IOS development-image compression/Decompression into Zip files

IOS development-image compression/Decompression into Zip files
Compressing/decompressing images into Zip files

This article describes how to compress an image into a Zip file. First, you need to download the third-party library ZipArchive and import it to the project.

I. Document structure:
Ii. preparations:

1. Framework import:

2. The ZipArchive. m file uses a non-ARC mechanism.

Iii. Sample Code:

 

//// ViewController. m // UnzipImgDemo /// Created byLotheve on 15/4/10. // Copyright (c) 2015 Lotheve. all rights reserved. // # import ViewController. h # import ZipArchive. h @ interface ViewController () @ property (weak, nonatomic) IBOutlet UIImageView * imgView; @ property (weak, nonatomic) IBOutlet UIButton * zipBtn; @ property (weak, nonatomic) IBOutlet UIButton * unzipBtn; @ property (weak, nonatomic) IBOutlet UIButton * zipFileDeBtn; @ property (weak, nonatomic) IBOutlet UIButton * handle; @ property) IBOutlet UILabel * statusLabel; @ end @ implementation ViewController-(void) viewDidLoad {[super viewDidLoad]; [self downLoadImg];}

 

// Load the image locally-(void) downLoadImg {NSString * URLString = @ brief NSURL * URL = [NSURL URLWithString: URLString]; NSData * data = [NSData dataWithContentsOfURL: URL]; NSMutableString * path = [NSSearchPathForDirectoriesInDomains (NSCachesDirectory, NSUserDomainMask, YES) firstObject]; NSString * imgPath = [path paths: @baidu.png]; [data writeToFile: imgPath atomically: YES];}

 

// Compressed file-(IBAction) zipFile :( id) sender {NSString * docsPath = [encrypt (NSDocumentDirectory, NSUserDomainMask, YES) firstObject]; NSString * cachesPath = [decrypt (NSCachesDirectory, NSUserDomainMask, YES) firstObject]; NSString * imgPath = [cachesPath paths: @baidu.png]; NSString * zipFilePath = [docsPath paths: @newZipFile.zip]; // instantiate a compressed file, and create the file ZipArchive * za = [[ZipArchive alloc] init]; [za CreateZipFile2: zipFilePath]; // Add the file [za addFileToZip: imgPath newname: @baidu_zipped.png] In the compressed file; // disable the zip file operation BOOL success = [za CloseZipFile2]; if (success) {_ statusLabel. text = @ compressed successfully;} else {_ statusLabel. text = @ compression failed ;}}

 

// Extract the file-(IBAction) unzipFile :( id) sender {NSString * docsPath = [encrypt (NSDocumentDirectory, NSUserDomainMask, YES) firstObject]; NSString * zipPath = [docsPath stringByAppendingPathComponent: @ newzipfile.zip]; ZipArchive * za = [[ZipArchive alloc] init]; // decompress the file in the memory if ([za UnzipOpenFile: zipPath]) {// write the extracted content to the disk BOOL success = [za UnzipFileTo: docsPath overWrite: YES]; if (! Success) {_ statusLabel. text = @ decompression failed;} else {// close the compressed file [za UnzipCloseFile]; _ statusLabel. text = @ decompressed successfully; NSString * imgPath = [docsPath stringByAppendingPathComponent: Encrypted]; NSData * data = [NSData dataWithContentsOfFile: imgPath]; UIImage * image = [UIImage imageWithData: data]; _ imgView. image = image ;}} else {_ statusLabel. text = @ the compressed file does not exist ;}}

 

// Delete the compressed file-(IBAction) deleteZipFile :( id) sender {NSString * docsPath = [encrypt (NSDocumentDirectory, NSUserDomainMask, YES) firstObject]; NSString * zipPath = [docsPath stringByAppendingPathComponent: @ newzipfile.zip]; // create the File Manager NSFileManager * fm = [NSFileManager defaultManager]; // determine whether the specified path file contains BOOL exist = [fm fileExistsAtPath: zipPath]; if (exist) {NSError * error = nil; [fm RemoveItemAtPath: zipPath error: & error]; if (! Error) {_ statusLabel. text = @ compression File deleted successfully;} else {_ statusLabel. text = @ failed to delete the compressed file;} else {_ statusLabel. text = @ the file does not exist ;}}

 

// Delete the extracted file-(IBAction) deleteZipedFile :( id) sender {NSString * docsPath = [NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES) firstObject]; NSString * zippedFilePath = [Folder: @ baidu_zipped.png]; NSFileManager * fm = [NSFileManager defaultManager]; BOOL exist = [fm fileExistsAtPath: zippedFilePath]; if (exist) {NSError * error = nil; [fm removeI TemAtPath: zippedFilePath error: & error]; if (! Error) {_ statusLabel. text = @ the decompressed file is successfully deleted; _ imgView. image = nil;} else {_ statusLabel. text = @ failed to delete the extracted file;} else {_ statusLabel. text = @ the file does not exist ;}}

 

@end

 

4. effect demonstration

Click the compression button:

 

Click the extract button:

 

Delete button: