Fatal编程技术网
  • android/
  • Android 在没有联系人图像可用时显示图像

Android 在没有联系人图像可用时显示图像

android

Android 在没有联系人图像可用时显示图像,android,contact,Android,Contact,我已经编写了一个应用程序，它可以简单地显示手机上所有可用的联系人。该应用程序运行良好。它可以检索联系人图像并显示联系人姓名。然而，在滚动列表时，应用程序有些滞后。我想知道如何消除这种滞后。同时，我想在没有联系人图像的情况下显示一个图像。我尝试创建一个布尔标志，告诉我联系人图像光标是否为空，如果为空，则我将该标志（image_found）设置为false，然后尝试使用setImageResource设置图像，但它不起作用。嗯，然后我想当没有图像的时候，blob对象可能会得到一个空值，但它也不起作用

我已经编写了一个应用程序，它可以简单地显示手机上所有可用的联系人。该应用程序运行良好。它可以检索联系人图像并显示联系人姓名。然而，在滚动列表时，应用程序有些滞后。我想知道如何消除这种滞后。同时，我想在没有联系人图像的情况下显示一个图像。我尝试创建一个布尔标志，告诉我联系人图像光标是否为空，如果为空，则我将该标志（image_found）设置为false，然后尝试使用setImageResource设置图像，但它不起作用。嗯，然后我想当没有图像的时候，blob对象可能会得到一个空值，但它也不起作用。这是我的邮件活动代码

package legacy_systems.aggregatedcontactlist;

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

import android.os.Bundle;
import android.provider.ContactsContract;
import android.support.v4.widget.CursorAdapter;
import android.support.v4.widget.SimpleCursorAdapter;
import android.app.ListActivity;
import android.content.Intent;
import android.database.Cursor;
import android.view.Menu;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

public class MainActivity extends ListActivity{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        Cursor c = getContentResolver().query(ContactsContract.Contacts.CONTENT_URI, 
                                              null, 
                                              null, 
                                              null, 
                                              ContactsContract.Contacts.DISPLAY_NAME+" ASC");

        ArrayList<String> con_ids = new ArrayList<String>();
        if(c!=null)
        {
            for(c.moveToFirst();!c.isAfterLast();c.moveToNext()){
                con_ids.add(c.getString(c.getColumnIndex(ContactsContract.Contacts._ID)));
            }
        }



        ListView ls = getListView();

        MyAdapter ada = new MyAdapter(this, R.layout.listview, con_ids);

        ls.setAdapter(ada);
    }

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


}

package legacy\u systems.aggregatedcontactlist；
导入java.util.ArrayList；
导入java.util.List；
导入android.os.Bundle；
导入android.provider.contacts合同；
导入android.support.v4.widget.CursorAdapter；
导入android.support.v4.widget.SimpleCursorAdapter；
导入android.app.ListActivity；
导入android.content.Intent；
导入android.database.Cursor；
导入android.view.Menu；
导入android.view.view；
导入android.widget.ArrayAdapter；
导入android.widget.ListView；
导入android.widget.Toast；
公共类MainActivity扩展了ListActivity{
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
游标c=getContentResolver（）.query（ContactsContract.Contacts.CONTENT\u URI，
无效的
无效的
无效的
Contacts contract.Contacts.DISPLAY_NAME+“ASC”）；
ArrayList con_id=新的ArrayList（）；
如果（c！=null）
{
for（c.moveToFirst（）；！c.isAfterLast（）；c.moveToNext（））{
con_ID.add（c.getString（c.getColumnIndex（ContactsContract.Contacts._ID））；
}
}
ListView ls=getListView（）；
MyAdapter ada=新的MyAdapter（this，R.layout.listview，con_id）；
ls.setAdapter（ada）；
}
@凌驾
公共布尔onCreateOptions菜单（菜单）{
//为菜单充气；这会将项目添加到操作栏（如果存在）。
getMenuInflater（）.充气（R.menu.activity\u主菜单）；
返回true；
}
}
下面是MyAdapter的代码

package legacy_systems.aggregatedcontactlist;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

