diff --git a/app/build.gradle b/app/build.gradle
index 28cd0d7..86a38fa 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -5,11 +5,11 @@ apply plugin: 'kotlin-android'
 apply plugin: 'kotlin-android-extensions'
 
 android {
-    compileSdkVersion 30
+    compileSdkVersion 31
     defaultConfig {
         applicationId "com.lxj.demo1"
         minSdkVersion 19
-        targetSdkVersion 28
+        targetSdkVersion 31
         versionCode 1
         versionName "1.0"
     }
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 80bf7b5..b4d3012 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -9,7 +9,8 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
-        <activity android:name="com.lxj.demo1.MainActivity" >
+        <activity android:name="com.lxj.demo1.MainActivity"
+            android:exported="true">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
 
@@ -17,7 +18,8 @@
             </intent-filter>
         </activity>
 
-        <activity android:name="com.lxj.demo1.InFragmentDemo"/>
+        <activity android:name="com.lxj.demo1.InFragmentDemo"
+            android:exported="true"/>
     </application>
 
 </manifest>
\ No newline at end of file
diff --git a/build.gradle b/build.gradle
index d1f0ee3..d8a08b8 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,13 +1,13 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
-    ext.kotlin_version = '1.3.41'
+    ext.kotlin_version = '1.5.0'
     repositories {
         google()
         mavenCentral()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.5.3'
+        classpath 'com.android.tools.build:gradle:4.2.0'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 758de96..f6b961f 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 0ebb310..bff4ad5 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,6 @@
+#Wed Dec 18 19:13:30 CST 2019
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.4-all.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.7.1-all.zip
diff --git a/statelayout-library/build.gradle b/statelayout-library/build.gradle
index a7a2485..5c0223a 100644
--- a/statelayout-library/build.gradle
+++ b/statelayout-library/build.gradle
@@ -2,11 +2,11 @@ apply plugin: 'com.android.library'
 apply plugin: 'kotlin-android'
 
 android {
-    compileSdkVersion 28
+    compileSdkVersion 31
 
     defaultConfig {
         minSdkVersion 19
-        targetSdkVersion 28
+        targetSdkVersion 31
         versionCode 1
         versionName "1.0"
     }
@@ -24,13 +24,3 @@ dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
     implementation 'androidx.appcompat:appcompat:1.3.1'
 }
-
-//publish {
-//    userOrg = 'li-xiaojun'
-//    groupId = 'com.lxj'
-//    artifactId = 'statelayout'
-//    publishVersion = '1.2.2'
-//    repoName = 'jrepo'
-//    desc = 'Simple way to change your layout state, like loading, _statelayout_empty, _statelayout_error. Strong customizitaion, written by Kotlin!'
-//    website = 'https://github.com/li-xiaojun/StateLayout'
-//}
\ No newline at end of file
diff --git a/statelayout-library/src/main/java/com/lxj/statelayout/StateLayout.kt b/statelayout-library/src/main/java/com/lxj/statelayout/StateLayout.kt
index 5c4f7d5..ba9fc8c 100644
--- a/statelayout-library/src/main/java/com/lxj/statelayout/StateLayout.kt
+++ b/statelayout-library/src/main/java/com/lxj/statelayout/StateLayout.kt
@@ -171,10 +171,10 @@ class StateLayout @JvmOverloads constructor(context: Context, attributeSet: Attr
 
     private fun switch(v: View?) {
         if (switchTask != null) {
-            mHandler.removeCallbacks(switchTask)
+            mHandler.removeCallbacks(switchTask!!)
         }
         switchTask = SwitchTask(v)
-        mHandler.post(switchTask)
+        mHandler.post(switchTask!!)
     }
 
     private fun retry() {
diff --git a/statelayout-library/src/main/res/layout/_loading_layout_empty.xml b/statelayout-library/src/main/res/layout/_loading_layout_empty.xml
index f0214dd..b1aa33d 100644
--- a/statelayout-library/src/main/res/layout/_loading_layout_empty.xml
+++ b/statelayout-library/src/main/res/layout/_loading_layout_empty.xml
@@ -3,15 +3,14 @@
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:paddingBottom="30dp"
     android:gravity="center"
     android:orientation="vertical">
 
     <ImageView
         android:id="@+id/ivNoDataIcon"
         android:src="@drawable/_statelayout_empty"
-        android:layout_width="64dp"
-        android:layout_height="64dp"
+        android:layout_width="60dp"
+        android:layout_height="60dp"
         android:layout_gravity="center"/>
 
     <TextView
@@ -20,7 +19,7 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_gravity="center"
-        android:textColor="#444"
-        android:textSize="15sp"
-        android:text="@string/nodata"/>
+        android:textColor="@color/_statelayout_hint_color"
+        android:textSize="14sp"
+        android:text="@string/_statelayout_nodata"/>
 </LinearLayout>
\ No newline at end of file
diff --git a/statelayout-library/src/main/res/layout/_loading_layout_error.xml b/statelayout-library/src/main/res/layout/_loading_layout_error.xml
index 19f2369..f245a6b 100644
--- a/statelayout-library/src/main/res/layout/_loading_layout_error.xml
+++ b/statelayout-library/src/main/res/layout/_loading_layout_error.xml
@@ -18,9 +18,9 @@
         android:layout_gravity="center"
         android:paddingLeft="14dp"
         android:paddingRight="14dp"
-        android:textSize="12sp"
+        android:textSize="14sp"
         android:layout_marginTop="15dp"
-        android:text="@string/load_failed_try_again"
-        android:textColor="#444"/>
+        android:text="@string/_statelayout_load_failed"
+        android:textColor="@color/_statelayout_hint_color"/>
 
 </LinearLayout>
\ No newline at end of file
diff --git a/statelayout-library/src/main/res/values-en/strings.xml b/statelayout-library/src/main/res/values-en/strings.xml
index b025638..951c5a2 100644
--- a/statelayout-library/src/main/res/values-en/strings.xml
+++ b/statelayout-library/src/main/res/values-en/strings.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <string name="load_failed_try_again">Load failed, try again</string>
-    <string name="nodata">No Data</string>
+    <string name="_statelayout_load_failed">Click to retry</string>
+    <string name="_statelayout_nodata">No Data</string>
 </resources>
\ No newline at end of file
diff --git a/statelayout-library/src/main/res/values/colors.xml b/statelayout-library/src/main/res/values/colors.xml
new file mode 100644
index 0000000..e56f2de
--- /dev/null
+++ b/statelayout-library/src/main/res/values/colors.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <color name="_statelayout_hint_color">#656565</color>
+</resources>
\ No newline at end of file
diff --git a/statelayout-library/src/main/res/values/strings.xml b/statelayout-library/src/main/res/values/strings.xml
index 40703b3..deb3c16 100644
--- a/statelayout-library/src/main/res/values/strings.xml
+++ b/statelayout-library/src/main/res/values/strings.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <string name="load_failed_try_again">加载失败，点击重试</string>
-    <string name="nodata">暂无数据</string>
+    <string name="_statelayout_load_failed">点击重试</string>
+    <string name="_statelayout_nodata">暂无数据</string>
 </resources>
\ No newline at end of file