iOS UIWebview 快取檔案。，iosuiwebview

iOS UIWebview 快取檔案。，iosuiwebview

最初我以為:

testCache = [[NSURLCache alloc]initWithMemoryCapacity:1024*1024*12 diskCapacity:1024*1024*120 diskPath:@"Assitant.db"];    [NSURLCache setSharedURLCache:testCache];

就能讓webview自動的控制緩衝，沒想到圖片還是每次都在重新載入。實在就想不通了，120M還存不下？不知道是不是我用法沒對。

後來經過一番查閱之後，發現似乎要自己實現緩衝的讀寫！於是寫了一個，花了三天時間，開始總是發現似乎寫入成功了，但再進入有沒有了。經過3天才發現是被我自己刪除了，裡面的刪除函數，每次程式啟動都會進行刪除，無語了。

網上的資料確實不少，五花八門，不是過時了，就是不靠譜（此文寫與2014－11-08 22:13，iOS7）。

上代碼，使用方法在最下面。

////  MyUrlCache.h//  com.lcst.miniBrowser////  Created by lein on 14-11-5.//  Copyright (c) 2014年 lein. All rights reserved.//#import <Foundation/Foundation.h>@interface MyUrlCache : NSURLCache- (NSCachedURLResponse *)cachedResponseForRequest:(NSURLRequest *)request;- (void) storeCachedResponse:(NSCachedURLResponse *)cachedResponse forRequest:(NSURLRequest *)request;- (void) initilize;- (void) doRemoveAllCachedResponses;@end

////  MyUrlCache.m//  com.lcst.miniBrowser////  Created by lein on 14-11-5.//  Copyright (c) 2014年 lein. All rights reserved.//#import "MyUrlCache.h"#import "Utils.h"@implementation MyUrlCache#define WILL_BE_CACHED_EXTS ".jpg.png.gif.bmp.ico"#define DEBUGP//#define WILL_BE_CACHED_EXTS ".html"NSString * spath;NSFileManager *fileManager;NSString* dirName=@"httpCache";NSInteger dirType = 0;-(void) initilize{    fileManager = [NSFileManager defaultManager];    NSArray *paths = NSSearchPathForDirectoriesInDomains((dirType==0?NSDocumentDirectory:(dirType==1?NSLibraryDirectory:NSCachesDirectory)), NSUserDomainMask, YES);        spath =[paths objectAtIndex:0];    [fileManager changeCurrentDirectoryPath:spath];    spath = [spath stringByAppendingPathComponent:dirName];    [fileManager changeCurrentDirectoryPath:spath];}- (void)removeAllCachedResponses{    //這裡不能執行doRemoveAllCachedResponses，否則每次就會刪除你寫入的}- (void) doRemoveAllCachedResponses{    if (spath!=nil) {        [fileManager removeItemAtPath:spath error:nil];    }}- (NSString *) getMineType:(NSURLRequest *)request{    NSString *ext = [[request URL] absoluteString].pathExtension;    if(ext!=nil){        NSString* str;        if([ext compare:@"htm"]||[ext compare:@"html"])            str = @"text/html";        else            str = [NSString stringWithFormat:@"image/%@", ext];        return str;    }    return @"";}- (NSCachedURLResponse *)cachedResponseForRequest:(NSURLRequest *)request {    NSString* filename = [self getCachedFileName:request];    if(spath!=nil && filename.length>0){        filename = [spath stringByAppendingPathComponent:filename];        if([fileManager fileExistsAtPath:filename]){#ifdef DEBUGP            NSLog(@"\n注意：：：：Cache used: %@", [[request URL] absoluteString]);#endif            NSData* data = [NSData dataWithContentsOfFile:filename];            NSURLResponse *response = [[NSURLResponse alloc] initWithURL:request.URL MIMEType:[self getMineType:request] expectedContentLength:data.length textEncodingName:nil];            NSCachedURLResponse* cachedResponse = [[NSCachedURLResponse alloc] initWithResponse:response data:data];                        return cachedResponse;        }    }    return nil;    }- (void)storeCachedResponse:(NSCachedURLResponse *)cachedResponse forRequest:(NSURLRequest *)request {    NSString* filename = [self getCachedFileName:request];    if(spath!=nil && filename.length>0){        if(![fileManager fileExistsAtPath:filename]){            filename = [Utils writeFileToDirWithDirType:dirName dirType:dirType fileName:filename DATA:cachedResponse.data];#ifdef DEBUGP            NSLog(@"\n注意：：：：寫入快取檔案=%@",filename );#endif        }    }#ifdef DEBUGP    else        NSLog(@"\n注意：：：：不緩衝: %@", [[request URL] absoluteString]);#endif}- (NSString*) getCachedFileName:(NSURLRequest *) request{    NSString *ext = [[request URL] absoluteString].pathExtension;    if(ext!=nil){        if([@WILL_BE_CACHED_EXTS rangeOfString:ext.lowercaseString].length>0){            return [NSString stringWithFormat:@"%@.%@", [Utils md5:[[request URL] absoluteString]], ext];        }    }    return @"";}@end

