ListView的使用方法


ListView是Android软件开发中非常重要组件之一,基本上是个软件基本都会使用ListView ,今天我通过一个demo来教大家怎么样使用ListView组件 绘制出漂亮的列表,说道ListView就不得不说Adapter适配器,因为只有通过Adapter才可以把列表中的数据映射到ListView中。
在android的开发中最Adapter 一共可以分为
ArrayAdapter<T>,
BaseAdapter,
CursorAdapter,
HeaderViewListAdapter,
ResourceCursorAdapter,
SimpleAdapter,
SimpleCursorAdapter,
WrapperListAdapter

软件开发中最常用的有ArrayAdapter<T>, BaseAdapter, SimpleAdapter,今天用一段代码向大家诠释如何使用ListView控件。
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1.简单的ListView

在List列表中如果不存在过于复杂的东西 我们可以直接去new ArrayAdapter() 来绘制列表,无须继承ArrayAdapter,重写它的方法。但是如果列表中过于复杂的话就需要使用自定义布局来实现List列表。
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public class SimpleList extends ListActivity {

private String[] mListStr = {"姓名:雨松MOMO","性别:男","年龄:25","居住地:北京","邮箱:xuanyusong@gmail.com"};

ListView mListView = null;

@Override

protected void onCreate(Bundle savedInstanceState) {

mListView = getListView();

setListAdapter(new ArrayAdapter<String>(this,

android.R.layout.simple_list_item_1, mListStr));

mListView.setOnItemClickListener(new OnItemClickListener() {

@Override

public void onItemClick(AdapterView<?> adapterView, View view, int position,

long id) {

Toast.makeText(SimpleList.this,"您选择了" + mListStr[position], Toast.LENGTH_LONG).show();

}

});



super.onCreate(savedInstanceState);

}

}
2.带标题的ListView列表

使用 simpleAdapter 需要注意的是须要用Map<String,Object> item 来保存列表中每一项的显示的title与text , new SimpleAdapter的时候将map中的数据写入 ,程序就会帮我们绘制列表了。
3.gif
public class TitleList extends ListActivity {

private String[] mListTitle = { "姓名", "性别", "年龄", "居住地","邮箱"};

private String[] mListStr = { "雨松MOMO", "男", "25", "北京",

"xuanyusong@gmail.com" };

ListView mListView = null;

ArrayList<Map<String,Object>> mData= new ArrayList<Map<String,Object>>();;



@Override

protected void onCreate(Bundle savedInstanceState) {

mListView = getListView();



int lengh = mListTitle.length;

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

Map<String,Object> item = new HashMap<String,Object>();

item.put("title", mListTitle[i]);

item.put("text", mListStr[i]);

mData.add(item);    

}

SimpleAdapter adapter = new SimpleAdapter(this,mData,android.R.layout.simple_list_item_2,

new String[]{"title","text"},new int[]{android.R.id.text1,android.R.id.text2});

setListAdapter(adapter);

mListView.setOnItemClickListener(new OnItemClickListener() {

@Override

public void onItemClick(AdapterView<?> adapterView, View view, int position,

long id) {

Toast.makeText(TitleList.this,"您选择了标题:" + mListTitle[position] + "内容:"+mListStr[position], Toast.LENGTH_LONG).show();

}

});

super.onCreate(savedInstanceState);

}

}
 
 
3.带图片的ListView列表

使用 simpleAdapter 来操作 但是构造simpleAdapter的时候须要使用我们自己写的布局来完成 ,因为系统的布局已经不能满足需求了,同样Map<String,Object> item 来保存列表中每一项须要的显示内容 如 图片 标题 内容等。

4.gif
添加我们自己的列表布局 图片 标题 内容
<?xml version="1.0" encoding="utf-8"?>



<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="fill_parent" android:layout_height="?android:attr/listPreferredItemHeight">

<ImageView android:id="@+id/p_w_picpath"

android:layout_width="wrap_content" android:layout_height="fill_parent"

android:layout_alignParentTop="true" android:layout_alignParentBottom="true"

android:adjustViewBounds="true"

android:padding="2dip" />

<TextView android:id="@+id/title"

android:layout_width="wrap_content" android:layout_height="wrap_content"

android:layout_toRightOf="@+id/p_w_picpath"

android:layout_alignParentRight="true" android:layout_alignParentTop="true"

android:layout_above="@+id/text"

android:layout_alignWithParentIfMissing="true" android:gravity="center_vertical"

android:textSize="15dip" />

<TextView android:id="@+id/text"

android:layout_width="fill_parent" android:layout_height="wrap_content"

android:layout_toRightOf="@+id/p_w_picpath"

android:layout_alignParentBottom="true"

android:layout_alignParentRight="true" android:singleLine="true"

android:ellipsize="marquee"    

android:textSize="20dip" />

</RelativeLayout>

 
 
 
public class IconList extends ListActivity {

private String[] mListTitle = { "姓名", "性别", "年龄", "居住地","邮箱"};

private String[] mListStr = { "雨松MOMO", "男", "25", "北京",

"xuanyusong@gmail.com" };

ListView mListView = null;

ArrayList<Map<String,Object>> mData= new ArrayList<Map<String,Object>>();;



@Override

protected void onCreate(Bundle savedInstanceState) {

mListView = getListView();



int lengh = mListTitle.length;

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

Map<String,Object> item = new HashMap<String,Object>();

item.put("p_w_picpath", R.drawable.jay);

item.put("title", mListTitle[i]);

item.put("text", mListStr[i]);

mData.add(item);    

}

SimpleAdapter adapter = new SimpleAdapter(this,mData,R.layout.iconlist,

new String[]{"p_w_picpath","title","text"},new int[]{R.id.p_w_picpath,R.id.title,R.id.text});

setListAdapter(adapter);

mListView.setOnItemClickListener(new OnItemClickListener() {

@Override

public void onItemClick(AdapterView<?> adapterView, View view, int position,

long id) {

Toast.makeText(IconList.this,"您选择了标题:" + mListTitle[position] + "内容:"+mListStr[position], Toast.LENGTH_LONG).show();

}

});

super.onCreate(savedInstanceState);

}

}
4.自定义布局BaseAdapter修改列表颜色

因为通过直接 构造系统的布局来绘制列表方法肯定是有限的,所以我们需要重写绘制方法 ,写一个类去继承BaseAdapter 并实现这个类中的方法,listView在一开始绘制的时候首先会调用getCout()方法得到绘制次数 ,然后会实例化自己定义的BaseAdapter通过getView()方法一层一层绘制ListView,所以我们可以在这里面根据position(当前绘制的ID)来任意的修改绘制的内容,做出好看漂亮的ListView,下面这个例子我通过重写getView修改每个列表的颜色 并且实现用户选中后成高亮状态。
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  1. public class ColorList extends ListActivity {

    private String[] mListTitle = { "姓名", "性别", "年龄", "居住地","邮箱"};

    private String[] mListStr = { "雨松MOMO", "男", "25", "北京",

    "xuanyusong@gmail.com" };

    ListView mListView = null;

    MyListAdapter myAdapter = null;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

    mListView = getListView();

    myAdapter = new MyListAdapter(this);

    setListAdapter(myAdapter);

    mListView.setOnItemClickListener(new OnItemClickListener() {

    @Override

    public void onItemClick(AdapterView<?> adapterView, View view, int position,

    long id) {

    View v=adapterView.getChildAt(position);

    v.setBackgroundColor(Color.RED);

    Toast.makeText(ColorList.this,"您选择了" + mListStr[position], Toast.LENGTH_LONG).show();

    }

    });



    super.onCreate(savedInstanceState);

    }



    class MyListAdapter extends BaseAdapter {

    private int[] colors = new int[] { 0xff626569, 0xff4f5257 };

    public MyListAdapter(Context context) {

    mContext = context;

    }



    public int getCount() {

    return mListStr.length;

    }



    @Override

    public boolean areAllItemsEnabled() {

    return false;

    }



    public Object getItem(int position) {

    return position;

    }



    public long getItemId(int position) {

    return position;

    }



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

    ImageView iamge = null;

    TextView title = null;

    TextView text = null;

    if (convertView == null) {

    convertView = LayoutInflater.from(mContext).inflate(R.layout.colorlist, null);

    iamge = (ImageView) convertView.findViewById(R.id.color_p_w_picpath);

    title =(TextView) convertView.findViewById(R.id.color_title);

    text= (TextView) convertView.findViewById(R.id.color_text);

    }    

    int colorPos = position % colors.length;

    convertView.setBackgroundColor(colors[colorPos]);

    title.setText(mListTitle[position]);

    text.setText(mListStr[position]);

    iamge.setImageResource(R.drawable.jay);

    return convertView;

    }



    private Context mContext;

    }

    }
5.自定义布局ArrayAdapter
ArrayAdapter是BaseAdapter的子类,ArrayAdapter不仅具有BaseAdapter的所有方法还自定义了一些新的方法来处理列表项,所以单纯的从功能能上来讲ArrayAdapter远远强与BaseAdapter,如果是绘制一些数量比较少的列表建议使用BaseAdapter 如果绘制一些比较复杂的列表项 并且列表项很多的 建议使用ArrayAdapter。
6.gif
<?xml version="1.0" encoding="utf-8"?>



<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="fill_parent" android:layout_height="wrap_content">

<Button

android:id="@+id/array_button"

android:layout_width="wrap_content"    

android:layout_height="wrap_content"

android:text="一个按钮"

/>

<ImageView android:id="@+id/array_p_w_picpath"

android:layout_toRightOf="@+id/array_button"

android:layout_width="wrap_content" android:layout_height="fill_parent"

android:layout_alignParentTop="true" android:layout_alignParentBottom="true"

android:adjustViewBounds="true"

android:padding="2dip" />

<TextView android:id="@+id/array_title"

android:layout_width="fill_parent" android:layout_height="wrap_content"

android:layout_toRightOf="@+id/array_p_w_picpath"

android:layout_alignParentBottom="true"

android:layout_alignParentRight="true" android:singleLine="true"

android:ellipsize="marquee"    

android:textSize="15dip" />

<TextView android:id="@+id/array_text"

android:layout_width="fill_parent" android:layout_height="wrap_content"

android:layout_toRightOf="@+id/array_p_w_picpath"

android:layout_below="@+id/array_title"

android:layout_alignParentBottom="true"

android:layout_alignParentRight="true"    

android:singleLine="true"

android:ellipsize="marquee"    

android:textSize="20dip" />



</RelativeLayout>
 
public class ArrayList extends ListActivity {

private String[] mListTitle = { "姓名", "性别", "年龄", "居住地","邮箱"};

private String[] mListStr = { "雨松MOMO", "男", "25", "北京",

"xuanyusong@gmail.com" };

ListView mListView = null;

MyListAdapter myAdapter = null;

ArrayList arrayList = null;

@Override

protected void onCreate(Bundle savedInstanceState) {

arrayList = this;

mListView = getListView();

myAdapter = new MyListAdapter(this,R.layout.arraylist);

setListAdapter(myAdapter);

super.onCreate(savedInstanceState);

}



public class MyListAdapter extends ArrayAdapter<Object> {

int mTextViewResourceID = 0;

private Context mContext;

public MyListAdapter(Context context, int textViewResourceId) {

super(context, textViewResourceId);

mTextViewResourceID = textViewResourceId;

mContext = context;

}



private int[] colors = new int[] { 0xff626569, 0xff4f5257 };



public int getCount() {

return mListStr.length;

}



@Override

public boolean areAllItemsEnabled() {

return false;

}



public Object getItem(int position) {

return position;

}



public long getItemId(int position) {

return position;

}



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

ImageView iamge = null;

TextView title = null;

TextView text = null;

Button button = null;

if (convertView == null) {

convertView = LayoutInflater.from(mContext).inflate(

mTextViewResourceID, null);

iamge = (ImageView) convertView.findViewById(R.id.array_p_w_picpath);

title = (TextView) convertView.findViewById(R.id.array_title);

text = (TextView) convertView.findViewById(R.id.array_text);

button = (Button)convertView.findViewById(R.id.array_button);

button.setOnClickListener(new OnClickListener() {



@Override

public void onClick(View arg0) {

Toast.makeText(arrayList,"您点击的第"+position +"个按钮", Toast.LENGTH_LONG).show();



}

});

}

int colorPos = position % colors.length;

convertView.setBackgroundColor(colors[colorPos]);

title.setText(mListTitle[position]);

text.setText(mListStr[position]);

if(colorPos == 0)

iamge.setImageResource(R.drawable.jay);

else

iamge.setImageResource(R.drawable.p_w_picpath);

return convertView;

}

}

}