现象：预览有，真机运行没有

跟清单文件activity主题设置有关，去掉 android:theme="@style/Theme.Design.NoActionBar" 就有了

 <activity
            android:name=".activity.ModifyNumActivity"
            android:exported="false"
            android:theme="@style/Theme.Design.NoActionBar" />

但是还有个问题，就是不能全屏了，再把继承的Activity换一下，增加全屏代码控制就好了

public class ProfessionInfoActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager
                .LayoutParams.FLAG_FULLSCREEN);
        this.requestWindowFeature(Window.FEATURE_NO_TITLE);

        setContentView(R.layout.activity_profession_info);
    }
}