diff --git a/Build/Products/Debug-iphonesimulator/libdsbridge.a b/Build/Products/Debug-iphonesimulator/libdsbridge.a
index 75a3916..a4d4e3a 100644
Binary files a/Build/Products/Debug-iphonesimulator/libdsbridge.a and b/Build/Products/Debug-iphonesimulator/libdsbridge.a differ
diff --git a/README.md b/README.md
index 467b434..8d282f8 100644
--- a/README.md
+++ b/README.md
@@ -67,6 +67,8 @@ To use a dsBridge in your own project:
 1. Implement APIs in a class 
 
    ```objective-c
+   #import "dsbridge.h" 
+   ...
    @implementation JsApiTest
    //for synchronous invocation  
    - (NSString *) testSyn:(NSString *) msg
@@ -74,7 +76,7 @@ To use a dsBridge in your own project:
        return [msg stringByAppendingString:@"[ syn call]"];
    }
    //for asynchronous invocation
-   - (void) testAsyn:(NSString *) msg :(void (^)(NSString * _Nullable result,BOOL complete))completionHandler
+   - (void) testAsyn:(NSString *) msg :(JSCallback)completionHandler
    {
        completionHandler([msg stringByAppendingString:@" [ asyn call]"],YES);
    }
@@ -95,9 +97,9 @@ To use a dsBridge in your own project:
 
      ```javascript
      //cdn
-     //<script src="https://unpkg.com/dsbridge@3.1.1/dist/dsbridge.js"> </script>
+     //<script src="https://cdn.jsdelivr.net/npm/dsbridge@3.1.4/dist/dsbridge.js"> //</script>
      //npm
-     //npm install dsbridge@3.1.1
+     //npm install dsbridge@3.1.4
      var dsBridge=require("dsbridge")
      ```
 
@@ -142,7 +144,13 @@ In order to be compatible with IOS , we make the following convention  on Object
 
 2. For asynchronous API.
 
-     **` (void) handler:(id) arg :(void (^)( id result,BOOL complete))completionHandler）`**
+     **` (void) handler:(id) arg :(JSCallback)completionHandler）`**
+
+     `JSCallback` is a block type:
+
+     ```objective-c
+     typedef void (^JSCallback)(NSString * _Nullable result,BOOL complete); 
+     ```
 
    > Attention: API name can't start with "init", because it is reserved in OC class.
 
@@ -166,6 +174,8 @@ Two points you should keep in mind:
 - Must add "@objc" to Swift API.
 - Must  use "_"  to ignore the first argument name explicitly
 
+The complete example is [here](https://github.com/wendux/DSBridge-IOS/blob/master/dsbridgedemo/JsApiTestSwift.swift) .
+
 ## Namespace
 
