需求分析
项目中要用WKWebView显示PDF链接，发现用系统自带的缓存策略在网络差的时候，加载不出来。于是，为了更好的用户体验，还是自己做一个本地存储的逻辑。这样，无论网络好坏，只要本地下载了PDF文件就可以快速从本地加载出来。同时，还有另外一个问题，当跳到下一个页面再回来的时候，WebView变白了，又要重新加载数据，这个时候如果本地存储了PDF文件的话，页面显示出来就快很多。
WKWebView自带缓存策略
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-(WKWebView *)originWebView{
if (!_originWebView) {
WKWebViewConfiguration *config = [[WKWebViewConfiguration alloc] init];
//这个类主要用来做native与JavaScript的交互管理
WKUserContentController * wkUController = [[WKUserContentController alloc] init];
config.userContentController = wkUController;
//禁止缩放
NSString *js = @" $('meta[name=description]').remove(); $('head').append( '' );";
WKUserScript *wkUScript = [[WKUserScript alloc] initWithSource:js injectionTime:WKUserScriptInjectionTimeAtDocumentEnd forMainFrameOnly:NO];
[config.userContentController addUserScript:wkUScript];
_originWebView = [[WKWebView alloc] initWithFrame:CGRectMake(0,0,kFullScreenWidth,kFullScreenHeight-kStatusBarAndNavigationBarHeight) configuration:config];
_originWebView.backgroundColor = [UIColor generateDynamicColor:UIColorFromHex(COLOR_FFFFFF) darkColor:UIColorFromHex(COLOR_000000)];
_originWebView.navigationDelegate = self;
_originWebView.UIDelegate = self;
_originWebView.navigationDelegate = self;
_originWebView.scrollView.showsVerticalScrollIndicator = NO;
_originWebView.scrollView.showsHorizontalScrollIndicator = NO;
}
return _originWebView;
}
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[self loadRequestWithFileModel:self.fileModel.originQuestionPdfUrl wkWebView:self.originWebView];
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-(void)loadRequestWithFileModel:(NSString*)fileUrl wkWebView:(WKWebView *)webView{
NSString *pdfUrl =[NSString stringWithFormat:@"%@%@",kHOST_ADDRESS,fileUrl];
NSString *encodedString = (NSString *)CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes (kCFAllocatorDefault, (CFStringRef)pdfUrl,(CFStringRef) @"!NULL,'()*+,-./:;=?@_~%#[]", NULL, kCFStringEncodingUTF8));
NSURL *filePath = [NSURL URLWithString:encodedString]; // NSURLRequestReturnCacheDataDontLoad NSURLRequestReloadIgnoringLocalCacheData
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:filePath cachePolicy:NSURLRequestReturnCacheDataElseLoad timeoutInterval:10];
[webView loadRequest:request];
}
WKWebView自定义本地存储逻辑
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-(void)getDataWithPdfUrl:(NSString *)fileUrl isOrigin:(BOOL)isOrigin{
//判断文件是否存在
NSString *fileName = [[SSPDownloadPdfFileManager shareInstance] getFileNameWithFileUrl:fileUrl withPrintId:self.fileModel.printingId withSubject:self.fileModel.subject];
if ([[SSPDownloadPdfFileManager shareInstance] isSavedFileToLocalWithFileName:fileName filePath:LOCAL_ERROROBOOK_PATH]) {
NSURL *pdfUrl = [[SSPDownloadPdfFileManager shareInstance] getLocalFilePathWithfileName:fileName withLocalPath:LOCAL_ERROROBOOK_PATH];
[self loadRequestWithFileUrl:pdfUrl isOrigin:isOrigin];
}else{
[self savePdfFileWithFileUrl:fileUrl isOrigin:isOrigin];//直接下载数据
}
}
-(void)savePdfFileWithFileUrl:(NSString *)fileUrl isOrigin:(BOOL)isOrigin{
NSString *fileName = [[SSPDownloadPdfFileManager shareInstance] getFileNameWithFileUrl:fileUrl withPrintId:self.fileModel.printingId withSubject:self.fileModel.subject];
//文件路径存在 直接下载
NSString *pdfUrl =[NSString stringWithFormat:@"%@%@",kHOST_ADDRESS,fileUrl];
NSString *encodedString = (NSString *)CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes (kCFAllocatorDefault, (CFStringRef)pdfUrl,(CFStringRef) @"!NULL,'()*+,-./:;=?@_~%#[]", NULL, kCFStringEncodingUTF8));
[[SSPDownloadPdfFileManager shareInstance] downloadFileWithFileUrl:encodedString fileName:fileName filePath:LOCAL_ERROROBOOK_PATH downLoadSuccess:^(NSURLResponse * _Nonnull response, NSURL * _Nullable filePath) {
[self loadRequestWithFileUrl:filePath isOrigin:isOrigin];
} downLoadFail:^(NSURLResponse * _Nonnull response, NSError * _Nullable error) {
} progress:^(NSProgress * _Nonnull downloadProgress) {
}];
}
-(void)loadRequestWithFileUrl:(NSURL *)fileUrl isOrigin:(BOOL)isOrigin{
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:fileUrl];
if (isOrigin) {
[self.originWebView loadRequest:request];
}else {
[self.analysisWebView loadRequest:request];
}
}
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#define LOCAL_ERROROBOOK_PATH @"Documents/SharingSchool/ErrorBook"
-(NSString *)getFileNameWithFileUrl:(NSString *)fileUrl withPrintId:(NSString *)printId withSubject:(NSString *)subject{
NSString *newFileUrl = [fileUrl stringByReplacingOccurrencesOfString:@"/" withString:@"_"];
NSString *fileName = [NSString stringWithFormat:@"%@_%@_%@",subject,printId,newFileUrl];
return fileName;
}
-(BOOL)isSavedFileToLocalWithFileName:(NSString *)fileName filePath:(NSString *)filePath{
NSString *documentsDirectory = [NSHomeDirectory() stringByAppendingPathComponent:filePath];
NSString *recordPath = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"/%@",fileName]];
if (![self creatFile:documentsDirectory]) {
return NO;
}
NSFileManager *filemanager = [NSFileManager defaultManager];
if ([filemanager fileExistsAtPath:recordPath]) {
return YES;
}
return NO;
}
-(BOOL)creatFile:(NSString*)filePath{
if (filePath.length==0) {
return NO;
}
NSFileManager *fileManager = [NSFileManager defaultManager];
if ([fileManager fileExistsAtPath:filePath]) {
return YES;
}
NSError *error;
BOOL isSuccess = [fileManager createDirectoryAtPath:filePath withIntermediateDirectories:YES attributes:nil error:&error]; // 在Documetnts目录中创建名为XXX的目录
if (error) {
NSLog(@"creat File Failed:%@",[error localizedDescription]);
}
if (!isSuccess) {
return isSuccess;
}
isSuccess = [fileManager createFileAtPath:filePath contents:nil attributes:nil]; //在XXX目录里，创建文件XXX
return isSuccess;
}
-(NSURL *)getLocalFilePathWithfileName:(NSString *)fileName withLocalPath:(NSString *)localPath{
NSString *documentsDirectory = [NSHomeDirectory() stringByAppendingPathComponent:localPath];
NSFileManager *filemanager = [NSFileManager defaultManager];
NSArray *fileList = [filemanager subpathsOfDirectoryAtPath:documentsDirectory error:nil];
if ([fileList containsObject:fileName]) {
NSString *fileUrltemp = [NSString stringWithFormat:@"%@/%@", documentsDirectory,fileName];
NSURL *url = [NSURL fileURLWithPath:fileUrltemp];
return url;
}
return nil;
}
+ (BOOL)checkUrlWithString:(NSString *)url {
NSString *regex =@"[a-zA-z]+://[^\\s]*";
NSPredicate *urlTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",regex];
return [urlTest evaluateWithObject:url];
}
- (void)downloadFileWithFileUrl:(NSString *)requestURL
fileName:(NSString *)fileName
filePath:(NSString *)filePath
downLoadSuccess:(DownLoadFileSuccessBlock)successBlcok
downLoadFail:(DownLoadFileFailureBlock)failureBlock
progress:(DownLoadFileProgressBlcok)progressBlock {
AFURLSessionManager *manager = [[AFURLSessionManager alloc] initWithSessionConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration]];
/* 下载地址 qu*/
NSURL *url;
if ([SSUtility checkUrlWithString:requestURL]) {
url = [NSURL URLWithString:requestURL];
}else {
url = [NSURL URLWithString:[NSString stringWithFormat:@"%@%@",kHOST_ADDRESS,requestURL]];
}
NSURLRequest *request = [NSURLRequest requestWithURL:url];
/* 下载路径 */
NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:filePath];
NSString *recordPath = [path stringByAppendingPathComponent:[NSString stringWithFormat:@"/%@",fileName]];
//[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
if (![self creatFile:path]) {
return;
}
NSURLSessionDownloadTask *downloadTask = [manager downloadTaskWithRequest:request progress:^(NSProgress * _Nonnull downloadProgress) {
progressBlock(downloadProgress);
SSLog(@"下载进度：%.0f％", downloadProgress.fractionCompleted * 100);
} destination:^NSURL * _Nonnull(NSURL * _Nonnull targetPath, NSURLResponse * _Nonnull response) {
dispatch_async(dispatch_get_main_queue(), ^{
//如果需要进行UI操作，需要获取主线程进行操作
});
/* 设定下载到的位置 */
return [NSURL fileURLWithPath:recordPath];
} completionHandler:^(NSURLResponse * _Nonnull response, NSURL * _Nullable filePath, NSError * _Nullable error) {
if(error){
failureBlock(response,error);
}else{
successBlcok(response,filePath);
}
}];
[downloadTask resume];
}
NSFileManager常用的文件管理操作
- 创建目录 createDirectoryAtPath：
- 创建文件 createFileAtPath：
- 删除某个文件 removeItemAtPath:
- 检查某个文件是否存在 fileExistsAtPath:
- 检查文件是否可读 isReadableFileAtPath:
- 检查文件是否可写 isWritableFileAtPath:
- 取得文件属性 fileAttributesAtPath:
- 改变文件属性 changeAttributesAtPath:
- 从path代表的文件中读取数据 contentsAtPath
- 移动文件 movePath:toPath:handler:
- 复制文件 copyPath:toPath:handler: