iOS文件预览的几种方式

有时候由于项目开发的需要，我们需要预览本地的文件（word、Excel、pdf等）。

例如：

那么其实现方式有哪些呢？

iOS的文件预览主要有以下三种方式。

一、UIDocumentInteractionController

 //本地文件的绝对路径
 NSString *path = [[NSBundle mainBundle] pathForResource:@"测试" ofType:@"docx"];
 NSURL *url = [NSURL fileURLWithPath:path];

 UIDocumentInteractionController *interactionController = [UIDocumentInteractionController interactionControllerWithURL:url];
 interactionController.delegate = self;

 //预览有其他软件打开按钮
 [interactionController presentPreviewAnimated:NO];

 CGRect navRect = self.navigationController.navigationBar.frame;
 navRect.size =CGSizeMake(1500.0f,40.0f);

 //直接显示包含预览的菜单项
 [interactionController presentOpenInMenuFromRect:navRect inView:self.view animated:YES];

我们设置了interactionController.delegate = self;就要实现UIDocumentInteractionControllerDelegate中其相应的代理方法

-(UIViewController *)documentInteractionControllerViewControllerForPreview:(UIDocumentInteractionController *)controller{
return self;
}
-(UIView *)documentInteractionControllerViewForPreview:(UIDocumentInteractionController *)controller{
return self.view;
}
-(CGRect)documentInteractionControllerRectForPreview:(UIDocumentInteractionController *)controller{
return  self.view.frame;
}

command+R，我们就能看到实现效果了

二、quickLook

quickLook也是系统提供的
首先导入#import

    QLPreviewController *qlController = [[QLPreviewController alloc]init];
    qlController.delegate = self;
    qlController.dataSource = self;
    [qlController setCurrentPreviewItemIndex:0];
    [self presentViewController:qlController animated:YES completion:nil];

接下来实现QLPreviewControllerDelegate,QLPreviewControllerDataSource中的相关方法：

/*!
* @abstract Returns the number of items that the    preview controller should preview.
* @param controller The Preview Controller.
* @result The number of items.
*/
- (NSInteger)numberOfPreviewItemsInPreviewController:(QLPreviewController *)controller{
return 1;
}

/*!
 * @abstract Returns the item that the preview controller should preview.
* @param controller The Preview Controller.
* @param index The index of the item to preview.
* @result An item conforming to the QLPreviewItem protocol.
*/
- (id )previewController:(QLPreviewController *)controller previewItemAtIndex:(NSInteger)index{
NSString *path = [[NSBundle mainBundle] pathForResource:@"测试" ofType:@"docx"];
NSURL *url = [NSURL fileURLWithPath:path];
return url;
}

这样，就能实现文件的预览了

三.UIWebView / WKWebView

现以webView为例，来实现文件预览，我具体实现细节如下：

_webView.delegate = self;
_webView.multipleTouchEnabled = YES;
_webView.scalesPageToFit = YES;
_webView.scrollView.bounces = NO;
NSStringEncoding *useEncodeing = nil;
NSString *path = [[NSBundle mainBundle] pathForResource:@"测试" ofType:@"docx"];
NSString *body = [NSString stringWithContentsOfFile:path encoding:(long)useEncodeing error:nil];
if (body) {

    body =[body stringByReplacingOccurrencesOfString:@"\n" withString:@"
"];//替换换行符为HTML换行符

    [_webView loadHTMLString:body baseURL:[NSURL fileURLWithPath:path]];

}else { //其他文件直接加载请求

    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL fileURLWithPath:path]];
    [_webView loadRequest:request];
}

webView加载完成调用：

- (void)webViewDidFinishLoad:(UIWebView *)webView

{
//获取加载的h5字符串的body

NSString *lJs = @"document.documentElement.innerText";//获取当前网页的html

NSString *currentHTMLBody = [webView stringByEvaluatingJavaScriptFromString:lJs];

if ([currentHTMLBody isEqualToString:@""]) { //不能预览

    //做一些不能预览的处理操作
}
}