android ListView

1 得到选择item的值

        mContactList.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Cursor c = (Cursor) mContactList.getItemAtPosition(position);
String name = c.getString(c.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
}
});
//根据点击位置取得item,转换为Cursor
        mContactList.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
cursor.moveToPosition(position);
String name = cursor.getString(
cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
}
});

//cursor为外部查询得到,在内存中保存一个cursor,根据点击位置去cursor取值

 2 自定义ListView

  1)首先需要自定义item的layout

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation
="horizontal"
android:layout_width
="match_parent"
android:layout_height
="match_parent">

<ImageView android:id="@+id/icon"
android:layout_width
="48dip"
android:layout_height
="48dip"/>

<TextView android:id="@+id/text"
android:layout_gravity
="center_vertical"
android:layout_width
="0dip"
android:layout_weight
="1.0"
android:layout_height
="wrap_content"/>

</LinearLayout>


  2) 自定义Adapter,并且在构造函数中传值

package com.example.android.contactmanager;

import android.content.Context;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class ContactItemAdapter extends BaseAdapter{

private LayoutInflater mInflater;
private Bitmap mIcon1;
private Bitmap mIcon2;

private Cursor cursor=null;

public ContactItemAdapter(Context context,Cursor cursor) {
this.cursor=cursor;
// Cache the LayoutInflate to avoid asking for a new one each time.
mInflater = LayoutInflater.from(context);

// Icons bound to the rows.
mIcon1 = BitmapFactory.decodeResource(context.getResources(), R.drawable.icon48x48_1);
mIcon2 = BitmapFactory.decodeResource(context.getResources(), R.drawable.icon48x48_2);
}

/**
* The number of items in the list is determined by the number of speeches
* in our array.
*
*
@see android.widget.ListAdapter#getCount()
*/
public int getCount() {
return cursor.getCount();
}

/**
* Since the data comes from an array, just returning the index is
* sufficent to get at the data. If we were using a more complex data
* structure, we would return whatever object represents one row in the
* list.
*
*
@see android.widget.ListAdapter#getItem(int)
*/
public Object getItem(int position) {
return position;
}

/**
* Use the array index as a unique id.
*
*
@see android.widget.ListAdapter#getItemId(int)
*/
public long getItemId(int position) {
return position;
}

/**
* Make a view to hold each row.
*
*
@see android.widget.ListAdapter#getView(int, android.view.View,
* android.view.ViewGroup)
*/
public View getView(int position, View convertView, ViewGroup parent) {
// A ViewHolder keeps references to children views to avoid unneccessary calls
// to findViewById() on each row.
ViewHolder holder;

// When convertView is not null, we can reuse it directly, there is no need
// to reinflate it. We only inflate a new View when the convertView supplied
// by ListView is null.
if (convertView == null) {
convertView = mInflater.inflate(R.layout.test_list_item_icon_text, null);

// Creates a ViewHolder and store references to the two children views
// we want to bind data to.
holder = new ViewHolder();
holder.text = (TextView) convertView.findViewById(R.id.text);
holder.icon = (ImageView) convertView.findViewById(R.id.icon);

convertView.setTag(holder);
} else {
// Get the ViewHolder back to get fast access to the TextView
// and the ImageView.
holder = (ViewHolder) convertView.getTag();
}

cursor.moveToPosition(position);

// Bind the data efficiently with the holder.
holder.text.setText(cursor.getString(1));
holder.icon.setImageBitmap((position & 1) == 1 ? mIcon1 : mIcon2);

return convertView;
}

static class ViewHolder {
TextView text;
ImageView icon;
}

}


  3)在Activity中调用

  

   public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Cursor cursor=getContacts();
setListAdapter(new ContactItemAdapter(this,cursor));
}

资料:

       ListView使用初步

       ListView添加事件并获取选中项的值

原文地址:https://www.cnblogs.com/myparamita/p/2257443.html