ListView动态更新item的例子

1.ListViewUpdate.java文件:

package com.example;

import java.util.Random;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ListView;

public class ListViewUpdate extends Activity implements OnClickListener {
	
	private ListView lvDynamic;
	private ViewAdapter viewAdapter;
	private ItemListener listener;
	private static String[] data = new String[] { "机器化身", "第九区", "火星任务",
			"人工智能", "钢铁侠", "铁臂阿童木 ", "未来战士", "星际传奇", };
	private int selectedIndex = -1;

	public int getSelectedIndex() {
		return selectedIndex;
	}
	
	public void setSelectedIndex(int index){
		this.selectedIndex = index;
	}
	
	
	private int getImageResourceId() {
		int[] resourceIds = new int[] { R.drawable.item1, R.drawable.item2,
				R.drawable.item3, R.drawable.item4, R.drawable.item5 };
		return resourceIds[new Random().nextInt(resourceIds.length)];
	}
 
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		lvDynamic = (ListView) findViewById(R.id.lvDynamic);
		Button btnAddText = (Button) findViewById(R.id.btnAddText);
		Button btnAddImage = (Button) findViewById(R.id.btnAddImage);
		Button btnRemove = (Button) findViewById(R.id.btnRemove);
		Button btnRemoveAll = (Button) findViewById(R.id.btnRemoveAll);
		btnAddText.setOnClickListener(this);
		btnAddImage.setOnClickListener(this);
		btnRemove.setOnClickListener(this);
		btnRemoveAll.setOnClickListener(this);
		listener = new ItemListener(this);
		viewAdapter = new ViewAdapter(this);
		lvDynamic.setAdapter(viewAdapter);
		lvDynamic.setOnItemSelectedListener(listener);
	}

	@Override
	public void onClick(View view) {
		// TODO Auto-generated method stub
		switch (view.getId()) {
		case R.id.btnAddText:
			int randomNum = new Random().nextInt(data.length);
			viewAdapter.addText(data[randomNum]);
			break;
		case R.id.btnAddImage:
			viewAdapter.addImage(getImageResourceId());
			break;
		case R.id.btnRemove:
			viewAdapter.remove(selectedIndex);
			selectedIndex = -1;
			break;
		case R.id.btnRemoveAll:
			viewAdapter.removeAll();
			break;

		}
	}
}

2. ViewAdapter.java适配器文件

package com.example;

import java.util.ArrayList;
import java.util.List;
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.LinearLayout;
import android.widget.TextView;

public class ViewAdapter extends BaseAdapter {

	private Context context;
	private List textIdList = new ArrayList();

	public ViewAdapter(Context context) {
		this.context = context;
	}

	public int getCount() {
		return textIdList.size();
	}

	public Object getItem(int position) {
		return textIdList.get(position);
	}

	public long getItemId(int position) {
		// TODO Auto-generated method stub
		return 0;
	}

	public View getView(int position, View convertView, ViewGroup parent) {
		System.out.println("position2222----------------------->"+position);
		String inflater = Context.LAYOUT_INFLATER_SERVICE;
		LayoutInflater layoutInflater = (LayoutInflater) context
				.getSystemService(inflater);
		LinearLayout linearLayout = null;
		if (textIdList.get(position) instanceof String) {
			linearLayout = (LinearLayout) layoutInflater.inflate(R.layout.text,
					null);
			TextView textView = ((TextView) linearLayout
					.findViewById(R.id.textview));
			textView.setText(String.valueOf(textIdList.get(position)));
		} else if (textIdList.get(position) instanceof Integer) {
			linearLayout = (LinearLayout) layoutInflater.inflate(
					R.layout.image, null);
			ImageView imageView = (ImageView) linearLayout
					.findViewById(R.id.imageview);
			imageView.setImageResource(Integer.parseInt(String
					.valueOf(textIdList.get(position))));
		}
		return linearLayout;
	}

	public void addText(String text) {
		textIdList.add(text);
		notifyDataSetChanged();
	}
	
	public void addImage(int resId) {
		textIdList.add(resId);
		notifyDataSetChanged();
	}
	
	public void remove(int index) {
		if (index < 0)
			return;
		textIdList.remove(index);
		notifyDataSetChanged();
	}
	
	public void removeAll() {
		textIdList.clear();
		notifyDataSetChanged();
	}

}

3. ItemListener.java监听器:

package com.example;

import android.content.Context;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;

public class ItemListener implements OnItemSelectedListener {

	private Context con;
	
	public ItemListener(Context con){
		this.con = con;
	}
	@Override
	public void onItemSelected(AdapterView<?> arg0, View arg1, int position,
			long arg3) {
		// TODO Auto-generated method stub
		((ListViewUpdate)con).setSelectedIndex(position);
		
	}

	@Override
	public void onNothingSelected(AdapterView<?> arg0) {
		// TODO Auto-generated method stub
		
	}

}

4.最后是3个xml布局文件:

main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:orientation="vertical" android:layout_width="fill_parent"
	android:layout_height="fill_parent">
	<LinearLayout android:orientation="horizontal"
		android:layout_width="fill_parent" android:layout_height="wrap_content">
		<Button android:id="@+id/btnAddText" android:layout_width="wrap_content"
			android:layout_height="wrap_content" android:text="添加文本" />
		<Button android:id="@+id/btnAddImage" android:layout_width="wrap_content"
			android:layout_height="wrap_content" android:text="添加图像" />
		<Button android:id="@+id/btnRemove" android:layout_width="wrap_content"
			android:layout_height="wrap_content" android:text="删除当前项" />
		<Button android:id="@+id/btnRemoveAll" android:layout_width="wrap_content"
			android:layout_height="wrap_content" android:text="清空" />
	</LinearLayout>
	<ListView android:id="@+id/lvDynamic" android:layout_width="fill_parent"
		android:layout_height="fill_parent" android:cacheColorHint="#00000000" />
</LinearLayout>

image.xml:


<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:orientation="vertical" android:layout_width="fill_parent"
	android:layout_height="wrap_content">
	<ImageView android:id="@+id/imageview" android:layout_width="100dp"
		android:layout_height="100dp" android:padding="10dp"/>
</LinearLayout>

text.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:orientation="vertical" android:layout_width="fill_parent"
	android:layout_height="wrap_content">
	<TextView android:id="@+id/textview" android:layout_width="fill_parent"
		android:layout_height="wrap_content" android:padding="10dp"
		android:textAppearance="?android:attr/textAppearanceLarge" />
</LinearLayout>

在附上几个图片文件,供测试使用: