Question

我正在尝试制作注册页面，用户将在每个页面中输入他们喜欢的内容（activity_register_screen1和activity_register_screen2）。我试图使用EditText声明findViewById。与OnCreate中的RegisterActivity.java方法一样，当我在最后一页点击完成时，startRegister()开始。运行startRegister时，应该存储在先前页面中输入的数据，然后使用showAlertDialog方法显示文本值。有谁知道怎么做？

这是RegisterActivity.java

public class RegisterActivity extends AppCompatActivity
{
    /*UI*/
    private ViewPager mViewPager;
    private RegisterManager mRegisterManager;
    private int[] mLayouts;
    private TextView[] dots;
    private LinearLayout dotsLayout;
    private Button next;
    private ViewPagerAdapter viewPagerAdapter;
    private EditText mText;

    /*Firebase*/
    private DatabaseReference mDatabaseUser;

    /*Other*/
    public String text;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);

        /*UI*/

        /*Firebase*/
        mDatabaseUser = FirebaseDatabase.getInstance().getReference().child("User");

        /*Other*/
        mRegisterManager = new RegisterManager(this);

        if(!mRegisterManager.check())
        {
            mRegisterManager.setFirst(false);
            Intent i = new Intent(RegisterActivity.this, GetStartedActivity.class);
            startActivity(i);
            finish();
        }

        setContentView(R.layout.activity_register);

        mViewPager = (ViewPager)findViewById(R.id.activity_register_view_pager);
        dotsLayout = (LinearLayout)findViewById(R.id.activity_register_layout_dot);
        next = (Button)findViewById(R.id.activity_register_btn_next);
        mLayouts = new int[]
                {
                        R.layout.activity_register_screen1,
                        R.layout.activity_register_screen2,
                        R.layout.activity_register_screen3,
                        R.layout.activity_register_screen4,
                        R.layout.activity_register_screen5
                };

        addBottomDots(0);
        viewPagerAdapter = new ViewPagerAdapter();
        mViewPager.setAdapter(viewPagerAdapter);
        mViewPager.addOnPageChangeListener(viewListener);

        next.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
                int current = getItem(+1);

                if(current < mLayouts.length)
                {
                    mViewPager.setCurrentItem(current);
                }
                else
                {
                    startRegister();
                }
            }
        });
    }

    private void showAlertDialog(String title, String message)
    {
        AlertDialog alertDialog = new AlertDialog.Builder(RegisterActivity.this).create();
        alertDialog.setTitle(title);
        alertDialog.setMessage(message);
        alertDialog.setButton(AlertDialog.BUTTON_NEGATIVE, "OK", new DialogInterface.OnClickListener()
        {
            public void onClick(DialogInterface dialog, int which)
            {
                dialog.dismiss();
            }
        });
        alertDialog.show();
    }

    private void startRegister()
    {
        text = mText.getText().toString();
        showAlertDialog("text", text);
    }

    private void addBottomDots(int position)
    {
        dots = new TextView[mLayouts.length];
        int[] colorActive = getResources().getIntArray(R.array.dot_active);
        int[] colorInactive = getResources().getIntArray(R.array.dot_inactive);
        dotsLayout.removeAllViews();
        for(int i = 0; i < dots.length; i++)
        {
            dots[i] = new TextView(this);
            dots[i].setText(Html.fromHtml("&#8226;"));
            dots[i].setTextSize(35);
            dots[i].setTextColor(colorInactive[position]);
            dotsLayout.addView(dots[i]);
        }
        if(dots.length > 0)
        {
            dots[position].setTextColor(colorActive[position]);
        }
    }

    private int getItem(int i)
    {
        return mViewPager.getCurrentItem() + i;
    }

    ViewPager.OnPageChangeListener viewListener = new ViewPager.OnPageChangeListener()
    {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels)
        {

        }

        @Override
        public void onPageSelected(int position)
        {
            addBottomDots(position);
            if(position == mLayouts.length - 1)
            {
                next.setText("FINISH");
            }
            else
            {
                next.setText("NEXT");
            }
        }

        @Override
        public void onPageScrollStateChanged(int state)
        {

        }
    };

    public class ViewPagerAdapter extends PagerAdapter
    {
        private LayoutInflater mLayoutInflater;

        @Override
        public Object instantiateItem(ViewGroup container, int position)
        {
            mLayoutInflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            View v = mLayoutInflater.inflate(mLayouts[position], container, false);

            mText = (EditText)v.findViewById(R.id.activity_register_screen1_text);

            container.addView(v);

            return v;
        }

        @Override
        public void setPrimaryItem(ViewGroup container, int position, Object object)
        {
            super.setPrimaryItem(container, position, object);
        }

        @Override
        public int getCount()
        {
            return mLayouts.length;
        }

        @Override
        public boolean isViewFromObject(View view, Object object)
        {
            return view == object;
        }

        @Override
        public void destroyItem(ViewGroup container, int position, Object object)
        {
            View v = (View)object;
            container.removeView(v);
        }
    }
}

这是RegisterManager.java

public class RegisterManager
{
    SharedPreferences pref;
    SharedPreferences.Editor editor;
    Context context;

    public RegisterManager(Context context)
    {
        this.context = context;
        pref = context.getSharedPreferences("first", 0);
        editor = pref.edit();
    }

    public void setFirst(boolean isFirst)
    {
        editor.putBoolean("check", isFirst);
        editor.commit();
    }

    public boolean check()
    {
        return pref.getBoolean("check", true);
    }
}

这是activity_register_screen1.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/register_screen1">

    <LinearLayout
        android:id="@+id/activity_register_screen1_linear_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:layout_centerHorizontal="true"
        android:orientation="vertical">

        <ImageView
            android:layout_width="120dp"
            android:layout_height="120dp"
            android:src="@drawable/ic_live_help_white_24dp"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Sports"
            android:textColor="#ffffff"
            android:textSize="40dp"
            android:textStyle="bold"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="20dp"
            android:paddingLeft="30dp"
            android:paddingRight="30dp"
            android:text="The Easiest Way to Follow Your Favorite Sports!"
            android:textAlignment="center"
            android:textColor="#ffffff"
            android:textSize="24dp"/>
    </LinearLayout>

    <EditText
        android:id="@+id/activity_register_screen1_text"
        android:layout_below="@+id/activity_register_screen1_linear_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="30dp"
        android:layout_marginLeft="16dp"
        android:layout_marginRight="16dp"
        android:hint="input!!"
        android:textSize="20dp"
        android:background="@drawable/input_outline"/>

</RelativeLayout>

这是activity_register_screen2.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/register_screen2">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:layout_centerHorizontal="true"
        android:orientation="vertical">

        <ImageView
            android:layout_width="120dp"
            android:layout_height="120dp"
            android:src="@drawable/ic_live_help_white_24dp"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Sports"
            android:textColor="#ffffff"
            android:textSize="40dp"
            android:textStyle="bold"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="20dp"
            android:paddingLeft="30dp"
            android:paddingRight="30dp"
            android:text="The Easiest Way to Follow Your Favorite Sports!"
            android:textAlignment="center"
            android:textColor="#ffffff"
            android:textSize="24dp"/>
    </LinearLayout>

</RelativeLayout>

Answer 1

试试这个

if(mText ==null) {
   mText = (EditText)v.findViewById(R.id.activity_register_screen1_text);

}

你的问题是＆＃34;（EditText）v.findViewById（R.id.activity_register_screen1_text）== null＆＃34;。因为activity_register_screen2.xml没有R.id.activity_register_screen1_text。

Android ViewPagerAdapter EditText始终返回null

1 个答案: