如何从地图视图中拍摄屏幕截图 [英] how to take a screen shot from a mapview

问题描述

在我的应用程序中，我使用了mapview.在特定的地方，我可以添加注释.我想拍摄带注解的那个地方的快照.

In my application i have used mapview. On particular place i can put annotation. i want to take the snap shot of that place with annotation in it.

我试图实现这一点.

CGSize size = self.view.bounds.size;
CGRect screensize = CGRectMake(40,40,size.width-240,size.height-400);
UIGraphicsBeginImageContext(screensize.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *screenshotImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(screenshotImage, nil, nil, nil);

UIGraphicsEndImageContext();

此代码获取捕捉，但它从(0,0)坐标获取捕捉.我想从(40,40)坐标中获取快照，图像的大小应为80 * 80.

this code takes the snap but it takes the snap from (0,0) coordinates. i want to take the snap from (40,40) coordinates and the size of the image should be 80*80.

我该怎么做?

推荐答案

我认为您不能直接做到这一点.获得整个图像并裁剪所需的区域.

I don't think you can do it directly. Get the entire image and the crop the desired region.

CGSize size = self.view.bounds.size;
CGRect cropRect = CGRectMake(40, 40, 80, 80);

/* Get the entire on screen map as Image */
UIGraphicsBeginImageContext(size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * mapImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

/* Crop the desired region */
CGImageRef imageRef = CGImageCreateWithImageInRect(mapImage.CGImage, cropRect);
UIImage * cropImage = [UIImage imageWithCGImage:imageRef]; 
CGImageRelease(imageRef);

/* Save the cropped image */
UIImageWriteToSavedPhotosAlbum(cropImage, nil, nil, nil);

UIGraphicsEndImageContext();

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