Android ListView item 选中高亮显示

很多时候我们在使用ListView的时候，当用户点击某一个Item之后，需要让它的背景色和字体颜色都发生改变以示区别，本例实现了这个功能。

思路：在Adapter类中保存一个变量，记录当前用户选择的item的位置，并在getView 中进行判断， 在ListView的item点击事件 onItemClick 方法中更新UI，并记录点击item的位置。

实现的效果如下：



主界面 MainActivity.java

package com.example.selecthighlight;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {

private ListView mListView;
private List<Data> dataList = new ArrayList<Data>();
private char[] chs = { 'A', 'B', 'C', 'D', 'E', 'M', 'L', 'F', 'X', 'W',
'Z' };
private HightKeywordsAdapter mAdapter;

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

findViewById();
initListViewData();
setListener();
}

private void setListener() {

mAdapter = new HightKeywordsAdapter();

mListView.setAdapter(mAdapter);
mListView.setOnItemClickListener(new OnItemClickListener() {

@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {

Toast.makeText(getApplicationContext(), "click " + position,
Toast.LENGTH_SHORT).show();

mAdapter.setSelectItem(position); // 记录当前选中的item

mAdapter.notifyDataSetInvalidated();	//更新UI界面
// mAdapter.notifyDataSetChanged();
}

});
}

private void initListViewData() {

for (char ch : chs) {

for (int i = 0; i < 5; i++) {

Data data = new Data(String.valueOf(ch) + "中国",
String.valueOf(ch) + i, String.valueOf(ch));

dataList.add(data);
}
}

}

private void findViewById() {
mListView = (ListView) findViewById(R.id.mListView);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

/**
* Customize Adapter, so that realize highlighted keywords
*/
private class HightKeywordsAdapter extends BaseAdapter {

private int selectItem = -1;

public void setSelectItem(int selectItem) {
this.selectItem = selectItem;
}

@Override
public int getCount() {

return dataList.size();
}

@Override
public Object getItem(int position) {

return dataList.get(position);
}

@Override
public long getItemId(int position) {

return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {

View view;
ViewHolder holder;

if (convertView == null) {

holder = new ViewHolder();

view = View.inflate(getApplicationContext(),
R.layout.list_item, null);

holder.tv_name = (TextView) view.findViewById(R.id.tv_name);
holder.tv_en = (TextView) view.findViewById(R.id.tv_en);
holder.tv_sen = (TextView) view.findViewById(R.id.tv_sen);

view.setTag(holder);
} else {
view = convertView;
holder = (ViewHolder) view.getTag();
}

if (position == selectItem) {	//选中状态 高亮
view.setBackgroundColor(Color.YELLOW);
holder.tv_name.setTextColor(getResources().getColor(R.color.color_green));
holder.tv_en.setTextColor(getResources().getColor(R.color.color_green));
holder.tv_sen.setTextColor(getResources().getColor(R.color.color_green));
} else {	//正常状态
view.setBackgroundColor(getResources().getColor(R.color.color_blue));
holder.tv_name.setTextColor(getResources().getColor(R.color.color_white));
holder.tv_en.setTextColor(getResources().getColor(R.color.color_white));
holder.tv_sen.setTextColor(getResources().getColor(R.color.color_white));
}

Data data = dataList.get(position);

holder.tv_name.setText(data.getName());

holder.tv_en.setText(data.getEn());
holder.tv_sen.setText(data.getSen());

return view;
}
}

static class ViewHolder {
public TextView tv_name;
public TextView tv_en;
public TextView tv_sen;

}

}

主界面布局文件 activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
android:background="@drawable/bg">

<ListView
android:id="@+id/mListView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:cacheColorHint="@android:color/transparent"/>

</RelativeLayout>

数据Bean Data.java

package com.example.selecthighlight;

public class Data {
private String name;
private String en;
private String sen;

public Data(String name, String en, String sen) {
this.name = name;
this.en = en;
this.sen = sen;
}

public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEn() {
return en;
}
public void setEn(String en) {
this.en = en;
}
public String getSen() {
return sen;
}
public void setSen(String sen) {
this.sen = sen;
}

}

public void notifyDataSetChanged ()

           该方法内部实现了在每个观察者上面调用onChanged事件。每当发现数据集有改变的情况，或者读取到数据的新状态时，就会调用此方法。notifyDataSetInvalidated()，会重绘控件（还原到初始状态）

public void notifyDataSetInvalidated ()

           该方法内部实现了在每个观察者上面调用onInvalidated事件。每当发现数据集监控有改变的情况，就会调用此方法。notifyDataSetChanged()，重绘当前可见区域

如果大家有更好的实现方式，记得告诉我哦！