import android.content.ContentUris;
import android.content.Context;
import android.content.pm.PackageManager.NameNotFoundException;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.provider.ContactsContract;
import android.provider.ContactsContract.Contacts;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;


public class MyAdapter extends ArrayAdapter<String>{
    Context cont;
    boolean image_found = true;
    ArrayList<String> ids;

    public MyAdapter(Context context, int resource,
            ArrayList<String> objects) {
        super(context, resource, objects);
        cont = context;
        ids = objects;
        // TODO Auto-generated constructor stub
    }

    public View getView(int position, View ConvertView, ViewGroup parent){
        //For Contact Photo
        Bitmap photo=null;
        //Inflator Work
        LayoutInflater infl = (LayoutInflater)cont.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View row = infl.inflate(R.layout.list_view, parent, false);

        //Retreiving photo and Setting Photo
        photo = BitmapFactory.decodeStream(retrievePhoto(ids.get(position)));
        ImageView iv = (ImageView)row.findViewById(R.id.listicon);
        iv.setImageBitmap(photo);

        if(!image_found)
        {
            iv.setImageResource(R.drawable.person);
        }

        //Retrieving ContactName
        TextView tv  =(TextView)row.findViewById(R.id.listtext);
        tv.setText(retrieveName(ids.get(position)));

        return row;
    }

    private InputStream retrievePhoto(String Id)
    {
        Uri ContactUri = ContentUris.withAppendedId(Contacts.CONTENT_URI, Long.valueOf(Id));
        Uri PhotoUri = Uri.withAppendedPath(ContactUri, Contacts.Photo.CONTENT_DIRECTORY);

        Cursor c = cont.getContentResolver().query(PhotoUri, new String[]{Contacts.Photo.PHOTO}, null,null,null);

        try
        {
            if(c.moveToFirst())
            {
                byte[] data = c.getBlob(0);
                if(data!=null)
                {
                    return new ByteArrayInputStream(data);
                }
                else
                {
                    image_found = false;
                }
            }
        }
        finally
        {
            c.close();
        }
        return null;
    }

    private String retrieveName(String Id)
    {
        Uri ContactUri = ContentUris.withAppendedId(Contacts.CONTENT_URI, Long.valueOf(Id));
        Cursor c = cont.getContentResolver()
                        .query(ContactUri, 
                                new String[]{ContactsContract.Contacts.DISPLAY_NAME}, 
                                null, 
                                null, 
                                null);
        if(c==null)
            return null;
        try
        {
            if(c.moveToFirst())
            {
                String name = c.getString(0);
                return name;
            }
        }
        finally
        {
            c.close();
        }
        return null;
    }