 Namespaces can help you better manage your APIs, which is very useful in   hybrid applications, because these applications have a large number of APIs. DSBridge (>= v3.0.0) allows you to classify API with namespace. And the namespace can be multilevel, between different levels with '.' division.
@@ -188,7 +198,7 @@ Normally, when a API is called to end, it returns a result, which corresponds on
 In Object-c 
 
 ```objective-c
-- ( void )callProgress:(NSDictionary *) args :(void (^)(NSNumber * _Nullable result,BOOL complete))completionHandler
+- ( void )callProgress:(NSDictionary *) args :(JSCallback)completionHandler
 {
     value=10;
     hanlder=completionHandler;
@@ -256,7 +266,7 @@ Example:
 {
     return arg;
 }
-- (void) asyn: (id) arg :(void (^)( id _Nullable result,BOOL complete))completionHandler
+- (void) asyn: (id) arg :(JSCallback)completionHandler
 {
     completionHandler(arg,YES);
 }
diff --git a/dsBridge.podspec b/dsBridge.podspec
index cb01294..b309fc4 100644
--- a/dsBridge.podspec
+++ b/dsBridge.podspec
@@ -16,7 +16,7 @@ Pod::Spec.new do |s|
   #
 
   s.name         = "dsBridge"
-  s.version      = "3.0.3"
+  s.version      = "3.0.4"
   s.summary      = "An ios bridge for calling functions synchronously and asynchronously between JavaScript and Object-C in WKWebView/UIWebView"
 
   # This description is used to generate tags and improve search results.
diff --git a/dsbridge.xcodeproj/xcuserdata/du.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist b/dsbridge.xcodeproj/xcuserdata/du.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist
index bf198cb..09cb715 100644
--- a/dsbridge.xcodeproj/xcuserdata/du.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist
+++ b/dsbridge.xcodeproj/xcuserdata/du.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist
@@ -339,5 +339,21 @@
             landmarkType = "7">
          </BreakpointContent>
       </BreakpointProxy>
+      <BreakpointProxy
+         BreakpointExtensionID = "Xcode.Breakpoint.FileBreakpoint">
+         <BreakpointContent
+            shouldBeEnabled = "No"
+            ignoreCount = "0"
+            continueAfterRunningActions = "No"
+            filePath = "dsbridgedemo/JsApiTest.m"
+            timestampString = "558942264.07623"
+            startingColumnNumber = "9223372036854775807"
+            endingColumnNumber = "9223372036854775807"
+            startingLineNumber = "26"
+            endingLineNumber = "26"
+            landmarkName = "-testAsyn::"
+            landmarkType = "7">
+         </BreakpointContent>
+      </BreakpointProxy>
    </Breakpoints>
 </Bucket>
diff --git a/dsbridge/DWKWebView.h b/dsbridge/DWKWebView.h
index 929f5a6..365f526 100644
--- a/dsbridge/DWKWebView.h
+++ b/dsbridge/DWKWebView.h
@@ -8,6 +8,8 @@
 
 #import <WebKit/WebKit.h>
 
+typedef void (^JSCallback)(NSString * _Nullable result,BOOL complete);
+
 @interface DWKWebView : WKWebView <WKUIDelegate>
 
 @property (nullable, nonatomic, weak) id <WKUIDelegate> DSUIDelegate;
diff --git a/dsbridge/dsbridge.h b/dsbridge/dsbridge.h
index 2483075..a710eab 100644
--- a/dsbridge/dsbridge.h
+++ b/dsbridge/dsbridge.h
@@ -9,3 +9,4 @@
 #import <Foundation/Foundation.h>
 #import "JSBUtil.h"
 #import "DWKWebView.h"
+
diff --git a/dsbridgedemo/JsApiTest.h b/dsbridgedemo/JsApiTest.h
index 39440fc..498829a 100644
--- a/dsbridgedemo/JsApiTest.h
+++ b/dsbridgedemo/JsApiTest.h
@@ -7,6 +7,7 @@
 //
 
 #import <Foundation/Foundation.h>
+#import "dsbridge.h"
 
 @interface JsApiTest : NSObject
 
diff --git a/dsbridgedemo/JsApiTest.m b/dsbridgedemo/JsApiTest.m
index a1211cb..d1da4e6 100644
--- a/dsbridgedemo/JsApiTest.m
+++ b/dsbridgedemo/JsApiTest.m
@@ -21,7 +21,7 @@ - (NSString *) testSyn: (NSString *) msg
     return [msg stringByAppendingString:@"[ syn call]"];
 }
 
-- (void) testAsyn:(NSString *) msg :(void (^)(NSString * _Nullable result,BOOL complete))completionHandler
+- (void) testAsyn:(NSString *) msg :(JSCallback) completionHandler
 {
     completionHandler([msg stringByAppendingString:@" [ asyn call]"],YES);
 }
@@ -31,12 +31,12 @@ - (NSString *)testNoArgSyn:(NSDictionary *) args
     return  @"testNoArgSyn called [ syn call]";
 }
 
-- ( void )testNoArgAsyn:(NSDictionary *) args :(void (^)(NSString * _Nullable result,BOOL complete))completionHandler
+- ( void )testNoArgAsyn:(NSDictionary *) args :(JSCallback)completionHandler
