從Xcode的SpriteKit Node/SpriteNode創建一個PNG圖像爲Mac

Question

目前我正在製作一個等角地圖編輯器（在斯威夫特），其中每個地圖塊添加到SKNode稱爲mapLayer。我想知道一旦完成地圖的設計，是否可以從這個mapLayer中生成一個png圖像？

Answer 1

不是在Swift中，但它應該給你一個關於如何去做的好主意。

你可以這樣做捕獲屏幕到一個UIImage：

CGRect bounds = self.scene.view.bounds; 
UIGraphicsBeginImageContextWithOptions(bounds.size, NO, [UIScreen mainScreen].scale); 
[self drawViewHierarchyInRect:bounds afterScreenUpdates:YES]; 
UIImage* screenshotImage = UIGraphicsGetImageFromCurrentImageContext(); 
UIGraphicsEndImageContext(); 

然後創建一個從UIImage的PNG圖像（並將其寫入到磁盤）是這樣的：

// Create paths to output images 
NSString *pngPath = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/Test.png"]; 
NSString *jpgPath = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/Test.jpg"]; 

來源here 。

// Write a UIImage to JPEG with minimum compression (best quality) 
// The value 'image' must be a UIImage object 
// The value '1.0' represents image compression quality as value from 0.0 to 1.0 
[UIImageJPEGRepresentation(image, 1.0) writeToFile:jpgPath atomically:YES]; 

// Write image to PNG 
[UIImagePNGRepresentation(image) writeToFile:pngPath atomically:YES]; 

// Let's check to see if files were successfully written... 

// Create file manager 
NSError *error; 
NSFileManager *fileMgr = [NSFileManager defaultManager]; 

// Point to Document directory 
NSString *documentsDirectory = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"]; 

// Write out the contents of home directory to console 
NSLog(@"Documents directory: %@", [fileMgr contentsOfDirectoryAtPath:documentsDirectory error:&error]); 

來源here。

Answer 2

下面是如何將視圖內容寫入PNG文件的示例。首先，定義一個UIView擴展，捕獲視圖的內容並將其轉換爲UIImage。

extension UIView { 
    func screenGrab() -> UIImage { 
     // Uncomment this (and comment out the next statement) for retina screen capture 
     // UIGraphicsBeginImageContextWithOptions(bounds.size, false, UIScreen.mainScreen().scale) 
     UIGraphicsBeginImageContextWithOptions(bounds.size, false, 1.0) 
     drawViewHierarchyInRect(self.bounds, afterScreenUpdates: true) 
     let image = UIGraphicsGetImageFromCurrentImageContext() 
     UIGraphicsEndImageContext() 
     return image 
    } 
} 

然後，定義一個將UIImage寫入文件的UIImage擴展。

extension UIImage { 
    func writeToFile(fileName:String) { 
     let path = NSHomeDirectory().stringByAppendingPathComponent("Documents/"+fileName) 
     UIImagePNGRepresentation(self).writeToFile(path, atomically: true) 
    } 
} 

最後，採集和

self.view?.screenGrab().writeToFile("capture.png") 

寫視圖爲PNG文件的內容，這裏是如何確定的PNG圖像將被存儲：

println(NSHomeDirectory().stringByAppendingPathComponent("Documents"))