////  Utils.h//  com.lcst.miniBrowser////  Created by lein on 14-8-4.//  Copyright (c) 2014年 lein. All rights reserved.//#import <Foundation/Foundation.h>#import <CommonCrypto/CommonDigest.h>@interface Utils : NSObject+(void) writeFile:(NSString *) filePath data:(NSString *) _data;+(NSString *) readFile:(NSString *) filePath;+(NSString *) md5:(NSString *)str;+(NSString *) replaceStringBetween:(NSString *) startStr EndString:(NSString *) endString Str:(NSString *) str;+(NSInteger)getTs;+(NSData *)uncompressZippedData:(NSData *)compressedData;+(NSString*) writeFileToDirWithDirType:(NSString*) dirname dirType:(NSInteger) type fileName:(NSString*) filename DATA:(NSData *) data;+(NSData*) readFileFromDirWithDirType:(NSString*) dirname dirType:(NSInteger) type fileName:(NSString*) filename;@end

////  Utils.m//  com.lcst.miniBrowser////  Created by lein on 14-8-4.//  Copyright (c) 2014年 lein. All rights reserved.//#import "Utils.h"#import <zlib.h>@implementation Utils+(void) writeFile:(NSString *) filePath data:(NSString *) _data{    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);    NSString* fileName = [[paths objectAtIndex:0] stringByAppendingPathComponent:filePath];           // 用這個方法來判斷當前的檔案是否存在，如果不存在，就建立一個檔案    NSFileManager *fileManager = [NSFileManager defaultManager];    if ( ![fileManager fileExistsAtPath:fileName]) {        NSLog(@"File %@ not exists!", fileName);        [fileManager createFileAtPath:fileName contents:nil attributes:nil];    }else NSLog(@"File %@ exists!", fileName);     NSLog(@"File %@ will write!", fileName);    [_data writeToFile:fileName atomically:YES encoding:NSUTF8StringEncoding error:nil];}+(NSString *) replaceStringBetween:(NSString *) startStr EndString:(NSString *) endString Str:(NSString *) str{    NSRange range1 = [str rangeOfString:startStr];    int len = str.length - range1.location - range1.length;        NSRange range2 = [str rangeOfString:endString options:NSCaseInsensitiveSearch range:NSMakeRange(range1.location+range1.length, len)];        int start =range1.length+range1.location;    len = range2.location-(range1.length+range1.location);    NSString* toReplace = [str substringWithRange:NSMakeRange(start, len)];    return [str stringByReplacingOccurrencesOfString:toReplace withString:@""];}+(NSString *) readFile:(NSString *) filePath{    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);    NSString* fileName = [[paths objectAtIndex:0]stringByAppendingPathComponent:filePath];    NSLog(@"File %@ will be read!", fileName);    NSString* myString = [NSString stringWithContentsOfFile:fileName usedEncoding:NULL error:NULL];    return myString;}//md5 32位 加密 （小寫）+ (NSString *)md5:(NSString *)srcString {    const char *cStr = [srcString UTF8String ];        unsigned char digest[ CC_MD5_DIGEST_LENGTH ];        CC_MD5 ( cStr, (CC_LONG) strlen (cStr), digest );        NSMutableString *result = [ NSMutableString stringWithCapacity : CC_MD5_DIGEST_LENGTH * 2 ];        for ( int i = 0 ; i < CC_MD5_DIGEST_LENGTH ; i++)                [result appendFormat : @"%02x" , digest[i]];        return result;}+ (NSInteger)getTs{    NSDate *date = [NSDate date];    NSTimeInterval timestamp = [date