数据不会保存到桌面

Question

我正试图从解析通过模拟器中提取一个PDF文件，并保存到我的桌面上，当我的应用程序上的一个按钮被点击时。问题是，无论我做什么，文件不会出现在桌面或其他任何地方。我正在对下载按钮使用此方法

-(void) Savefile {
    NSFileManager *filemanager = [NSFileManager defaultManager];
    [self.downloadfile getDataInBackgroundWithBlock:^(NSData *data, NSError *error) {
        if (error)  {

        }
        else if (data) {
            [filemanager createFileAtPath:@"file:///Users/Danny/Desktop" contents:data attributes:nil];
            [data writeToFile:@"file:///Users/Danny/Desktop" atomically:NO ];
            NSLog(@"Downloading file...");
        }
    }];

}

@property (retain,nonatomic) PFFile * downloadfile;

detailVC.downloadfile=[[PDFArray objectAtIndex:indexPath.row]objectForKey:@"PDFFile"];

无法将其保存到桌面。

Answer 1

您正在尝试下载Pdf文件的路径在iOS设备中不存在，如果您想在您的设备中下载文件，您可以这样尝试：-

-(void) Savefile {

    [self.downloadfile getDataInBackgroundWithBlock:^(NSData *data, NSError *error) {
        if (error)
        {
            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Wooopss!" message:@"Download failed. Try Again..." delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
            [alert show];
        }
        else if (data)
        {
            NSString *downloadFilePath = [NSString stringWithFormat:@"%@/Documents/PDFFile/hello_%@.pdf", NSHomeDirectory(),[self getCurrentDate]];

            if( ![[NSFileManager defaultManager] fileExistsAtPath:downloadFilePath] )
            {
                NSLog(@"File don't exist at that path");
            }
            else
            {
                NSError *error = nil;
                [[NSFileManager defaultManager] removeItemAtPath:downloadFilePath error:&error];
            }

            [[NSFileManager defaultManager] createFileAtPath:downloadFilePath contents:nil attributes:nil];

            NSLog(@"Downloading file...");

            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Downloading" message:@"File is being downloaded..." delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
            [alert show];
        }
    }];

}
//Below method will return you current timestamp through which you can download new PDF with new name

-(NSString *)getCurrentDate
{

    NSDateFormatter *dateFormatter = [NSDateFormatter new];
    [dateFormatter setDateFormat:@"MMddYYYYmmss"];

    NSString *date = [dateFormatter stringFromDate:[NSDate date]];

    return date;
}

希望这能帮助你快乐编码：）