diff --git a/app/build.gradle b/app/build.gradle
index fb78768..9740c85 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -6,19 +6,31 @@ android {
     defaultConfig {
         applicationId "net.ossrs.yasea.demo"
         minSdkVersion 18
-        targetSdkVersion 22
+        targetSdkVersion 26
         versionCode 1
         versionName "2.6"
         ndk {
             abiFilters "armeabi-v7a", "arm64-v8a", "x86", "mips"
         }
     }
+    // 签名配置
+    signingConfigs {
+        config {
+            keyAlias 'key0'
+            keyPassword '123456'
+            storeFile file('../keystore.jks')
+            storePassword '123456'
+        }
+    }
+
     buildTypes {
         release {
             minifyEnabled false
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+            signingConfig signingConfigs.config
         }
     }
+
 }
 
 dependencies {
diff --git a/app/src/main/java/net/ossrs/yasea/demo/MainActivity.java b/app/src/main/java/net/ossrs/yasea/demo/MainActivity.java
index 82b7227..7b8ae72 100644
--- a/app/src/main/java/net/ossrs/yasea/demo/MainActivity.java
+++ b/app/src/main/java/net/ossrs/yasea/demo/MainActivity.java
@@ -1,11 +1,16 @@
 package net.ossrs.yasea.demo;
 
+import android.Manifest;
 import android.content.SharedPreferences;
 import android.content.pm.ActivityInfo;
+import android.content.pm.PackageManager;
 import android.content.res.Configuration;
 import android.hardware.Camera;
+import android.os.Build;
 import android.os.Bundle;
 import android.os.Environment;
+import android.support.v4.app.ActivityCompat;
+import android.support.v4.content.ContextCompat;
 import android.support.v7.app.AppCompatActivity;
 import android.util.Log;
 import android.view.Menu;
@@ -32,6 +37,7 @@ public class MainActivity extends AppCompatActivity implements RtmpHandler.RtmpL
                         SrsRecordHandler.SrsRecordListener, SrsEncodeHandler.SrsEncodeListener {
 
     private static final String TAG = "Yasea";
+    public final static int RC_CAMERA = 100;
 
     private Button btnPublish;
     private Button btnSwitchCamera;
@@ -48,6 +54,7 @@ public class MainActivity extends AppCompatActivity implements RtmpHandler.RtmpL
 
     private int mWidth = 640;
     private int mHeight = 480;
+    private boolean isPermissionGranted = false;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -59,6 +66,41 @@ public class MainActivity extends AppCompatActivity implements RtmpHandler.RtmpL
         // response screen rotation event
         setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_FULL_SENSOR);
 
+        requestPermission();
+    }
+
+    private void requestPermission() {
+        //1. 检查是否已经有该权限
+        if (Build.VERSION.SDK_INT >= 23 && (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)
+                != PackageManager.PERMISSION_GRANTED || ContextCompat.checkSelfPermission(this, Manifest.permission.RECORD_AUDIO)
+                != PackageManager.PERMISSION_GRANTED)) {
+            //2. 权限没有开启，请求权限
+            ActivityCompat.requestPermissions(this,
+                    new String[]{Manifest.permission.CAMERA, Manifest.permission.RECORD_AUDIO}, RC_CAMERA);
+        }else{
+            //权限已经开启，做相应事情
+            isPermissionGranted = true;
+            init();
+        }
+    }
+
+    //3. 接收申请成功或者失败回调
+    @Override
+    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
+        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
+        if (requestCode == RC_CAMERA) {
+            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
+                //权限被用户同意,做相应的事情
+                isPermissionGranted = true;
+                init();
+            } else {
+                //权限被用户拒绝，做相应的事情
+                finish();
+            }
+        }
+    }
+
+    private void init() {
         // restore data.
         sp = getSharedPreferences("Yasea", MODE_PRIVATE);
         rtmpUrl = sp.getString("rtmpUrl", rtmpUrl);
@@ -74,7 +116,7 @@ public class MainActivity extends AppCompatActivity implements RtmpHandler.RtmpL
         btnPause = (Button) findViewById(R.id.pause);
         btnPause.setEnabled(false);
         mCameraView = (SrsCameraView) findViewById(R.id.glsurfaceview_camera);
-      
+
         mPublisher = new SrsPublisher(mCameraView);
         mPublisher.setEncodeHandler(new SrsEncodeHandler(this));
         mPublisher.setRtmpHandler(new RtmpHandler(this));
@@ -83,15 +125,15 @@ public class MainActivity extends AppCompatActivity implements RtmpHandler.RtmpL
         mPublisher.setOutputResolution(mHeight, mWidth); // 这里要和preview反过来
         mPublisher.setVideoHDMode();
         mPublisher.startCamera();
-      
+
         mCameraView.setCameraCallbacksHandler(new SrsCameraView.CameraCallbacksHandler(){
             @Override
             public void onCameraParameters(Camera.Parameters params) {
-                //params.setFocusMode("custom-focus");                
+                //params.setFocusMode("custom-focus");
                 //params.setWhiteBalance("custom-balance");
                 //etc...
             }
-        });      
+        });
 
         btnPublish.setOnClickListener(new View.OnClickListener() {
             @Override
@@ -249,12 +291,12 @@ public class MainActivity extends AppCompatActivity implements RtmpHandler.RtmpL
     @Override
     protected void onStart() {
         super.onStart();
-        if(mPublisher.getCamera() == null){
+        if(mPublisher.getCamera() == null && isPermissionGranted){
             //if the camera was busy and available again
             mPublisher.startCamera();
         }
-    }                           
-                          
+    }
+
     @Override
     protected void onResume() {
         super.onResume();
@@ -447,4 +489,5 @@ public class MainActivity extends AppCompatActivity implements RtmpHandler.RtmpL
     public void onEncodeIllegalArgumentException(IllegalArgumentException e) {
         handleException(e);
     }
+
 }
diff --git a/keystore.jks b/keystore.jks
new file mode 100644
index 0000000..d124a00
Binary files /dev/null and b/keystore.jks differ
diff --git a/library/build.gradle b/library/build.gradle
index 401e6f5..cb9740d 100644
--- a/library/build.gradle
+++ b/library/build.gradle
@@ -5,7 +5,7 @@ android {
 
     defaultConfig {
         minSdkVersion 18
-        targetSdkVersion 22
+        targetSdkVersion 26
         versionCode 1
         versionName "2.6"