Android：动态更改Listview中的图像

我有一个由以下 xml 定义的列表视图。我需要切换图像当用户单击任何行时，在运行时会出现在列表中。我怎样才能实现这个目标？非常感谢任何帮助。谢谢

//list_item.xml
<?xml version="1.0" encoding="UTF-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/play" 
android:id="@+id/img"
/> 
<TextView 
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center_vertical"
android:id="@+id/txt"
/>
</LinearLayout>

您可以找到该项目的img通过调用查看findViewById http://developer.android.com/reference/android/view/View.html#findViewById%28int%29关于第二个参数（即View单击的项目的）内onItemClick http://developer.android.com/reference/android/widget/AdapterView.OnItemClickListener.html#onItemClick%28android.widget.AdapterView%3C?%3E,%20android.view.View,%20int,%20long%29处理程序：

public void onItemClick(AdapterView parentView, View clickedItemView, int pos, long id)
{
    ImageView imageView = (ImageView) clickedItemView.findViewById(R.id.img);
    // ...
}

EDIT:请注意 Android 重用列表项View对象（也称为视图回收），因此需要存储每个项目的切换状态以供以后使用。每当列表项视图绑定到要显示的列表项时，都需要访问每个项目的切换状态。

例如，以下是单击时切换每个项目的图像的活动的工作示例：

import java.util.Arrays;
import java.util.List;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListView;

public class SO4539968TestCaseActivity extends Activity {
    private static final List<String> ITEM_TEXTS = Arrays.asList(new String[] {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13"});

    private boolean[] itemToggled;

    private class MyArrayAdapter<T> extends ArrayAdapter<T>
    {
        public MyArrayAdapter(Context context, int resource, int textViewResourceId, List<T> objects) {
            super(context, resource, textViewResourceId, objects);
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View itemView = super.getView(position, convertView, parent);
            ImageView imageView = (ImageView) itemView.findViewById(R.id.img);
            imageView.setImageResource(itemToggled[position] ? R.drawable.on : R.drawable.off);
            return itemView;
        }
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        itemToggled = new boolean[ITEM_TEXTS.size()];
        Arrays.fill(itemToggled, false);

        ListView listView = (ListView) findViewById(R.id.list_view0);
        listView.setAdapter(new MyArrayAdapter<String>(this, R.layout.list_item, R.id.txt, ITEM_TEXTS));
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            public void onItemClick(AdapterView<?> listView, View itemView, int position, long id) {
                itemToggled[position] = ! itemToggled[position];

                ImageView imageView = (ImageView) itemView.findViewById(R.id.img);
                imageView.setImageResource(itemToggled[position] ? R.drawable.on : R.drawable.off);
            }
        });
    }
}

要学习的重要部分是onItemClick回调和覆盖getView in MyArrayAdapter.

The getView http://developer.android.com/reference/android/widget/Adapter.html#getView%28int,%20android.view.View,%20android.view.ViewGroup%29的方法Adapter类负责膨胀项目布局。在这个例子中，我称getView超类的方法最初准备项目视图，但随后我确保正确设置项目的资源 IDimg view:

imageView.setImageResource(itemToggled[position] ? R.drawable.on : R.drawable.off);

也可以看看：开发 Android 应用程序 – 陷阱和怪癖 https://jonhoo.wordpress.com/2010/07/17/developing-applications-for-android-gotchas-and-quirks/