IOS webview在线预览文件图片等

亲测可以打开word文档（doc docx，ppt pptx，pdf等）图片等。

在h头文件中引用和声明文件地址：

#import 

@property (nonatomic, retain)NSString *fileURLString;

在c文件中声明delegate:

UIWebView *openFileWebView;

打开文件方法：

self.fileURLString = @“文件url地址”;
        openFileWebView = [[UIWebView alloc]initWithFrame:CGRectMake(0, 64, self.view.frame.size.width, self.view.frame.size.height)];
        openFileWebView.delegate = self;
        [openFileWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:self.fileURLString]]];

代理方法：

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
    
    
    return YES;
}
#pragma mark - Web代理
- (void)webViewDidFinishLoad:(UIWebView *)webView
{
    NSURL *targetURL = [NSURL URLWithString:self.fileURLString];
    
    NSString *docPath = [self documentsDirectoryPath];
    NSString *pathToDownloadTo = [NSString stringWithFormat:@"%@/%@", docPath, [targetURL lastPathComponent]];
    NSFileManager *fileManager = [NSFileManager defaultManager];
    BOOL hasDownLoad= [fileManager fileExistsAtPath:pathToDownloadTo];
    if (hasDownLoad) {
        self.fileURL = [NSURL fileURLWithPath:pathToDownloadTo];
        QLPreviewController *qlVC = [[QLPreviewController alloc]init];
        qlVC.delegate = self;
        qlVC.dataSource = self;
        [self.navigationController pushViewController:qlVC animated:YES];
        //
    }
    else {
        NSURL *targetURL = [NSURL URLWithString:self.fileURLString];
        
        NSData *fileData = [[NSData alloc] initWithContentsOfURL:targetURL];
        // Get the path to the App's Documents directory
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        NSString *documentsDirectory = [paths objectAtIndex:0]; // Get documents folder
        [fileData writeToFile:[NSString stringWithFormat:@"%@/%@", documentsDirectory, [targetURL lastPathComponent]] atomically:YES];
        NSURLRequest *request = [NSURLRequest requestWithURL:targetURL];
        [openFileWebView loadRequest:request];
    }
    
    NSLog(@"webViewDidFinishLoad");
}

- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error
{
    NSLog(@"didFailLoadWithError");
    
    
}

- (NSInteger)numberOfPreviewItemsInPreviewController:(QLPreviewController *)controller {
    return 1;
}

- (id )previewController:(QLPreviewController *)controller previewItemAtIndex:(NSInteger)index {
    return self.fileURL;
}

- (void)previewControllerWillDismiss:(QLPreviewController *)controller {
    NSLog(@"previewControllerWillDismiss");
}

- (void)previewControllerDidDismiss:(QLPreviewController *)controller {
    NSLog(@"previewControllerDidDismiss");
}

- (BOOL)previewController:(QLPreviewController *)controller shouldOpenURL:(NSURL *)url forPreviewItem:(id )item{
    return YES;
}

- (CGRect)previewController:(QLPreviewController *)controller frameForPreviewItem:(id )item inSourceView:(UIView * __nullable * __nonnull)view{
    return CGRectZero;
}

- (NSString *)documentsDirectoryPath {
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectoryPath = [paths objectAtIndex:0];
    return documentsDirectoryPath;
}