0xa5,0x1)]; [Data getBytes:&AMP;W2 Range:nsmakerange (0xa6,0x1)];  ShortW = (W1 <<8) +W2;  ShortH1 =0, H2 =0; [Data getBytes:&h1 Range:nsmakerange (0xa3,0x1)]; [Data getBytes:&h2 Range:nsmakerange (0xa4,0x1)];  Shorth = (H1 <<8) +H2; returnCgsizemake (W, h); } Else{//a DQT field                 ShortW1 =0, W2 =0; [Data getBytes:&AMP;W1 Range:nsmakerange (0x60,0x1)]; [Data getBytes:&AMP;W2 Range:nsmakerange (0x61,0x1)];  ShortW = (W1 <<8) +W2;  ShortH1 =0, H2 =0; [Data getBytes:&h1 Range:nsmakerange (0x5e,0x1)]; [Data getBytes:&h2 Range:nsmakerange (0x5f,0x1)];  Shorth = (H1 <<8) +H2; returnCgsizemake (W, h); }        } Else {            returnCgsizezero; }    }}

IOS--Get the size of local pictures and network pictures