我正在开发iPhone应用程序的一项功能,它将iPhone屏幕的图像张贴到用户的Facebook墙上,但我无法正确确定图像的大小和缩放比例。当应用发布到Twitter时没有问题,但是当它发布到Facebook时,我最终只能获得更大图像的一小部分。我想要的只是屏幕图像的缩小版。如何缩放屏幕图像张贴在Facebook墙上?
下面是我使用(或试图使用)的代码:
这将创建图像。
-(UIImage *)createImage
{
CGRect newRect = CGRectMake(0, 0, [[UIScreen mainScreen] bounds].size.width, [[UIScreen mainScreen] bounds].size.height-44);
UIGraphicsBeginImageContext(newRect.size); //([self.view frame].size])
[[self.view layer] renderInContext:UIGraphicsGetCurrentContext()];
UIImage *myImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIGraphicsBeginImageContext([self.view bounds].size);
[myImage drawInRect:CGRectMake(0, 0, [[UIScreen mainScreen] bounds].size.width, [[UIScreen mainScreen] bounds].size.height-44)];
myImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return myImage;
}
而这目前无法缩放:
- (UIImage*) scaleImage:(UIImage*)image
{
int widthToUse = [[UIScreen mainScreen] bounds].size.width;
int heightToUse = [[UIScreen mainScreen] bounds].size.height;
CGSize scaledSize;
scaledSize.height = 350; //I used 350 because it seemed to be the maximum size of a Facebook wall photo.
scaledSize.width = ((350*widthToUse)/heightToUse);
UIGraphicsBeginImageContextWithOptions(scaledSize, NO, 0.0);
CGRect scaledImageRect = CGRectMake(0.0, 0.0, scaledSize.width, scaledSize.height);
[image drawInRect:scaledImageRect];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
这里是我如何使用它:
[controller setInitialText:msgText];
[controller addURL:[NSURL URLWithString:@"http://www.myURL.com"]];
UIImage *img = [self createImage];
UIImage *pic;
if (self.serviceType==SLServiceTypeFacebook)
{
pic = [self scaleImage:img];
}
else if (self.serviceType==SLServiceTypeTwitter)
{
pic = img;
}
[controller addImage:pic];
[self presentViewController:controller animated:YES completion:Nil];
我如何能解决这个问题有什么想法?
在此先感谢您的帮助。
嗯。我用0.25,0.75和2.0来试这个,而且没有一个看起来有什么区别。 :( –