iOS 图片压缩以及保存到doucument的方法

#pragma mark - image_To_Samll

-(UIImage*)imageWithImageSimple:(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;

}

#pragma mark 保存图片到document

- (void)saveImage:(UIImage *)tempImage WithName:(NSString *)imageName

{

    NSData* imageData = UIImagePNGRepresentation(tempImage);

    NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);

    NSString* documentsDirectory = [paths objectAtIndex:0];

    // Now we get the full path to the file

    NSString* fullPathToFile = [documentsDirectorystringByAppendingPathComponent:imageName];

    // and then we write it out

 }