diff --git a/app/src/main/java/com/highcapable/yukihookapi/demo/MainActivity.kt b/app/src/main/java/com/highcapable/yukihookapi/demo/MainActivity.kt
index 47883946..e25eb587 100644
--- a/app/src/main/java/com/highcapable/yukihookapi/demo/MainActivity.kt
+++ b/app/src/main/java/com/highcapable/yukihookapi/demo/MainActivity.kt
@@ -36,13 +36,15 @@ import com.highcapable.yukihookapi.hook.xposed.YukiHookModuleStatus
 
 class MainActivity : AppCompatActivity() {
 
+    private var a = "没更改的变量"
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
         // for test
         AlertDialog.Builder(this)
             .setTitle("Hook 方法返回值测试")
-            .setMessage(test() + "\n模块是否已激活：${YukiHookModuleStatus.isActive()}")
+            .setMessage(test() + "\n变量：$a\n模块是否已激活：${YukiHookModuleStatus.isActive()}")
             .setPositiveButton("下一个") { _, _ ->
                 AlertDialog.Builder(this)
                     .setTitle("Hook 方法参数测试")
diff --git a/app/src/main/java/com/highcapable/yukihookapi/demo/hook/MainHooker.kt b/app/src/main/java/com/highcapable/yukihookapi/demo/hook/MainHooker.kt
index 0e32f27f..2f151f6c 100644
--- a/app/src/main/java/com/highcapable/yukihookapi/demo/hook/MainHooker.kt
+++ b/app/src/main/java/com/highcapable/yukihookapi/demo/hook/MainHooker.kt
@@ -33,6 +33,7 @@ import com.highcapable.yukihookapi.demo.BuildConfig
 import com.highcapable.yukihookapi.demo.InjectTest
 import com.highcapable.yukihookapi.demo.MainActivity
 import com.highcapable.yukihookapi.hook.entity.YukiBaseHooker
+import com.highcapable.yukihookapi.hook.type.BundleClass
 import com.highcapable.yukihookapi.hook.type.StringType
 
 class MainHooker : YukiBaseHooker() {
@@ -40,6 +41,18 @@ class MainHooker : YukiBaseHooker() {
     override fun onHook() =
         loadApp(name = BuildConfig.APPLICATION_ID) {
             MainActivity::class.java.hook {
+                injectMember {
+                    method {
+                        name = "onCreate"
+                        param(BundleClass)
+                        beforeHook {
+                            field {
+                                name = "a"
+                                type = StringType
+                            }.set(instance, "这段文字被修改成功了")
+                        }
+                    }
+                }
                 injectMember {
                     method {
                         name = "test"
diff --git a/app/src/main/java/com/highcapable/yukihookapi/demo/hook/inject/MainInjecter.kt b/app/src/main/java/com/highcapable/yukihookapi/demo/hook/inject/MainInjecter.kt
index 7fe0899c..bf38317f 100644
--- a/app/src/main/java/com/highcapable/yukihookapi/demo/hook/inject/MainInjecter.kt
+++ b/app/src/main/java/com/highcapable/yukihookapi/demo/hook/inject/MainInjecter.kt
@@ -53,6 +53,18 @@ class MainInjecter : YukiHookXposedInitProxy {
         encase(BuildConfig.APPLICATION_ID) {
             loadApp(name = BuildConfig.APPLICATION_ID) {
                 MainActivity::class.java.hook {
+                    injectMember {
+                        method {
+                            name = "onCreate"
+                            param(BundleClass)
+                            beforeHook {
+                                field {
+                                    name = "a"
+                                    type = StringType
+                                }.set(instance, "这段文字被修改成功了")
+                            }
+                        }
+                    }
                     injectMember {
                         method {
                             name = "test"
diff --git a/yukihookapi/src/main/java/com/highcapable/yukihookapi/hook/core/YukiHookCreater.kt b/yukihookapi/src/main/java/com/highcapable/yukihookapi/hook/core/YukiHookCreater.kt
index e7d71b95..560df87a 100644
--- a/yukihookapi/src/main/java/com/highcapable/yukihookapi/hook/core/YukiHookCreater.kt
+++ b/yukihookapi/src/main/java/com/highcapable/yukihookapi/hook/core/YukiHookCreater.kt
@@ -153,7 +153,7 @@ class YukiHookCreater(private val packageParam: PackageParam, val hookClass: Cla
          * @param initiate 方法体
          * @return [FieldFinder.Result]
          */
-        fun field(initiate: FieldFinder.() -> Unit) =
+        fun HookParam.field(initiate: FieldFinder.() -> Unit) =
             try {
                 FieldFinder().apply(initiate).find()
             } catch (e: Throwable) {
@@ -161,7 +161,7 @@ class YukiHookCreater(private val packageParam: PackageParam, val hookClass: Cla
                 onNoSuchMemberCallback?.invoke(e)
                 onFailureCallback?.invoke(e)
                 if (onNoSuchMemberCallback == null && onFailureCallback == null) onHookFailureMsg(e)
-                null
+                FieldFinder().Result()
             }
 
         /**
@@ -372,6 +372,13 @@ class YukiHookCreater(private val packageParam: PackageParam, val hookClass: Cla
              */
             inner class Result {
 
+                /**
+                 * 设置变量实例
+                 * @param instance 变量所在的实例对象 - 如果是静态可不填 - 默认 null
+                 * @param any 设置的实例内容
+                 */
+                fun set(instance: Any? = null, any: Any?) = fieldInstance?.set(instance, any)
+
                 /**
                  * 得到变量实例
                  * @param instance 变量所在的实例对象 - 如果是静态可不填 - 默认 null