条形码片段“在空对象引用上调用虚拟方法'void android.widget.Button.setOnClickListener（android.view.View $ OnClickListener）'”

I'm trying to use the ZXing library for make a Bar Code scan in a Fragment. I have successful imported the library but when I choose from the APP this Fragment the APP crash with the following traceback:I'm trying to use the ZXing library for make a