IOS 图片上传处理 图片压缩 图片处理

提到从摄像头/相册获取图片是面向终端用户的，由用户去浏览并选择图片为程序使用。在这里，我们需要过UIImagePickerController类来和用户交互。
使用UIImagePickerController和用户交互，我们需要实现2个协议<UIImagePickerControllerDelegate,UINavigationControllerDelegate>。
View Code
代码如下复制代码
pragma mark 从用户相册获取活动图片

(void)pickImageFromAlbum

{

imagePicker = [[UIImagePickerController alloc] init];

imagePicker.delegate =self;

imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

imagePicker.modalTransitionStyle = UIModalTransitionStyleCoverVertical;

imagePicker.allowsEditing =YES;



[self presentModalViewController:imagePicker animated:YES];


}
我们来看看上面的从相册获取图片，我们首先要实例化UIImagePickerController对象，然后设置imagePicker对象为当前对象，设置imagePicker的图片来源为UIImagePickerControllerSourceTypePhotoLibrary，表明当前图片的来源为相册，除此之外还可以设置用户对图片是否可编辑。
View Code
代码如下复制代码
pragma mark 从摄像头获取活动图片

(void)pickImageFromCamera

{

imagePicker = [[UIImagePickerController alloc] init];

imagePicker.delegate =self;

imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;

imagePicker.modalTransitionStyle = UIModalTransitionStyleCoverVertical;

imagePicker.allowsEditing =YES;



[self presentModalViewController:imagePicker animated:YES];


}
//打开相机

(IBAction)touch_photo:(id)sender {
// for iphone
UIImagePickerController *pickerImage = [[UIImagePickerController alloc] init];
if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {

  pickerImage.sourceType = UIImagePickerControllerSourceTypeCamera;

  pickerImage.mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:pickerImage.sourceType];



}

pickerImage.delegate =self;

pickerImage.allowsEditing =YES;//自定义照片样式

[self presentViewController:pickerImage animated:YES completion:nil];


}
以上是从摄像头获取图片，和从相册获取图片只是图片来源的设置不一样，摄像头图片的来源为UIImagePickerControllerSourceTypeCamera。
　　　　在和用户交互之后，用户选择好图片后，会回调选择结束的方法。
-(void)imagePickerController:(UIImagePickerController)picker didFinishPickingMediaWithInfo:(NSDictionary)info
{

//初始化imageNew为从相机中获得的--

UIImage *imageNew = [info objectForKey:@"UIImagePickerControllerOriginalImage"];

//设置image的尺寸

CGSize imagesize = imageNew.size;

imagesize.height =626;

imagesize.width =413;

//对图片大小进行压缩--

imageNew = [self imageWithImage:imageNew scaledToSize:imagesize];

NSData *imageData = UIImageJPEGRepresentation(imageNew,0.00001);


if(m_selectImage==nil)

{

    m_selectImage = [UIImage imageWithData:imageData];

    NSLog(@"m_selectImage:%@",m_selectImage);

    [self.TakePhotoBtn setImage:m_selectImage forState:UIControlStateNormal];

    [picker dismissModalViewControllerAnimated:YES];

   return ;

}

[picker release];


}
//对图片尺寸进行压缩--
-(UIImage)imageWithImage:(UIImage)image scaledToSize:(CGSize)newSize
{

// Create a graphics image context

UIGraphicsBeginImageContext(newSize);



// Tell the old image to draw in this new context, 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;
}
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