在目录中查找照片！（以编程方式）答案

【问题标题】：Find Photo in Directory! (Programmatically)在目录中查找照片！（以编程方式）
【发布时间】：2011-08-23 15:22:33
【问题描述】：

来自stackoverflow的圣人，

我的问题：我需要发送一封包含 3 个附件的电子邮件。第一个是.txt，进展顺利，他没有问题，但问题在于图片。我用这个捕获了一个打印屏幕：

-(IBAction)screenShot{
    maintimer = [NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:@selector(update) userInfo:nil repeats:YES];
}

-(void)update{
    time = time + 1;
    if(time == 2){
        [self hideThem]; //hides the buttons
        UIGraphicsBeginImageContext(self.bounds.size);
        [self.layer renderInContext:UIGraphicsGetCurrentContext()];
        UIImage *screenImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        UIImageWriteToSavedPhotosAlbum(screenImage, nil, nil, nil);

        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"GRAPH SAVED" message:@"YOUR GRAPH HAS BEEN SAVEN IN THE PHOTO ALBUM" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [alert show];
        [alert release];
        [maintimer invalidate];
        time = 0;
    }
    [self bringThem]; //brings the buttons back

}

但现在我需要获取我创建的这个图像！我尝试使用与文本相同的代码：

-(IBAction)sendMail
{
    (..)
        //HERE IS WHERE THE NAME IS GIVEN
    NSString *filename = [NSString stringWithFormat:@"%f.txt", [[NSDate date] timeIntervalSince1970]];

        //THIS IS GOING TO STORE MY MESSAGE STUFF
    NSString *content = [[NSMutableString alloc]init];

        (...) //LOTS OF UNNECESSARY CODE

        //HERE IS WHERE IT BILDS THE FILE
    [self writeToTextFile:filename content:content];

         //HERE IS THE CODE WHERE IT ATTACHES THE FILE
    [self sendMailWithFile:filename];
    //[content release];
}

-(void)sendMailWithFile : (NSString *)file 
{
        //THIS IS THE CODE THAT GETS THE TEXT
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);   
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *fileName = [NSString stringWithFormat:@"%@/%@", documentsDirectory, file]; 
    NSData *data = [[NSData alloc] initWithContentsOfFile:fileName];


    //THIS WAS MY TRY TO GET THE PHOTO ON THE SAME STYLE OF THE TEXT              
    NSArray *photoPath = NSSearchPathForDirectoriesInDomains(NSPicturesDirectory, NSUserDomainMask, YES);
    NSString *photoDirectoryForFirstPhoto = [photoPath objectAtIndex:0];
    NSString *photoName_First = [NSString stringWithFormat:@"%@/%@", photoDirectoryForFirstPhoto, /*I DO NOT HAVE THE PHOTO NAME*/@"FirstPhoto"];
    NSData *photoData_First = [[NSData alloc] initWithContentsOfFile:photoName_First];


    MFMailComposeViewController *mailComposer = [[MFMailComposeViewController alloc] init];

    if ([MFMailComposeViewController canSendMail]) 
    {
        mailComposer = [[MFMailComposeViewController alloc] init];
        mailComposer.mailComposeDelegate = self;
        [mailComposer setSubject:@"RK4 data"];

        [mailComposer addAttachmentData:data mimeType:@"text/plain" fileName:@"[RK4][EQUATION][TEXT]"];
        [mailComposer addAttachmentData:photoData_First mimeType:@"image/png" fileName:@"[RK4][EQUATION][IMAGE]"];
        [mailComposer setMessageBody:@"iCalculus Runge-Kutta data." isHTML:NO];
        [self presentModalViewController:mailComposer animated:YES];

    }
    else (...) 

    [mailComposer release];
    [data release];

}

所以这是我的问题。我需要找到一种方法来获取我拍摄的打印屏幕并附上它。因为我需要在他单击“发送邮件”按钮后立即提供电子邮件中的所有附件。

谢谢。

【问题讨论】：

标签： iphone objective-c xcode ipod-touch

【解决方案1】：

看看here，了解如何使用 base-64 将图像直接嵌入到电子邮件中，这比将临时图像转储到用户保存的相册中要干净得多。

编辑： Category 使用 NSData 处理 base 64，请使用底部的下载。

【讨论】：

那是一个更好的方法，但是有一个小问题，就是不显示 base 64 编码。

【解决方案2】：

不要保存到你的照片库，你应该保存到documents目录，或者tmp目录，获取documents目录你可以使用以下。

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

NSString *path = [dd stringByAppendingPathComponent:@"file.png"];
[UIImagePNGRepresentation(screenImage) writeToFile:path atomically:NO];

【讨论】：