diff --git a/README.md b/README.md
index 9d0df76..cc86e78 100755
--- a/README.md
+++ b/README.md
@@ -28,7 +28,7 @@ Android APK 版本更新的下载和安装,适配7.0，8.0下载安装
 #### 2.在Module目录下的build.gradle中添加依赖
 ``` gradle
 	dependencies {
-	     compile 'com.github.maning0303:MNUpdateAPK:V2.0.0'
+	     compile 'com.github.maning0303:MNUpdateAPK:V2.0.1'
 	}
 ```
 
@@ -54,7 +54,7 @@ Android APK 版本更新的下载和安装,适配7.0，8.0下载安装
       //下载APK
       InstallUtils.with(this)
               //必须-下载地址
-              .setApkUrl(Constants.APK_URL_03)
+              .setApkUrl(Constants.APK_URL_01)
               //非必须-下载保存的文件的完整路径+/name.apk，使用自定义路径需要获取读写权限
               .setApkPath(Constants.APK_SAVE_PATH)
               //非必须-下载回调
@@ -111,6 +111,8 @@ Android APK 版本更新的下载和安装,适配7.0，8.0下载安装
       //取消下载
       InstallUtils.cancleDownload();
       
+      //是否正在下载
+      InstallUtils.isDownloading();
       
       //单独设置下载监听
       InstallUtils.setDownloadCallBack(new InstallUtils.DownloadCallBack() {
@@ -206,6 +208,11 @@ Android APK 版本更新的下载和安装,适配7.0，8.0下载安装
 ##### 请添加okhttp3混淆
 
 ## 版本记录:
+##### 版本 V2.0.1:
+    1.优化代码，防止部分手机出现异常情况
+    2.添加新的方法：isDownloading --- 判断是不是正在下载
+    3.优化onLoading回调频率，只有转progress+1才回调一次，防止在当前方法更新notify出现卡顿现象
+    
 ##### 版本 V2.0.0:
     1.升级下载，使用okhttp下载
     2.优化安装代码，使用startActivityForResult()
diff --git a/app/src/main/java/com/maning/mnupdateapk/MainActivity.java b/app/src/main/java/com/maning/mnupdateapk/MainActivity.java
index a02b590..82de128 100755
--- a/app/src/main/java/com/maning/mnupdateapk/MainActivity.java
+++ b/app/src/main/java/com/maning/mnupdateapk/MainActivity.java
@@ -58,8 +58,10 @@ private void initViews() {
     @Override
     protected void onResume() {
         super.onResume();
-        //设置监听
-        InstallUtils.setDownloadCallBack(downloadCallBack);
+        //设置监听,防止其他页面设置回调后当前页面回调失效
+        if (InstallUtils.isDownloading()) {
+            InstallUtils.setDownloadCallBack(downloadCallBack);
+        }
     }
 
     private void initCallBack() {
@@ -97,8 +99,11 @@ public void onFail(Exception e) {
 
             @Override
             public void onLoading(long total, long current) {
+                //内部做了处理，onLoading 进度转回progress肯定是+1，防止频率过快
                 Log.i(TAG, "InstallUtils----onLoading:-----total:" + total + ",current:" + current);
-                tv_progress.setText((int) (current * 100 / total) + "%");
+                int progress = (int) (current * 100 / total);
+                //进度要处理一下
+                tv_progress.setText(progress + "%");
             }
 
             @Override
diff --git a/library_update/src/main/java/com/maning/updatelibrary/InstallUtils.java b/library_update/src/main/java/com/maning/updatelibrary/InstallUtils.java
index 0868d95..e3314d8 100755
--- a/library_update/src/main/java/com/maning/updatelibrary/InstallUtils.java
+++ b/library_update/src/main/java/com/maning/updatelibrary/InstallUtils.java
@@ -30,6 +30,10 @@ public class InstallUtils {
     private String httpUrl;
     private String filePath;
     private static DownloadCallBack mDownloadCallBack;
+    /**
+     * 是不是在正在下载
+     */
+    private static boolean isDownloading = false;
 
     /**
      * 下载回调监听
@@ -52,13 +56,23 @@ public interface DownloadCallBack {
     private InstallUtils() {
     }
 
+    /**
+     * 是否正在下载
+     */
+    public static boolean isDownloading() {
+        return isDownloading;
+    }
+
     /**
      * 设置监听
      *
      * @param downloadCallBack
      */
     public static void setDownloadCallBack(DownloadCallBack downloadCallBack) {
-        mDownloadCallBack = downloadCallBack;
+        //判断有没有开始
+        if (isDownloading) {
+            mDownloadCallBack = downloadCallBack;
+        }
     }
 
 
@@ -113,6 +127,10 @@ public InstallUtils setCallBack(DownloadCallBack downloadCallBack) {
      * 开始下载
      */
     public void startDownload() {
+        //先取消之前的下载
+        if(isDownloading){
+            cancleDownload();
+        }
         //判断下载保存路径是不是空
         if (TextUtils.isEmpty(filePath)) {
             filePath = MNUtils.getCachePath(mContext) + "/update.apk";
@@ -122,8 +140,11 @@ public void startDownload() {
                 .url(httpUrl)
                 .tag(InstallUtils.class)
                 .execute(new AbsFileProgressCallback() {
+                    int currentProgress = 0;
+
                     @Override
                     public void onSuccess(String result) {
+                        isDownloading = false;
                         if (mDownloadCallBack != null) {
                             mDownloadCallBack.onComplete(filePath);
                         }
@@ -131,13 +152,21 @@ public void onSuccess(String result) {
 
                     @Override
                     public void onProgress(long bytesRead, long contentLength, boolean done) {
+                        isDownloading = true;
                         if (mDownloadCallBack != null) {
-                            mDownloadCallBack.onLoading(contentLength, bytesRead);
+                            //计算进度
+                            int progress = (int) (bytesRead * 100 / contentLength);
+                            //只有进度+1才回调，防止过快
+                            if (progress - currentProgress >= 1) {
+                                mDownloadCallBack.onLoading(contentLength, bytesRead);
+                            }
+                            currentProgress = progress;
                         }
                     }
 
                     @Override
                     public void onFailed(String errorMsg) {
+                        isDownloading = false;
                         if (mDownloadCallBack != null) {
                             mDownloadCallBack.onFail(new Exception(errorMsg));
                         }
@@ -145,6 +174,7 @@ public void onFailed(String errorMsg) {
 
                     @Override
                     public void onStart() {
+                        isDownloading = true;
                         if (mDownloadCallBack != null) {
                             mDownloadCallBack.onStart();
                         }
@@ -152,6 +182,7 @@ public void onStart() {
 
                     @Override
                     public void onCancle() {
+                        isDownloading = false;
                         if (mDownloadCallBack != null) {
                             mDownloadCallBack.cancle();
                         }