RecyclerView不会在视图之间切换

Question

I am trying to build a navigation drawer with headers. I've got all working with one exception. First I'll give a brief info about the structure then lay down the exact issue. The structure is as following:

1. I have 2 layout files, one for the drawer headers view called header_row.xml . It contains two widgets, a textview and an imageview. The orientation is vertical, so the viewitem will have the imageview setting under the textview. The the textview in this layout is the header text, and the imageview is a horizontal line that sits under that header text as a simple divider.

2. The second layout is the drawer clickable items. It also contain two widgets, one textview and one imageview. the textview is the clickable item. And the imageview is that item's icon. This layout is horizontal, so the icon sits to the left of the item. This layout is called data_row.xml .

The goal behind these 2 layout files is (try to imagine this) is to have a recycler-view with headers.

My Recycler Adapter code is as follow:

package com.android.yousef.tm;

import android.graphics.drawable.Drawable;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

/**
* Created by Yousef on 3/3/2015.
*/
public class MyRecyclerAdapter extends  
RecyclerView.Adapter<RecyclerView.ViewHolder> {

String[] texts; //An array of the text elements that contains both header 
//text and items text

int[] imgs; // An array of the image elements that contains both headers 
//dividers and items icons.

// NOTE THAT, THE DATA IN THE ABOVE ARRAYS ARE ARRANGE IN ORDER SO THAT 
//POSITIONS 0, 3, AND 5 WILL
// CONTAIN HEADER'S TEXT AND DIVIDER'S IMAGE RESOURCES


private ClickListner clickListner; // Ignore this

//My constructor as bellow getting data from the NavigationDrawer.java class

public MyRecyclerAdapter(String[] texts, int[] imgs) {
    this.texts = texts;
    this.imgs = imgs;
}


// Ignore the listner
public void setClickListner(ClickListner clickListner) {
    this.clickListner = clickListner;
}

@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int  i) {

    // positions 0,3,and 5 are my headers positions
    if(i == 0 || i == 3 || i ==5)
    {
        // if the current position is a header's position then return a  
        //header_row item

        View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.header_row, viewGroup, false);
        return new VHHeader(view);
    }
    else {
        // if the current position is not a header's position then return an  
        //item_row item
        View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.data_row, viewGroup, false);
        return new VHItem(view);
    }
}

@Override
public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int i) {

    // if the current position is a header's position then set header's 
    //value: text and divider

    if(viewHolder instanceof VHHeader)
    {
        ((VHHeader) viewHolder).header.setText(texts[i]);
        ((VHHeader) viewHolder).divider.setImageResource(imgs[i]);
    }

    // if the current position is not a header's position then set item's 
    //value: text and icon

    else if(viewHolder instanceof VHItem)
    {
        ((VHItem) viewHolder).title.setText(texts[i]);
        ((VHItem) viewHolder).icon.setImageResource(imgs[i]);
    }
}

@Override
public int getItemCount() {
    //total rows in my recycler view including header and clickable items.
    return 8;
}

//Ignore the interface
public interface ClickListner {

    public void itemClicked(View v, int position);
}

// My Item's ViewHolder class.
class VHItem extends RecyclerView.ViewHolder {
    TextView title;
    ImageView icon;

    public VHItem(View itemView) {
        super(itemView);
        title = (TextView) itemView.findViewById(R.id.list_txt_data);
        icon = (ImageView) itemView.findViewById(R.id.list_img_data);
    }
}

// My Header's ViewHolder class
class VHHeader extends RecyclerView.ViewHolder {
    TextView header;
    ImageView divider;

    public VHHeader(View itemView) {
        super(itemView);
        header = (TextView) itemView.findViewById(R.id.list_txt_header);
        divider = (ImageView) itemView.findViewById(R.id.list_img_header);
    }
}

}

The problem is that recycler view always takes the first row layout (in my case header_row.xml) and uses it for all the rows regarding their position and thus types as headers (header_row.xml users) or items (data_row.xml users).

Any help please? Thank you.

Answer 1

I found the solution to this. I had to override another method: getViewItemType(); in the adapter in order to check for headers position at getView(); level. So just add the following to the code in the original question:

@Override
public int getItemViewType(int position) {
    if(position == 0 || position == 3 || position ==5)
    {
     HEADER = position;
        return HEADER;
    }
    else {
        ITEM = position;
        return ITEM;
    }
}

Just make sure you declare HEADER AND ITEM.