从本地应用程序Documents文件夹中删除文件

Question

到目前为止，我已经设法从我的表视图中删除行，但它不会在给定的Documents文件夹中更新。 我怎么做到这一点？ 下面是我正在使用的代码。

我试图从这里实现代码如何从放在文档文件夹中的文件夹中删除文件 。

我的目标是能够删除任何文件，而不仅仅是所需的文件。

提前致谢。

#import "Documents.h"

@interface DocumentsViewController ()

@end

@implementation DocumentsViewController

- (id)initWithStyle:(UITableViewStyle)style
{
    self = [super initWithStyle:style];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    // Uncomment the following line to preserve selection between presentations.
    // self.clearsSelectionOnViewWillAppear = NO;

    // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
    self.navigationItem.rightBarButtonItem = self.editButtonItem;


    NSString *temp = [[NSBundle mainBundle] resourcePath];
    self.directoryPath = [temp stringByAppendingPathComponent:@"Documents"];

    [self.tableView setEditing:NO animated:YES];



}


- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    // Return the number of sections.
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return [directoryContents count];
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

        static NSString *CellIdentifier = @"Cell";


        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
        if (cell == nil) {
            cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
        }

        // Configure the cell.
        cell.textLabel.text = [directoryContents objectAtIndex:indexPath.row];

        return cell;
}


-(NSString*)directoryPath{
    return directoryPath;
}

-(void)setDirectoryPath:(NSString*)a{
    [a retain];
    [directoryPath release];
    directoryPath = a;
    [self loadDirectoryContents];
    [table reloadData];
}

-(void)loadDirectoryContents{
    [directoryContents release];
    directoryContents = [[NSFileManager defaultManager] directoryContentsAtPath: directoryPath];
    [directoryContents retain];
}

// Override to support conditional editing of the table view.
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Return NO if you do not want the specified item to be editable.
    return YES;
}


- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath { //implement the delegate method

    if (editingStyle == UITableViewCellEditingStyleDelete) {
        // Update data source array here, something like [array removeObjectAtIndex:indexPath.row];
        [directoryContents removeObjectAtIndex:indexPath.row];
        [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
        [tableView reloadData];


        NSString *extension = @"png";
        NSFileManager *fileManager = [NSFileManager defaultManager];
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,     NSUserDomainMask, YES);
        NSString *documentsDirectory = [paths objectAtIndex:0];

        NSArray *contents = [fileManager contentsOfDirectoryAtPath:documentsDirectory error:NULL];
        NSEnumerator *e = [contents objectEnumerator];
        NSString *filename;
        while ((filename = [e nextObject])) {

            if ([[filename pathExtension] isEqualToString:extension]) {

                [fileManager removeItemAtPath:[documentsDirectory     stringByAppendingPathComponent:filename] error:NULL];
            }
        }

    }
}


#pragma mark - Table view delegate

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Navigation logic may go here. Create and push another view controller.
    /*
     <#DetailViewController#> *detailViewController = [[<#DetailViewController#> alloc] initWithNibName:@"<#Nib name#>" bundle:nil];
     // ...
     // Pass the selected object to the new view controller.
     [self.navigationController pushViewController:detailViewController animated:YES];
     */
}

-(void)dealloc{
    [super dealloc];    
    [directoryContents release];
    directoryContents = nil;
    self.directoryPath = nil;
    [table release];
    table = nil;

}

@end

我的工作代码：

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath{
    if (editingStyle == UITableViewCellEditingStyleDelete){

        NSString *fileName = [directoryContents objectAtIndex:indexPath.row];

        NSString *path;
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        path = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"downloads"];
        path = [path stringByAppendingPathComponent:fileName];
        NSError *error;

    //Remove cell
        [directoryContents removeObjectAtIndex:indexPath.row];
        [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationLeft];
        [tableView reloadData];

        if ([[NSFileManager defaultManager] fileExistsAtPath:path])     //Does file exist?
        {
            if (![[NSFileManager defaultManager] removeItemAtPath:path error:&error])   //Delete it
            {
                NSLog(@"Delete file error: %@", error);
            }
        }
    }
}

Answer 1

NSFileManager在删除文件时非常有用：

 [[NSFileManager defaultManager] removeItemAtPath: pathToFile error: &error];

另外看看这篇文章它有一些有用的代码。 虽然有点旧，但代码工作得很好。

http://iphonedevsdk.com/forum/iphone-sdk-development/3576-how-do-i-delete-a-file-in-my-documents-directory.html

这是一些更多的代码示例

// Get the Documents directory path 
NSString *temPath = [NSString stringWithFormat:@"%@%d",@"Documents/Media_",  Key_mediaID];
//This temPath look line ../../../Documents/Media_1

  NSString *documentsDirectoryPath = [NSHomeDirectory()  stringByAppendingPathComponent:temPath]; 

// Delete the file using NSFileManager
 NSFileManager *fileManager = [NSFileManager defaultManager];
[fileManager removeItemAtPath:[documentsDirectoryPath   stringByAppendingPathComponent:Your File Name] error:nil];

这是另一个链接与一些更有用的代码

http://ios.biomsoft.com/2012/01/17/delete-all-files-in-documents-directory/

希望这可以帮助你。

编辑：

要删除具有特定扩展名的文件，例如jpg，您可以尝试以下操作

    NSString *extension = @"jpg";
    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,     NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];

    NSArray *contents = [fileManager contentsOfDirectoryAtPath:documentsDirectory error:NULL];  
    NSEnumerator *e = [contents objectEnumerator];
    NSString *filename;
    while ((filename = [e nextObject])) {

    if ([[filename pathExtension] isEqualToString:extension]) {

    [fileManager removeItemAtPath:[documentsDirectory     stringByAppendingPathComponent:filename] error:NULL];
   }
   }

除了上述内容，如果您知道要删除的文件的路径，则以下是一个有用的代码：

// Get the Documents directory path
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,   NSUserDomainMask, YES); 
NSString *documentsDirectoryPath = [paths objectAtIndex:0];

// Delete the file using NSFileManager
NSFileManager *fileManager = [NSFileManager defaultManager];
[fileManager removeItemAtPath:[documentsDirectoryPath stringByAppendingPathComponent:yourFile.txt] error:nil];

编辑2：

要删除特定文件夹中的文档：

NSError *error;
NSFileManager *fileMgr = [NSFileManager defaultManager];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,    NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *documents= [documentsDirectory  stringByAppendingPathComponent:@"YourFolder"];
NSString *filePath = [documents stringByAppendingPathComponent:@"file2.txt"];
[fileMgr removeItemAtPath:filePath error:&error]