Question

我尝试用QlPreviewController显示来自互联网网址的pdf而不下载它。这是我的代码：

  NSURL* url2 = [NSURL URLWithString:@"http://wwww.myweb.com/files/terms_en.pdf"];

// Check if can be shown
if(![QLPreviewController canPreviewItem:url2]) {
    // cant show document
    NSLog(@"can't show document");
}else {
    NSLog(@"can show document");
   // Show the document in preview
  //  _previewItemURL = url;
    QLPreviewController* preview = [[QLPreviewController alloc] init];
    [preview setDataSource:url2];
}

但它没有显示任何内容。另外我在最后一句[预览setDataSource：url2]中有一个警告说'发送'NSURL * _strong'到不兼容类型'id的参数

Answer 1

根据文档，QLPreviewController需要NSFileURL，即本地文件。使用其他方式（例如NSData dataWithContentsOfURL）下载您的Web资源，写入磁盘，然后将本地URL提供给它。

Answer 2

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    QLPreviewController *previewController = [[QLPreviewController alloc] init];
    [previewController setDataSource:self];
    [previewController setDelegate:self];
    previewController.currentPreviewItemIndex = indexPath.row;
    [self presentModalViewController:previewController animated:YES];
}
- (NSInteger)numberOfPreviewItemsInPreviewController:(QLPreviewController *)controller
{
    return [self.arrayForPDFList count];
}
- (id <QLPreviewItem>)previewController:(QLPreviewController *)controller previewItemAtIndex:(NSInteger)index
{
    NSString *pathForPdf =[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
    pathForPdf = [pathForPdf stringByAppendingFormat:@"/%@.pdf",[self.arrayForPDFList objectAtIndex:index]];    
    return [NSURL URLWithString:pathForPdf];
}

来自网络节目的Pdf与QLPreviewController

2 个答案: