【小笔记】图片压缩、上传，图库操作

1、图片压缩 

 用法：UIImage *yourImage= [self imageWithImageSimple:image scaledToSize:CGSizeMake(210.0, 210.0)];
 //压缩图片
 - (UIImage*)imageWithImageSimple:(UIImage*)image scaledToSize:(CGSize)newSize
 {
     // Create a graphics image context
     UIGraphicsBeginImageContext(newSize);
     // Tell the old image to draw in this newcontext, with the desired
     // new size
     [image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
     // Get the new image from the context
     UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
     // End the context
     UIGraphicsEndImageContext();
     // Return the new image.
     return newImage;
 }

2、图片上传代码

 

 - (IBAction)uploadButton:(id)sender {
     UIImage *image = [UIImage imageNamed:@"1.jpg"]; //图片名
     NSData *imageData = UIImageJPEGRepresentation(image,0.5);//压缩比例
     NSLog(@"字节数:%i",[imageData length]);
     // post url
     NSString *urlString = @"http://192.168.1.113:8090/text/UploadServlet";
     //服务器地址
     // setting up the request object now
     NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init] ;
     [request setURL:[NSURL URLWithString:urlString]];
     [request setHTTPMethod:@"POST"];
     //
     NSString *boundary = [NSString stringWithString:@"---------------------------14737809831466499882746641449"];
     NSString *contentType = [NSString stringWithFormat:@"multipart/form-data;boundary=%@",boundary];
     [request addValue:contentType forHTTPHeaderField: @"Content-Type"];
     //
     NSMutableData *body = [NSMutableData data];
     [body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
     [body appendData:[[NSString stringWithString:@"Content-Disposition:form-data; name=\"userfile\"; filename=\"2.png\"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]]; //上传上去的图片名字
     [body appendData:[[NSString stringWithString:@"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
     [body appendData:[NSData dataWithData:imageData]];
     [body appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
     [request setHTTPBody:body];
     // NSLog(@"1-body:%@",body);
     NSLog(@"2-request:%@",request);
     NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
     NSString *returnString = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding];
     NSLog(@"3-测试输出：%@",returnString);
     15.给imageView加载图片
     UIImage *myImage = [UIImage imageNamed:@"1.jpg"];
     [imageView setImage:myImage];
     [self.view addSubview:imageView];

3、对图库的操作 

   //选择相册：
     UIImagePickerControllerSourceTypesourceType=UIImagePickerControllerSourceTypeCamera;
     if (![UIImagePickerControllerisSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
         sourceType=UIImagePickerControllerSourceTypePhotoLibrary;
     }
     UIImagePickerController * picker = [[UIImagePickerControlleralloc]init];
     picker.delegate = self;
     picker.allowsEditing=YES;
     picker.sourceType=sourceType;
     [self presentModalViewController:picker animated:YES];
     //选择完毕：
     -(void)imagePickerController:(UIImagePickerController*)pickerdidFinishPickingMediaWithInfo:(NSDictionary *)info
     {
         [picker dismissModalViewControllerAnimated:YES];
         UIImage * image=[info objectForKey:UIImagePickerControllerEditedImage];
         [self performSelector:@selector(selectPic:) withObject:imageafterDelay:0.1];
     }
     -(void)selectPic:(UIImage*)image
     {
         NSLog(@"image%@",image);
         imageView = [[UIImageView alloc] initWithImage:image];
         imageView.frame = CGRectMake(0, 0, image.size.width, image.size.height);
         [self.viewaddSubview:imageView];
         [self performSelectorInBackground:@selector(detect:) withObject:nil];
     }
     //detect为自己定义的方法，编辑选取照片后要实现的效果
    // 取消选择：
     -(void)imagePickerControllerDIdCancel:(UIImagePickerController*)picker
     {
         [picker dismissModalViewControllerAnimated:YES];
     }