diff --git a/module_camera/src/main/api21/com/google/android/cameraview/Camera2.java b/module_camera/src/main/api21/com/google/android/cameraview/Camera2.java
index d21632f..7bbbb9f 100644
--- a/module_camera/src/main/api21/com/google/android/cameraview/Camera2.java
+++ b/module_camera/src/main/api21/com/google/android/cameraview/Camera2.java
@@ -356,7 +356,8 @@ void takePicture() {
     @Override
     void setDisplayOrientation(int displayOrientation) {
         mDisplayOrientation = displayOrientation;
-        mPreview.setDisplayOrientation(mDisplayOrientation);
+        if (mPreview != null)
+            mPreview.setDisplayOrientation(mDisplayOrientation);
     }
 
     @Override
diff --git a/module_camera/src/main/java/com/ailiwean/core/view/NBZxingView.kt b/module_camera/src/main/java/com/ailiwean/core/view/NBZxingView.kt
index 8385ede..71ff60d 100644
--- a/module_camera/src/main/java/com/ailiwean/core/view/NBZxingView.kt
+++ b/module_camera/src/main/java/com/ailiwean/core/view/NBZxingView.kt
@@ -102,7 +102,8 @@ abstract class NBZxingView @JvmOverloads constructor(context: Context, attribute
 
     override fun onPause() {
         super.onPause()
-        scan_bar.stopAnim()
+        if (scan_bar != null)
+            scan_bar.stopAnim()
     }
 
     override fun onDestroy() {
diff --git a/module_camera/src/main/java/com/google/android/cameraview/CameraView.java b/module_camera/src/main/java/com/google/android/cameraview/CameraView.java
index fb65638..7af7915 100644
--- a/module_camera/src/main/java/com/google/android/cameraview/CameraView.java
+++ b/module_camera/src/main/java/com/google/android/cameraview/CameraView.java
@@ -129,7 +129,6 @@ public CameraView(Context context, AttributeSet attrs, int defStyleAttr) {
         } else {
             mImpl = new Camera2Api23(mCallbacks, context);
         }
-
 //        mImpl = new Camera1(mCallbacks, preview);
         // Attributes
         TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CameraView, defStyleAttr,
@@ -219,6 +218,8 @@ protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
 //            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
 //        }
         super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+        if (mImpl.getView() == null)
+            return;
         // Measure the TextureView
         int width = getMeasuredWidth();
         int height = getMeasuredHeight();