使用java代码将textview与父级对齐

Question

适配器

public class MessageAdapter extends RecyclerView.Adapter<MessageAdapter.MessageViewHolder>{
private List<Messages> mMessagesList;
private FirebaseAuth mAuth;

public class MessageViewHolder extends RecyclerView.ViewHolder{
    public TextView messageText;
    public MessageViewHolder(View view)
    {
        super(view);
        messageText = (TextView)view.findViewById(R.id.message_text_layout);
    }
}

public MessageAdapter (List<Messages>mMessagesList)

{
    this.mMessagesList = mMessagesList;
}

@Override
public MessageViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
{
    View V = LayoutInflater.from(parent.getContext()).inflate(R.layout.activity_chat_custom,parent,false);
    mAuth = FirebaseAuth.getInstance();
    return new MessageViewHolder(V);
}

@Override
public void onBindViewHolder(MessageViewHolder holder, int position) {

        String current_user_id = mAuth.getInstance().getCurrentUser().getUid();
        Messages messages = mMessagesList.get(position);
        String from_user = messages.getFrom();

    if (from_user!=null && from_user.equals(current_user_id)){
            holder.messageText.setBackgroundResource(R.drawable.text_background1);
            holder.messageText.setTextColor(Color.BLACK);

        RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) holder.messageText.getLayoutParams();
        params.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
        holder.messageText.setLayoutParams(params);

    }else {
            holder.messageText.setBackgroundResource(R.drawable.text_background2);
            holder.messageText.setTextColor(Color.BLACK);

        RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) holder.messageText.getLayoutParams();
        params.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
        holder.messageText.setLayoutParams(params);
        }

        holder.messageText.setText(messages.getMessage());
    }

@Override
public  int getItemCount() {
    return mMessagesList.size();
}


public void setMessagesList(List<Messages> mMessagesList) {
    this.mMessagesList = mMessagesList;
}

}

自定义布局

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/message_single_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="12dp">

<TextView
    android:id="@+id/message_text_layout"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentStart="true"
    android:layout_alignParentTop="true"
    android:background="@drawable/messages_text_background"
    android:padding="10dp"
    android:text="Textview"
    android:textSize="20dp"
    android:textColor="@color/black"/>

</RelativeLayout>

请帮帮我...我尝试使用参数...但它仍然没有给我结果...我从来没有处理过这个问题，因为总是在 xml 中对齐它但现在我不能这样做是因为它必须根据条件对齐所以请帮助我......提前谢谢......

Answer 1

你有两种可能的方法

第一

删除

android:layout_alignParentStart="true"

来自您的 TextView

第二 在你的 onBindViewHolder 添加一个像这样的“removeRule”

params.removeRule(RelativeLayout.ALIGN_PARENT_START);

在添加新规则之前。

这是我测试过的代码：

第一

        @Override
        protected void onBindViewHolder(IngredienteViewHolder holder, int position, Ingrediente model) {
            holder.name.setText(model.getName());
            holder.setIngrediente(model);
            if (position % 2 == 0){
                holder.name.setBackgroundColor(Color.BLACK);
                RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams)holder.name.getLayoutParams();
                params.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
                holder.name.setLayoutParams(params); //causes layout update
            } else {
                holder.name.setBackgroundColor(Color.RED);
                RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams)holder.name.getLayoutParams();
                params.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
                holder.name.setLayoutParams(params); //causes layout update
            }
        }



<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView xmlns:android="http://schemas.android.com/apk/res/android"
              android:id="@+id/list_item_name"
              android:layout_width="wrap_content"
              android:layout_height="match_parent"
              android:textSize="@dimen/list_ingredienti_size"
              android:focusable="false"
              android:text="testo"
              android:textColor="@drawable/selected_textcolor"
              android:gravity="center"
              android:background="@drawable/selected_background"
        />
</RelativeLayout>

第二

    @Override
    protected void onBindViewHolder(IngredienteViewHolder holder, int position, Ingrediente model) {
        holder.name.setText(model.getName());
        holder.setIngrediente(model);
        if (position % 2 == 0){
            holder.name.setBackgroundColor(Color.BLACK);
            RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams)holder.name.getLayoutParams();
            params.removeRule(RelativeLayout.ALIGN_PARENT_START);
            params.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
            holder.name.setLayoutParams(params); //causes layout update
        } else {
            holder.name.setBackgroundColor(Color.RED);
            RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams)holder.name.getLayoutParams();
            params.removeRule(RelativeLayout.ALIGN_PARENT_START);
            params.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
            holder.name.setLayoutParams(params); //causes layout update
        }
    }




<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView xmlns:android="http://schemas.android.com/apk/res/android"
              android:id="@+id/list_item_name"
              android:layout_width="wrap_content"
              android:layout_height="match_parent"
              android:layout_alignParentStart="true"
              android:textSize="@dimen/list_ingredienti_size"
              android:focusable="false"
              android:text="testo"
              android:textColor="@drawable/selected_textcolor"
              android:gravity="center"
              android:background="@drawable/selected_background"
        />
</RelativeLayout>