diff --git a/UsefulPickerVIew.xcodeproj/project.pbxproj b/UsefulPickerVIew.xcodeproj/project.pbxproj
index d005bee..9e17cfa 100755
--- a/UsefulPickerVIew.xcodeproj/project.pbxproj
+++ b/UsefulPickerVIew.xcodeproj/project.pbxproj
@@ -261,12 +261,12 @@
 					};
 					4B0BCC101CCE6A1B0000FE60 = {
 						CreatedOnToolsVersion = 7.3;
-						LastSwiftMigration = 0810;
+						LastSwiftMigration = 0910;
 						TestTargetID = 4B0BCBFC1CCE6A1B0000FE60;
 					};
 					4B0BCC1B1CCE6A1B0000FE60 = {
 						CreatedOnToolsVersion = 7.3;
-						LastSwiftMigration = 0810;
+						LastSwiftMigration = 0910;
 						TestTargetID = 4B0BCBFC1CCE6A1B0000FE60;
 					};
 				};
@@ -476,7 +476,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.ZeroJ.UsefulPickerVIew;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Debug;
 		};
@@ -489,7 +489,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.ZeroJ.UsefulPickerVIew;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Release;
 		};
@@ -501,7 +501,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.ZeroJ.UsefulPickerVIewTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.0;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/UsefulPickerVIew.app/UsefulPickerVIew";
 			};
 			name = Debug;
@@ -514,7 +515,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.ZeroJ.UsefulPickerVIewTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.0;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/UsefulPickerVIew.app/UsefulPickerVIew";
 			};
 			name = Release;
@@ -526,7 +528,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.ZeroJ.UsefulPickerVIewUITests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.0;
 				TEST_TARGET_NAME = UsefulPickerVIew;
 			};
 			name = Debug;
@@ -538,7 +541,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.ZeroJ.UsefulPickerVIewUITests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.0;
 				TEST_TARGET_NAME = UsefulPickerVIew;
 			};
 			name = Release;
diff --git a/UsefulPickerView/Source/PickerView.swift b/UsefulPickerView/Source/PickerView.swift
index 3500409..bdc7133 100755
--- a/UsefulPickerView/Source/PickerView.swift
+++ b/UsefulPickerView/Source/PickerView.swift
@@ -357,7 +357,7 @@ open class PickerView: UIView {
             addSubview(pickerView)
         }
     }
-    func dateDidChange(_ datePic: UIDatePicker) {
+    @objc func dateDidChange(_ datePic: UIDatePicker) {
         selectedDate = datePic.date
     }
     
diff --git a/UsefulPickerView/Source/SelectionTextField.swift b/UsefulPickerView/Source/SelectionTextField.swift
index 3a01ce7..b663582 100755
--- a/UsefulPickerView/Source/SelectionTextField.swift
+++ b/UsefulPickerView/Source/SelectionTextField.swift
@@ -65,7 +65,7 @@ open class SelectionTextField: UITextField {
 }
 
 // MARK: - 监听通知
-extension SelectionTextField {
+@objc extension SelectionTextField {
     
     fileprivate func commonInit() {
         NotificationCenter.default.addObserver(self, selector: #selector(self.didBeginEdit), name: NSNotification.Name.UITextFieldTextDidBeginEditing, object: self)
diff --git a/UsefulPickerView/Source/ToolBarView.swift b/UsefulPickerView/Source/ToolBarView.swift
index 42a7014..09a3b54 100755
--- a/UsefulPickerView/Source/ToolBarView.swift
+++ b/UsefulPickerView/Source/ToolBarView.swift
@@ -94,14 +94,6 @@ open class ToolBarView: UIView {
         cancleBtn.addTarget(self, action: #selector(self.cancelBtnOnClick(_:)), for: .touchUpInside)
     }
     
-    func doneBtnOnClick(_ sender: UIButton) {
-        doneAction?()
-    }
-    func cancelBtnOnClick(_ sender: UIButton) {
-        cancelAction?()
-        
-    }
-    
     override open func layoutSubviews() {
         super.layoutSubviews()
         let margin = 15.0
@@ -120,3 +112,13 @@ open class ToolBarView: UIView {
     
     
 }
+
+@objc extension ToolBarView {
+    func doneBtnOnClick(_ sender: UIButton) {
+        doneAction?()
+    }
+    func cancelBtnOnClick(_ sender: UIButton) {
+        cancelAction?()
+        
+    }
+}
diff --git a/UsefulPickerView/Source/UsefulPickerView.swift b/UsefulPickerView/Source/UsefulPickerView.swift
index 2741df9..631b68e 100755
--- a/UsefulPickerView/Source/UsefulPickerView.swift
+++ b/UsefulPickerView/Source/UsefulPickerView.swift
@@ -187,7 +187,7 @@ open class UsefulPickerView: UIView {
 }
 
 // MARK:- selector
-extension UsefulPickerView {
+@objc extension UsefulPickerView {
     
     fileprivate func addOrentationObserver() {
         NotificationCenter.default.addObserver(self, selector: #selector(self.statusBarOrientationChange), name: NSNotification.Name.UIApplicationDidChangeStatusBarOrientation, object: nil)