xcode - 如何在 Xcode 中保存和加载图片

Question

如果你真的不明白，请检查我的应用程序（快速笔记！）但它就在这里。我的应用程序是一个笔记应用程序，因此它允许用户从下面几种不同的笔记颜色和设计中进行选择。当用户选择一个时，它会将上面的注释更改为他们设置的任何内容。所以我需要一个按钮来保存他们选择的图片，当离开视图并返回时，他们可以单击加载按钮，他们选择的相同图像将出现。我正在使用 Xcode 4.3。

Answer 1

NSImageView 是你要找的。

• 这包含有关保存文件的信息（用代码查看答案）：实现从 NSImageView 拖动并将图像保存到文件

编码：

-(IBAction)saveImageButtonPushed:(id)sender
{
     NSBitmapImageRep *rep;
     NSData *data;
     NSImage *image;

     [self lockFocus];
     rep = [[NSBitmapImageRep alloc] initWithFocusedViewRect:[self frame]];
     [self unlockFocus];

     image = [[[NSImage alloc] initWithSize:[rep size]] autorelease];
     [image addRepresentation:rep];

     data = [rep representationUsingType: NSPNGFileType properties: nil];
     //save as png but failed
     [data writeToFile: @"asd.png" atomically: NO];

     //save as pdf, succeeded but with flaw
     data = [self dataWithPDFInsideRect:[self frame]];
     [data writeToFile:@"asd.pdf" atomically:YES];
}
//......
@end

• 要加载图像：

  编码：

  NSImage loadedImage = [[NSImage alloc] initWithContentsOfFile: NSString* filePath]
  

Answer 2

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"yyyyMMddHHmmss"];
NSDate *date = [[NSDate date] dateByAddingTimeInterval:1];
profile_img = [NSString stringWithFormat:@"%@.png",[dateFormatter stringFromDate:date]];
[profile_img retain];

NSLog(@"formattedDateString: %@",profile_img);

NSData *imageToUpload = UIImagePNGRepresentation(Img_View.image);
AFHTTPClient *client= [AFHTTPClient clientWithBaseURL:[NSURL URLWithString:ServerPath]];

NSMutableURLRequest *request = [client multipartFormRequestWithMethod:@"POST" path:@"Upload.php" parameters:nil constructingBodyWithBlock: ^(id <AFMultipartFormData>formData) {
    [formData appendPartWithFileData: imageToUpload name:@"file" fileName:profile_img mimeType:@"image/png"];
}];

AFHTTPRequestOperation *operation2 = [[AFHTTPRequestOperation alloc] initWithRequest:request];

[operation2 setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation2, id responseObject)
 {

     NSString *response = [operation2 responseString];
     NSLog(@"response: [%@]",response);

     NSString *post = [NSString stringWithFormat:@"Images=%@",profile_img];

     NSData *postData = [post dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:NO];
     NSString *postLength = [NSString stringWithFormat:@"%d", [post length]];

     NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:@"%@Gallery.php",ServerPath]];
     NSMutableURLRequest *request1 = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
     [request1 setHTTPMethod:@"POST"];
     NSLog(@"%@", post);
     [request1 setValue:postLength forHTTPHeaderField:@"Content-Length"];
     [request1 setHTTPBody:postData];

     NSData *returnData = [NSURLConnection sendSynchronousRequest:request1 returningResponse:nil error:nil];

     NSString    *responseString = [[[NSString alloc] initWithData:returnData
                                                          encoding:NSUTF8StringEncoding] autorelease];
     responseString = [responseString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];

     NSLog(@"%@",responseString);

     if([responseString isEqualToString:@"Entered data successfully"])
     {
         UIAlertView *Alert=[[UIAlertView alloc]initWithTitle:@"Image Share" message:@"Image Share SuccessFully" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:Nil, nil];
         [Alert show];
         [Alert release];
     }
     else
     {
     }


 } failure:^(AFHTTPRequestOperation *operation2, NSError *error) {

     NSLog(@"error: %@", [operation2 error]);

 }];

[operation2 start];