timeIntervalSince1970];            return (NSInteger) timestamp;}+(NSData *)uncompressZippedData:(NSData *)compressedData{    if ([compressedData length] == 0) return compressedData;    unsigned full_length = [compressedData length];    unsigned half_length = [compressedData length] / 2;    NSMutableData *decompressed = [NSMutableData dataWithLength: full_length + half_length];    BOOL done = NO;    int status;    z_stream strm;    strm.next_in = (Bytef *)[compressedData bytes];    strm.avail_in = [compressedData length];    strm.total_out = 0;    strm.zalloc = Z_NULL;    strm.zfree = Z_NULL;    if (inflateInit2(&strm, (15+32)) != Z_OK) return nil;    while (!done) {        // Make sure we have enough room and reset the lengths.        if (strm.total_out >= [decompressed length]) {            [decompressed increaseLengthBy: half_length];        }        strm.next_out = [decompressed mutableBytes] + strm.total_out;        strm.avail_out = [decompressed length] - strm.total_out;        // Inflate another chunk.        status = inflate (&strm, Z_SYNC_FLUSH);        if (status == Z_STREAM_END) {            done = YES;        } else if (status != Z_OK) {            break;        }    }    if (inflateEnd (&strm) != Z_OK) return nil;    // Set real length.    if (done) {        [decompressed setLength: strm.total_out];        return [NSData dataWithData: decompressed];    } else {        return nil;    }}+(NSString*) writeFileToDirWithDirType:(NSString*) dirname dirType:(NSInteger) type fileName:(NSString*) filename DATA:(NSData *) data{    NSFileManager* fileManager = [NSFileManager defaultManager];    NSArray *paths = NSSearchPathForDirectoriesInDomains((type==0?NSDocumentDirectory:(type==1?NSLibraryDirectory:NSCachesDirectory)), NSUserDomainMask, YES);    NSString* spath =[paths objectAtIndex:0];    [fileManager changeCurrentDirectoryPath:spath];    if(dirname.length>0){        [fileManager createDirectoryAtPath:dirname withIntermediateDirectories:YES attributes:nil error:nil];        spath = [NSString stringWithFormat:@"%@/%@/%@", spath, dirname, filename];    }else        spath = [NSString stringWithFormat:@"%@/%@", spath, filename];        [fileManager createFileAtPath:spath contents:data attributes:nil];    return spath;}+(NSData*) readFileFromDirWithDirType:(NSString*) dirname dirType:(NSInteger) type fileName:(NSString*) filename{    NSArray *paths = NSSearchPathForDirectoriesInDomains((type==0?NSDocumentDirectory:(type==1?NSLibraryDirectory:NSCachesDirectory)), NSUserDomainMask, YES);    NSString* spath =[paths objectAtIndex:0];        if(dirname.length>0)        spath = [NSString stringWithFormat:@"%@/%@/%@", spath, dirname, filename];    else        spath = [NSString stringWithFormat:@"%@/%@", spath, filename];        return [[NSData alloc] initWithContentsOfFile:spath];}@end

使用，在viewDidAppear：

testCache = [[MyUrlCache alloc]initWithMemoryCapacity:1024*1024*12 diskCapacity:1024*1024*120 diskPath:@"jiayuanAssitant.db"];    [testCache initilize];        [NSURLCache setSharedURLCache:testCache];

順便提一下，iOS模擬器的硬碟位置在：/Users/mac使用者名稱/Library/Application Support/iPhone Simulator；因為一直在真機上弄，連檔案夾建立起沒有都不知道，以至於糾結了三天，在模擬器上一看，才找到原因。