diff --git a/Classes/WDCropBorderView.swift b/Classes/WDCropBorderView.swift
index ef985c1..2ff3d3a 100644
--- a/Classes/WDCropBorderView.swift
+++ b/Classes/WDCropBorderView.swift
@@ -27,16 +27,16 @@ internal class WDCropBorderView: UIView {
     override func drawRect(rect: CGRect) {
         let context = UIGraphicsGetCurrentContext()
 
-        CGContextSetStrokeColorWithColor(context,
+        CGContextSetStrokeColorWithColor(context!,
             UIColor(red: 1, green: 1, blue: 1, alpha: 0.5).CGColor)
-        CGContextSetLineWidth(context, 1.5)
-        CGContextAddRect(context, CGRectMake(kHandleDiameter / 2, kHandleDiameter / 2,
+        CGContextSetLineWidth(context!, 1.5)
+        CGContextAddRect(context!, CGRectMake(kHandleDiameter / 2, kHandleDiameter / 2,
             rect.size.width - kHandleDiameter, rect.size.height - kHandleDiameter))
-        CGContextStrokePath(context)
+        CGContextStrokePath(context!)
 
-        CGContextSetRGBFillColor(context, 1, 1, 1, 0.95)
+        CGContextSetRGBFillColor(context!, 1, 1, 1, 0.95)
         for handleRect in calculateAllNeededHandleRects() {
-            CGContextFillEllipseInRect(context, handleRect)
+            CGContextFillEllipseInRect(context!, handleRect)
         }
     }
 
@@ -66,4 +66,4 @@ internal class WDCropBorderView: UIView {
         return [topLeft, topCenter, topRight, middleRight, bottomRight, bottomCenter, bottomLeft,
             middleLeft]
     }
-}
\ No newline at end of file
+}
diff --git a/Classes/WDImageCropView.swift b/Classes/WDImageCropView.swift
index 7158dfe..c248518 100644
--- a/Classes/WDImageCropView.swift
+++ b/Classes/WDImageCropView.swift
@@ -187,7 +187,7 @@ internal class WDImageCropView: UIView, UIScrollViewDelegate {
         visibleRect = CGRectApplyAffineTransform(visibleRect, rectTransform);
 
         // finally crop image
-        let imageRef = CGImageCreateWithImageInRect(imageToCrop!.CGImage, visibleRect)
+        let imageRef = CGImageCreateWithImageInRect(imageToCrop!.CGImage!, visibleRect)
         let result = UIImage(CGImage: imageRef!, scale: imageToCrop!.scale,
             orientation: imageToCrop!.imageOrientation)
 
@@ -256,4 +256,4 @@ internal class WDImageCropView: UIView, UIScrollViewDelegate {
 
         return CGAffineTransformScale(rectTransform, image.scale, image.scale)
     }
-}
\ No newline at end of file
+}
diff --git a/Classes/WDImageCropViewController.swift b/Classes/WDImageCropViewController.swift
index b244791..d7b0e7d 100644
--- a/Classes/WDImageCropViewController.swift
+++ b/Classes/WDImageCropViewController.swift
@@ -53,7 +53,7 @@ internal class WDImageCropViewController: UIViewController {
     }
 
     func actionCancel(sender: AnyObject) {
-        self.navigationController?.popViewControllerAnimated(true)
+        self.dismissViewControllerAnimated(true, completion: nil)
     }
 
     func actionUse(sender: AnyObject) {
@@ -64,7 +64,7 @@ internal class WDImageCropViewController: UIViewController {
     private func setupNavigationBar() {
         self.navigationItem.leftBarButtonItem = UIBarButtonItem(barButtonSystemItem: .Cancel,
                                                                 target: self, action: #selector(actionCancel))
-        self.navigationItem.leftBarButtonItem = UIBarButtonItem(title: "Use", style: .Plain,
+        self.navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Use", style: .Plain,
             target: self, action: #selector(actionUse))
     }
 
@@ -107,13 +107,13 @@ internal class WDImageCropViewController: UIViewController {
         let colorSpace = CGColorSpaceCreateDeviceRGB()
         let gradient = CGGradientCreateWithColorComponents(colorSpace, components, nil, 2)
 
-        CGContextDrawLinearGradient(context, gradient, CGPointMake(0, 0), CGPointMake(0, 54), [])
+        CGContextDrawLinearGradient(context!, gradient!, CGPointMake(0, 0), CGPointMake(0, 54), [])
 
         let viewImage = UIGraphicsGetImageFromCurrentImageContext()
 
         UIGraphicsEndImageContext()
 
-        return viewImage
+        return viewImage!
     }
 
     private func setupToolbar() {
diff --git a/WDImagePicker.xcodeproj/project.pbxproj b/WDImagePicker.xcodeproj/project.pbxproj
index be612e5..b9bae84 100644
--- a/WDImagePicker.xcodeproj/project.pbxproj
+++ b/WDImagePicker.xcodeproj/project.pbxproj
@@ -189,9 +189,11 @@
 				TargetAttributes = {
 					764FD5801B8F01C100BE5F46 = {
 						CreatedOnToolsVersion = 6.4;
+						LastSwiftMigration = 0800;
 					};
 					764FD5951B8F01C100BE5F46 = {
 						CreatedOnToolsVersion = 6.4;
+						LastSwiftMigration = 0800;
 						TestTargetID = 764FD5801B8F01C100BE5F46;
 					};
 				};
@@ -381,6 +383,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.wudi.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_VERSION = 2.3;
 			};
 			name = Debug;
 		};
@@ -392,6 +395,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.wudi.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_VERSION = 2.3;
 			};
 			name = Release;
 		};
@@ -408,6 +412,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.wudi.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_VERSION = 2.3;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/WDImagePicker.app/WDImagePicker";
 			};
 			name = Debug;
@@ -421,6 +426,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.wudi.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_VERSION = 2.3;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/WDImagePicker.app/WDImagePicker";
 			};
 			name = Release;