IOS document preview function tutorial

What is the preview function of technical documents in IOS 4 SDK? Is the preview function when you print files. It is used in quicklook. Framework and supports the following file formats: iwork documents, Microsoft Office, Rich Text Format, PDF, images, text files and comma-separated (CSV) files.

Show a demo today to show its usage:

Step 1: Create a view-based project and add quicklook. framewrok

Step 2: Modify the Controller header file as follows:

#import <QuickLook/QuickLook.h> @interface TestViewController : UITableViewController <QLPreviewControllerDataSource>{  NSArray *arrayOfDocuments;} @end

Modify the Controller execution file as follows:

#import "TestViewController.h"@implementation TestViewController#pragma mark -#pragma mark Initialization/*---------------------------------------------------------------------------*  *--------------------------------------------------------------------------*/-(id)init{  if (self = [super init])  {arrayOfDocuments = [[NSArray alloc] initWithObjects: @"iOSDevTips.png", @"Remodel.xls", @"Core J2ME Technology.pdf", nil];  }  return self;}/*---------------------------------------------------------------------------*  *--------------------------------------------------------------------------*/- (void)loadView {[super loadView];[self setTitle:@"Files Available for Preview"];}#pragma mark -#pragma mark Table Management// Customize the number of sections in the table view./*---------------------------------------------------------------------------*  *--------------------------------------------------------------------------*/- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {return 1;}/*---------------------------------------------------------------------------*  *--------------------------------------------------------------------------*/- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {return [arrayOfDocuments count];}/*---------------------------------------------------------------------------*  *--------------------------------------------------------------------------*/- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {  static NSString *CellIdentifier = @"tableRow";    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];  if (cell == nil)cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];    // ???[[cell textLabel] setText:[arrayOfDocuments objectAtIndex:indexPath.row]];[cell setAccessoryType:UITableViewCellAccessoryDisclosureIndicator];return cell;}/*---------------------------------------------------------------------------*  *--------------------------------------------------------------------------*/- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {  // When user taps a row, create the preview controllerQLPreviewController *previewer = [[[QLPreviewController alloc] init] autorelease];// Set data source[previewer setDataSource:self];    // Which item to preview[previewer setCurrentPreviewItemIndex:indexPath.row];// Push new viewcontroller, previewing the document[[self navigationController] pushViewController:previewer animated:YES];}#pragma mark -#pragma mark Preview Controller/*---------------------------------------------------------------------------*  *--------------------------------------------------------------------------*/- (NSInteger) numberOfPreviewItemsInPreviewController: (QLPreviewController *) controller {return [arrayOfDocuments count];}/*---------------------------------------------------------------------------*  *--------------------------------------------------------------------------*/- (id <QLPreviewItem>)previewController: (QLPreviewController *)controller previewItemAtIndex:(NSInteger)index {// Break the path into it's components (filename and extension)NSArray *fileComponents = [[arrayOfDocuments objectAtIndex: index] componentsSeparatedByString:@"."];// Use the filename (index 0) and the extension (index 1) to get path  NSString *path = [[NSBundle mainBundle] pathForResource:[fileComponents objectAtIndex:0] ofType:[fileComponents objectAtIndex:1]];                             return [NSURL fileURLWithPath:path];}#pragma mark -#pragma mark Cleanup/*---------------------------------------------------------------------------*  *--------------------------------------------------------------------------*/- (void)dealloc {// Free up all the documents[arrayOfDocuments release];[super dealloc];}@end

Modify appdelegate as follows:

- (void)applicationDidFinishLaunching:(UIApplication *)application {     // Create and initialize the window  window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];   // Create test view controller  vc = [[TestViewController alloc] init];   // Create navigation controller   nav = [[UINavigationController alloc] initWithRootViewController:vc];   [window addSubview:[nav view]];    [window makeKeyAndVisible];}

You can find the resource file in the source code.