Question

在许多问题中，人们说“在onCreateViewHolder中调用OnClickListener。你不需要在onBindViewHolder上调用OnClickListener每个项目”

@Override
  public Viewholder onCreateViewHolder(ViewGroup parent, int viewType) {
     View v = LayoutInflater.from(parent.getContext()).inflate(itemLayout, parent, false);
     final ViewHolder holder = new ViewHolder(v);

     holder.itemView.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
             Log.d(TAG, "position = " + holder.getAdapterPosition());
         }
     });
     return new Viewholder(v);
  }

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

  }

但在Logcat中，始终显示“position = -1”

这不正确。

为什么我应该在onCreateViewHolder中调用onClickListener？

Answer 1

onCreateViewHolder中的
getAdapterPosition始终为“-1”

您应该 return holder 而不是 new Viewholder(v) 。

代码结构

@Override
  public Viewholder onCreateViewHolder(ViewGroup parent, int viewType) {
     View v = LayoutInflater.from(parent.getContext()).inflate(itemLayout, parent, false);
     final ViewHolder holder = new ViewHolder(v);

     holder.itemView.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
             Log.d(TAG, "position = " + holder.getAdapterPosition());
         }
     });
     return holder;
  }

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

  }

Answer 2

因为您正在返回新的ViewHolder而不是您设置点击侦听器的那个。

而不是return new Viewholder(v)，您应该return holder;

设置点击侦听器的更清晰的方法可以是

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    return new ViewHolder(LayoutInflater.from(parent.getContext()).inflate(
                R.layout.layout_item, parent, false));
}

public class ViewHolder extends RecyclerView.ViewHolder {

    private ImageView image;

    public ViewHolder(View itemView) {
        super(itemView);

        itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // do what you need to do. getAdapterPosition() is useful here
            }
        });
    }
}

Answer 3

onCreateViewHolder仅用于扩充布局资源，您不应在此处放置与持有者项目相关的任何方法。

相反，您必须使用onBindViewHolder获取holder.getAdapterPosition的值或设置onClickListeners等。

Answer 4

首先return new Viewholder(v)代替OnClickListener 您可以在ViewHolder中拥有getAdapterPosition()，并按class ViewHolder extends RecyclerView.ViewHolder{ public ViewHolder(View itemView) { super(itemView); itemView.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Log.d(TAG, "position = " + getAdapterPosition()); //do your stuff here } }); } }

获取排名

package de.gdv.sp.configuration;

import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import com.captcha.botdetect.web.servlet.CaptchaServlet;

@Configuration

public class CaptchaConfiguration extends WebApplicationInitializer {

    @Bean(name = "captchaServlet")
    public ServletRegistrationBean captchaServlet() {

        return new ServletRegistrationBean(new CaptchaServlet(), "/kontakt");
    }
}

onCreateViewHolder中的getAdapterPosition始终为“-1”

4 个答案: