如何在 Android 中单击 ListView 行时使 ImageView 可见和不可见？

Question

我有一个ListView，它是使用SimpleAdapter 生成的。我在与SimpleAdapter 一起使用的xml 文件中有一个textview 和一个ImageView。图像视图首先设置为不可见。单击 Listview 中的一行时，Imageview 变为可见。我想做的是：

如果我在 Listview 中有 4 行并且如果我单击第 1 行，那么 ImageView 应该在第 1 行可见，然后如果我单击第 2 行，则 imageview 应该从第 1 行变得不可见，并且应该只在第 2 行可见。

我已经完成了以下操作，但它的工作方式如下：

如果我单击第 1 行，则 ImageView 在第 1 行可见。然后，如果我单击第 2 行，则 ImageView 在第 2 行上可见，并且在第 1 行上也可见。我想让它从第 1 行不可见，并且只显示在点击的行上。

谁能一步一步指导我如何做到这一点。我的代码和xml如下：

myactivity.class

   final ListAdapter k=new SimpleAdapter(getActivity(),val,R.layout.senttaskdata2,new String[]{"rname"},new int[]{R.id.textView1})
  {

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        final View v = super.getView(position, convertView, parent);
                    ImageView im=(ImageView)v.findViewById(R.id.ImageView3);
                    @Override
            public void onItemClick(AdapterView<?> arg0, View arg1,
                    int arg2, long arg3) {
                // TODO Auto-generated method stub
                        ImageView im=(ImageView)arg1.findViewById(R.id.ImageView3);
                       setVisibility(arg1.VISIBLE);
                    });
        return v;
    }

  };
  sent.setAdapter(k);

senttaskdata2.xml

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

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="70dp"

    android:background="@android:color/transparent" >

   <ImageView
        android:id="@+id/imageView3"
        android:layout_width="48dp"
        android:layout_height="48dp"
        android:layout_alignParentLeft="true"
        android:layout_centerVertical="true"
        android:layout_marginLeft="8dp"
        android:src="@drawable/test2" />

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textView2"
        android:layout_below="@+id/textView2"
        android:text="TextView"
        android:textColor="@android:color/darker_gray"
        android:textSize="11sp" />

      </RelativeLayout>

  </LinearLayout>

Answer 1

我有同样的问题，我找到了一个简单的方法。

首先，在您的自定义适配器中

public class MyAdapter extends BaseAdapter {

    private int selectedIndex;
    private boolean visible;

// omitted code

}

// omitted code

public View getView(int index, View view, ViewGroup parent) {

        TextView textView= (TextView) view.findViewById(R.id.text_view);
        ImageView imgView = (ImageView) view.findViewById(R.id.image_view);

        textView.setText("some text");

        if(index == selectedIndex) {
            imgView .setVisibility(View.VISIBLE);
        } else {
            imgView .setVisibility(View.INVISIBLE);
        }

        return view;
    }

第二，在你的活动中

 public void onCreate(Bundle bundle) {

    // omitted code
        listView.setOnItemClickListener(new OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapter, View view,
                    int position, long id) {

                // change index of selected item
                fontAdapter.setSelectedIndex(position);
                fontAdapter.notifyDataSetChanged();
            }

        });
   // omitted code
   }

Answer 2

试试这个我已经实现了我自己的适配器，而不是使用简单适配器

ListAdapter.java

package com.stackoverflow.listviewanswer;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class ListAdapter extends BaseAdapter
{

    private boolean[] mVisibilityList = null;
    private String[] mNameList = null;
    private Context mContext = null;
    private LayoutInflater mInflater = null;

    public ListAdapter(Context iContext, boolean[] iVisibilityList, String[] iNameList)
    {
        mVisibilityList = iVisibilityList;
        mContext = iContext;
        mInflater = LayoutInflater.from(mContext);
        mNameList = iNameList;
    }

    public void setVisibilityList(boolean[] iVisibilityList)
    {
        mVisibilityList = iVisibilityList;
    }

    @Override
    public int getCount()
    {

        return mVisibilityList.length;
    }

    @Override
    public Object getItem(int iPosition)
    {

        return mVisibilityList[iPosition];
    }

    @Override
    public long getItemId(int iPosition)
    {

        return iPosition;
    }

    @Override
    public View getView(int iPosition, View iConvertView, ViewGroup iViewGroup)
    {
        Holder holder = new Holder();

        if (iConvertView == null)
        {
            iConvertView = mInflater.inflate(R.layout.list, null);
            holder.mImageView = (ImageView) iConvertView.findViewById(R.id.imageView3);
            holder.mTextView = (TextView) iConvertView.findViewById(R.id.textView1);
            iConvertView.setTag(holder);

        }
        else
        {
            holder = (Holder) iConvertView.getTag();
        }

        // SET DATA
        if (mVisibilityList[iPosition])
        {
            holder.mImageView.setVisibility(View.VISIBLE);
        }
        else
        {
            holder.mImageView.setVisibility(View.INVISIBLE);

            // OR
            // holder.mImageView.setVisibility(View.GONE);
            // Use as per your needs
        }

        holder.mTextView.setText(mNameList[iPosition]);

        return iConvertView;
    }

    private class Holder
    {
        TextView mTextView = null;
        ImageView mImageView = null;
    }

}

MainActivity.java

package com.stackoverflow.listviewanswer;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.AdapterView.OnItemClickListener;

public class MainActivity extends Activity implements OnItemClickListener
{
    ListView mListView = null;
    boolean[] mVisisbilityList = { false, false, false, false };
    String[] mNameList = { "TextView 1", "TextView 2", "TextView 3", "TextView 4" };
    ListAdapter adapter = null;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mListView = (ListView) findViewById(R.id.list_view);
        mListView.setOnItemClickListener(this);

        adapter = new ListAdapter(this, mVisisbilityList, mNameList);

        mListView.setAdapter(adapter);
    }

    @Override
    public void onItemClick(AdapterView<?> iAdapterView, View iView, int iPosition, long iId)
    {
        for (int i = 0; i < 4; i++)
        {
            mVisisbilityList[i] = false;
        }
        mVisisbilityList[iPosition] = true;

        adapter.setVisibilityList(mVisisbilityList);

        adapter.notifyDataSetChanged();

    }

}

list.xml 与您的 senttaskdata2.xml 相同