自定义适配器
接着昨天的内容，如果想要定义更复杂的ListView怎么办，如果需要在列表中加入图片选择框以及按钮呢？我们改如何定义？修改布局文件已经不够用了，现在我们需要自定义适配器
首先新建一个·Activity
public class MainActivity extends ListActivity {
String[] strs = {"aa","xx","ss","dd","ff","gg","hh","jj"};
private ListView listview;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
我们在activity_main布局中放一个listview就可以了
<ListView 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" android:id="@+id/list_view" tools:context=".MainActivity" > </ListView>
现在获取布局在activity显示出来
listview.setAdapter(new ArrayAdapter(this, android.R.layout.simple_list_item_1, strs)); listview.setOnItemClickListener(listener); listview.setAdapter(new MyAdapter());
如果想添加按钮，像昨天一样，我们依然可以使用昨天的方法设置权重
<LinearLayout 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:orientation="vertical"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/lianxi_ren" android:layout_weight="0"/> <ListView android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/list_view" android:layout_weight="1"></ListView> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/button" android:text="button" android:layout_weight="0"/> </LinearLayout>
接下来我们开始自定义布局，丰富我们listview每一行的元素，现在我们数组适配器之能是一行textview
我们现在使用自定义适配器来改变我们的listview
首先我们把刚才的数组适配器注释掉 ，获取当前控件id
listview= (ListView) findViewById(R.id.list_view); // listview.setAdapter(new ArrayAdapter(this, android.R.layout.simple_list_item_1, strs)); // listview.setOnItemClickListener(listener); listview.setAdapter(new MyAdapter());
下面构建一个新的类MyAdpater继承BaseAdapter
public class MyAdapter extends BaseAdapter{
@Override
public int getCount() {
// TODO Auto-generated method stub
return 0;
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return null;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
return 0;
}
}
我们在这里定义显示的ListView行数
public int getCount() {
// TODO Auto-generated method stub
return 5;
}
先显示5行，通过getview来显示每一行的内容
@Override
public View getView(int position, View convertView, ViewGroup parent) {
TODO Auto-generated method stub
ImageView image = new ImageView (MainActivity.this);
image .setImageResource(R.drawable.ic_launcher);
System.out.println("getView"+position);
return image;
}
position行号
convertView当前行view
ViewGroup整体的listview
接下来我们设置更复杂的布局
先修改布局文件
<LinearLayout 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:orientation="vertical"> <TextView android:id="@+id/name" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="mjl" /> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/image" android:src="@drawable/ic_launcher" /> <CheckBox android:id="@+id/check" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <Button android:id="@+id/button" android:layout_width="wrap_content" android:layout_height="wrap_content"/> </LinearLayout>
在getView中获取显示出来
View view =View.inflate(MainActivity.this, R.layout.activity_main, null); return view;
下面展示出来所有代码
package com.example.listview;
import android.os.Bundle;
import android.app.Activity;
import android.app.ListActivity;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
public class MainActivity extends ListActivity {
String[] strs = {"aa","xx","ss","dd","ff","gg","hh","jj"};
private ListView listview;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listview= (ListView) findViewById(R.id.list_view);
// listview.setAdapter(new ArrayAdapter(this, android.R.layout.simple_list_item_1, strs));
// listview.setOnItemClickListener(listener);
listview.setAdapter(new MyAdapter());
}
public class MyAdapter extends BaseAdapter{
@Override
public int getCount() {
// TODO Auto-generated method stub
return 3;
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return null;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
// ImageView image = new ImageView (MainActivity.this);
// image .setImageResource(R.drawable.ic_launcher);
// System.out.println("getView"+position);
View view =View.inflate(MainActivity.this, R.layout.activity_main, null);
// return image;
return view;
}
}
}
第一部分布局
<LinearLayout 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:orientation="vertical"> <TextView android:id="@+id/name" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="mjl" /> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/image" android:src="@drawable/ic_launcher" /> <CheckBox android:id="@+id/check" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <Button android:id="@+id/button" android:layout_width="wrap_content" android:layout_height="wrap_content"/> </LinearLayout>
第二部分
<LinearLayout 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:orientation="vertical"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/lianxi_ren" android:layout_weight="0"/> <ListView android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/list_view" android:layout_weight="1"></ListView> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/button" android:text="button" android:layout_weight="0"/> </LinearLayout> <!-- <ListView 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" android:id="@+id/list_view" tools:context=".MainActivity" > </ListView> -->