如何将我的 Zip 文件转换为 NSData 以将我的 Zip 文件作为附件通过电子邮件发送

Question

我正在使用 Objective Zip 库来压缩我拍摄的几张图像。我（我猜）已经到了压缩图像的地步了。

现在我想用邮件编辑器发送这个压缩文件。但是我需要在我的邮件函数中声明一个“NSData 对象”。

[picker addAttachmentData:"NSData object" mimeType:@"application/zip" fileName:@"test.zip"];

这是我的代码片段，

-(IBAction)sendMail{
    NSArray * paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
    NSString *documentsDirectory = [paths objectAtIndex:0];

    NSString *path = [documentsDirectory stringByAppendingPathComponent:@"test.zip"]; 
    NSArray *data = [[NSArray alloc] initWithObjects:@"first",@"second",@"third",nil];

    NSString *docDir3 = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    NSString *pngFilePath4 = [NSString stringWithFormat:@"%@/foto2.jpg",paths];
    [data writeToFile:pngFilePath4 atomically:YES];

    NSData * fotoData = [[NSData alloc] initWithContentsOfFile:pngFilePath4];

    NSFileManager *manager = [[NSFileManager alloc] init]; 
    [manager removeItemAtPath:pngFilePath4 error:nil];

    ZipFile *readFile = [[ZipFile alloc] initWithFileName:path mode:ZipFileModeCreate];

    ZipWriteStream *stream = [readFile writeFileInZipWithName:@"foto2.jpg" compressionLevel:ZipCompressionLevelNone];

    [stream writeData:fotoData];
    [stream finishedWriting];

    MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];
    picker.mailComposeDelegate=self;

    [picker addAttachmentData:"NSData Object" mimeType:@"application/zip" fileName:@"test.zip"];

    Class mailclass = (NSClassFromString(@"MFMailComposeViewController"));
    if([mailclass canSendMail]){
        [self presentModalViewController:picker animated:YES];
    }

    [readFile close];
    [data2 release];
    [fotoData release];
}

我认为我需要从 readFile 对象创建另一个 NSData 对象，并将其放置在 [picker AttachmentData: 方法] 中。希望有人能指出我正确的方向。

编辑

仍然无法使其正常工作。发送 zip 文件需要很长时间（即使通过 WiFi）。当我打开 zip 图像时，出现错误，提示该文件无法打开。这是我的代码：

NSArray * paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
    NSString *documentsDirectory = [paths objectAtIndex:0];

    NSString *path = [documentsDirectory stringByAppendingPathComponent:@"test.zip"]; 
    NSArray *data = [[NSArray alloc] initWithObjects:@"first",@"second", nil];

    NSString *docDir3 = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]; 
    NSString *pngFilePath3 = [NSString stringWithFormat:@"%@/foto2.jpeg",docDir3];
    NSData * imageData2 = [[[NSData alloc] initWithContentsOfFile:pngFilePath3] autorelease];

    [data writeToFile:pngFilePath3 atomically:YES];

    ZipFile *readFile = [[ZipFile alloc] initWithFileName:path mode:ZipFileModeCreate];

    ZipWriteStream *stream = [readFile writeFileInZipWithName:@"foto2.jpeg" compressionLevel:ZipCompressionLevelNone];

    [stream writeData:imageData2];
    [stream finishedWriting];


    MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];
    picker.mailComposeDelegate=self;
   [picker addAttachmentData:[NSData dataWithContentsOfFile:path] mimeType:@"application/zip" fileName:@"test.zip"];

    Class mailclass = (NSClassFromString(@"MFMailComposeViewController"));
    if([mailclass canSendMail]){
        [self presentModalViewController:picker animated:YES];
    }

    [data release];
    [readFile close];

提前感谢您帮助我！

Answer 1

ZipWriteStream 正在写入 path，并使用 [NSData dataWithContentsOfFile:path] 从文件路径获取数据。

[picker addAttachmentData:[NSData dataWithContentsOfFile:path] 
                 mimeType:@"application/zip" 
                 fileName:@"test.zip"];

当发生写入失败时，Objective-Zip 确实会抛出异常，因此请确保在写入操作周围添加 try/catch 并确保数据不为零。