增加保留几位小数接口

Author: Eric Wu

CRBoostSwift/Classes/Foundation+CRBoost.swift

@@ -124,6 +124,22 @@ extension String {
         return result
     }
 
+    @discardableResult
+    public func retainDecimal(_ digits: Int) -> String {
+        let formatter = NumberFormatter()
+        formatter.numberStyle = .decimal
+        formatter.minimumFractionDigits = digits
+        formatter.usesGroupingSeparator = false
+        var decimal = NSDecimalNumber(string: isEmpty ? "0" : self)
+        if decimal.decimalValue == .nan {
+            decimal = NSDecimalNumber(string: "0")
+        }
+        if let value = formatter.string(for: decimal) {
+            return value
+        }
+        return "0"
+    }
+
     @discardableResult
     public func randomStringLength(len: Int) -> String {
         let randomCharacters = (0 ..< len).map { _ in self.randomElement()! }
@@ -751,7 +767,7 @@ extension UIImage {
             let context = CIContext(options: nil)
             if let bitmapImage = context.createCGImage(output, from: output.extent) {
                 // 4. 显示二维码
-                let newImage =  UIImage(cgImage: bitmapImage, scale: UIScreen.main.scale, orientation: UIImage.Orientation.up)
+                let newImage = UIImage(cgImage: bitmapImage, scale: UIScreen.main.scale, orientation: UIImage.Orientation.up)
                 return newImage
             }
         }

Example/CRBoostSwift/ViewController.swift

@@ -19,12 +19,11 @@ class ViewController: UIViewController {
     }
 
     override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
-        let rect = CGRect(x: 25, y: 20, width: 100, height: 100)
-        print("midX\(rect.midX),midY:\(rect.midY)")
-        print(CRFrameCenter(rect: rect))
-        btnAdd.centerX = view.centerX
-        btnAdd.centerY = view.centerY
-        print(CRIdfa)
+//        print("a".retainDecimal(5))
+//        print("1".retainDecimal(5))
+//        print(".11".retainDecimal(5))
+//        print(".".retainDecimal(5))
+        print("".retainDecimal(5))
 
     }
 }