 {
     completionHandler(@"testNoArgAsyn called [ asyn call]",YES);
 }
 
-- ( void )callProgress:(NSDictionary *) args :(void (^)(NSNumber * _Nullable result,BOOL complete))completionHandler
+- ( void )callProgress:(NSDictionary *) args :(JSCallback)completionHandler
 {
     value=10;
     hanlder=completionHandler;
@@ -62,7 +62,7 @@ -(void)onTimer:t{
  * redirect requests to native, more about Fly see  https://github.com/wendux/fly
  * @param requestInfo passed by fly.js, more detail reference https://wendux.github.io/dist/#/doc/flyio-en/native
  */
--(void)onAjaxRequest:(NSDictionary *) requestInfo  :(void (^)(NSString * _Nullable result,BOOL complete))completionHandle{
+-(void)onAjaxRequest:(NSDictionary *) requestInfo  :(JSCallback)completionHandler{
    
 }
 
diff --git a/dsbridgedemo/JsApiTestSwift.swift b/dsbridgedemo/JsApiTestSwift.swift
index f3c301e..4d84f73 100644
--- a/dsbridgedemo/JsApiTestSwift.swift
+++ b/dsbridgedemo/JsApiTestSwift.swift
@@ -7,6 +7,7 @@
 //
 
 import Foundation
+typealias JSCallback = (String, Bool)->Void
 
 class JsApiTestSwift: NSObject {
     
@@ -15,7 +16,7 @@ class JsApiTestSwift: NSObject {
         return String(format:"%@[Swift sync call:%@]", arg, "test")
     }
     
-    @objc func testAsyn( _ arg:String, handler: (String, Bool)->Void) {
+    @objc func testAsyn( _ arg:String, handler: JSCallback) {
         handler(String(format:"%@[Swift async call:%@]", arg, "test"), true)
     }
     
diff --git a/dsbridgedemo/JsEchoApi.m b/dsbridgedemo/JsEchoApi.m
index aa61bf0..005e52b 100644
--- a/dsbridgedemo/JsEchoApi.m
+++ b/dsbridgedemo/JsEchoApi.m
@@ -7,6 +7,7 @@
 //
 
 #import "JsEchoApi.h"
+#import "dsbridge.h"
 
 @implementation JsEchoApi
 
@@ -15,7 +16,7 @@ - (id) syn:(id) arg
     return arg;
 }
 
-- (void) asyn: (id) arg :(void (^)( id _Nullable result,BOOL complete))completionHandler
+- (void) asyn: (id) arg :(JSCallback)completionHandler
 {
     completionHandler(arg,YES);
 }
diff --git a/readme-chs.md b/readme-chs.md
index 0ad2655..4a0ca84 100644
--- a/readme-chs.md
+++ b/readme-chs.md
@@ -44,6 +44,8 @@ pod "dsBridge"
 1. 新建一个类，实现API 
 
    ```objective-c
+   #import "dsbridge.h" 
+   ...
    @implementation JsApiTest
    //同步API 
    - (NSString *) testSyn:(NSString *) msg
@@ -51,7 +53,7 @@ pod "dsBridge"
        return [msg stringByAppendingString:@"[ syn call]"];
    }
    //异步API
-   - (void) testAsyn:(NSString *) msg :(void (^)(NSString * _Nullable result,BOOL complete))completionHandler
+   - (void) testAsyn:(NSString *) msg :(JSCallback)completionHandler
    {
        completionHandler([msg stringByAppendingString:@" [ asyn call]"],YES);
    }
@@ -73,9 +75,9 @@ pod "dsBridge"
 
      ```javascript
      //cdn方式引入初始化代码(中国地区慢，建议下载到本地工程)
-     //<script src="https://unpkg.com/dsbridge@3.1.1/dist/dsbridge.js"> </script>
+     //<script src="https://cdn.jsdelivr.net/npm/dsbridge@3.1.4/dist/dsbridge.js"> //</script>
      //npm方式安装初始化代码
-     //npm install dsbridge@3.1.1
+     //npm install dsbridge@3.1.4
      var dsBridge=require("dsbridge")
      ```
 
@@ -120,6 +122,12 @@ pod "dsBridge"
 
    **` (void) handler:(id)arg :(void (^)( id result,BOOL complete))completionHandler）`**
 
+   `JSCallback` 是一个block类型:
+
+   ```objective-c
+   typedef void (^JSCallback)(NSString * _Nullable result,BOOL complete); 
+   ```
+
 > 注意：API名字**不能**以"init"开始，因为oc的类中是被预留的, 如果以"init"开始，执行结果将无法预期(很多时候会crash)。
 >
 
@@ -145,6 +153,8 @@ pod "dsBridge"
 - 必须给Swift API添加 "@objc" 标注。
 - 必须给第一个参数前添加下划线"_"来显式忽略参数名
 
+完整的示例在 [这里](https://github.com/wendux/DSBridge-IOS/blob/master/dsbridgedemo/JsApiTestSwift.swift) .
+
 ## 命名空间
 
 命名空间可以帮助你更好的管理API，这在API数量多的时候非常实用，比如在混合应用中。DSBridge (>= v3.0.0) 支持你通过命名空间将API分类管理，并且命名空间支持多级的，不同级之间只需用'.' 分隔即可。
@@ -169,7 +179,7 @@ pod "dsBridge"
 In Object-c
 
 ```objective-c
-- ( void )callProgress:(NSDictionary *) args :(void (^)(NSNumber * _Nullable result,BOOL complete))completionHandler
+- ( void )callProgress:(NSDictionary *) args :(JSCallback)completionHandler
 {
     value=10;
     hanlder=completionHandler;
@@ -237,7 +247,7 @@ DSBridge已经实现了 Javascript的弹出框函数(alert/confirm/prompt)，这
 {
     return arg;
 }
-- (void) asyn: (id) arg :(void (^)( id _Nullable result,BOOL complete))completionHandler
+- (void) asyn: (id) arg :(JSCallback)completionHandler
 {
     completionHandler(arg,YES);
 }