}

package legacy\u systems.aggregatedcontactlist；
导入java.io.ByteArrayInputStream；
导入java.io.InputStream；
导入java.util.ArrayList；
导入java.util.List；
导入android.content.ContentUris；
导入android.content.Context；
导入android.content.pm.PackageManager.NameNotFoundException；
导入android.database.Cursor；
导入android.graphics.Bitmap；
导入android.graphics.BitmapFactory；
导入android.net.Uri；
导入android.provider.contacts合同；
导入android.provider.Contacts contract.Contacts；
导入android.view.LayoutInflater；
导入android.view.view；
导入android.view.ViewGroup；
导入android.widget.ArrayAdapter；
导入android.widget.ImageView；
导入android.widget.TextView；
公共类MyAdapter扩展了ArrayAdapter{
语境控制；
布尔图像_found=true；
数组列表ID；
公共MyAdapter（上下文、int资源、，
ArrayList对象）{
超级（上下文、资源、对象）；
cont=上下文；
ids=对象；
//TODO自动生成的构造函数存根
}
公共视图getView（int位置、视图转换视图、视图组父视图）{
//联系照片
位图照片=空；
//充气机工作
LayoutInflater infl=（LayoutInflater）cont.getSystemService（Context.LAYOUT\u INFLATER\u SERVICE）；
视图行=内部充气（R.layout.list\u视图，父视图，false）；
//检索照片和设置照片
photo=BitmapFactory.decodeStream（retrievePhoto（id.get（position））；
ImageView iv=（ImageView）row.findViewById（R.id.listicon）；
iv.设置图像位图（照片）；
如果（！找到图像）
{
iv.setImageResource（R.drawable.person）；
}
//检索联系人姓名
TextView tv=（TextView）row.findViewById（R.id.listtext）；
tv.setText（retrieveName（id.get（position））；
返回行；
}
私有InputStream retrievePhoto（字符串Id）
{
Uri ContactUri=ContentUris.withAppendedId（Contacts.CONTENT_Uri，Long.valueOf（Id））；
Uri PhotoUri=Uri.withAppendedPath（ContactUri，Contacts.Photo.CONTENT\u目录）；
游标c=cont.getContentResolver（）.query（PhotoUri，新字符串[]{Contacts.Photo.Photo}，null，null，null）；
尝试
{
if（c.moveToFirst（））
{
字节[]数据=c.getBlob（0）；
如果（数据！=null）
{
返回新的ByteArrayInputStream（数据）；
}
其他的
{
图像_found=false；
}
}
}
最后
{
c、 close（）；
}
返回null；
}
私有字符串检索名称（字符串Id）
{
Uri ContactUri=ContentUris.withAppendedId（Contacts.CONTENT_Uri，Long.valueOf（Id））；
游标c=cont.getContentResolver（）
.query（ContactUri，
新字符串[]{Contacts contract.Contacts.DISPLAY_NAME}，
无效的
无效的
无效）；
如果（c==null）
返回null；
尝试
{
if（c.moveToFirst（））
{
String name=c.getString（0）；
返回名称；
}
}
最后
{
c、 close（）；
}
返回null；
}
}
我真的很高兴我走了这么远。请帮我继续我的冒险

[编辑] 我已落实建议的措施 
package legacy_systems.aggregatedcontactlist;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.List;

import android.content.ContentUris;
import android.content.Context;
import android.content.pm.PackageManager.NameNotFoundException;
import android.content.res.Resources;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.AsyncTask;
import android.provider.ContactsContract;
import android.provider.ContactsContract.Contacts;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;


public class MyAdapter extends ArrayAdapter<String>{
    Context cont;
    boolean image_found = true;
    ArrayList<String> ids;

    public MyAdapter(Context context, int resource,
            ArrayList<String> objects) {
        super(context, resource, objects);
        cont = context;
        ids = objects;
        // TODO Auto-generated constructor stub
    }

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

        View row = ConvertView;
        //For Contact Photo
        Bitmap photo=null;
        //Inflator Work
        if(row==null)
        {
            LayoutInflater infl = (LayoutInflater)cont.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            row = infl.inflate(R.layout.list_view, parent, false);
        }

        //Retreiving photo and Setting Photo
        ImageView iv = (ImageView)row.findViewById(R.id.listicon);


        synchronized (iv) {
            Uri contactUri = ContentUris.withAppendedId(Contacts.CONTENT_URI, Long.valueOf(ids.get(position)));
            PhotoLoader loader = new PhotoLoader(iv, contactUri);
            loader.execute();

        }



        //Retrieving ContactName
        TextView tv  =(TextView)row.findViewById(R.id.listtext);
        tv.setText(retrieveName(ids.get(position)));

        return row;
    }



    private String retrieveName(String Id)
    {
        Uri ContactUri = ContentUris.withAppendedId(Contacts.CONTENT_URI, Long.valueOf(Id));
        Cursor c = cont.getContentResolver()
                        .query(ContactUri, 
                                new String[]{ContactsContract.Contacts.DISPLAY_NAME}, 
                                null, 
                                null, 
                                null);
        if(c==null)
            return null;
        try
        {
            if(c.moveToFirst())
            {
                String name = c.getString(0);
                return name;
            }
        }
        finally
        {
            c.close();
        }
        return null;
    }

    class PhotoLoader extends AsyncTask<Void, Void, Bitmap>
    {
        final WeakReference<ImageView> mView;
        final Uri mUri;

        public PhotoLoader(ImageView view, Uri uri) {

            if(view == null)
            {
                throw new IllegalArgumentException("View Cannot be null");
            }
            if(uri == null)
            {
                throw new IllegalArgumentException("Uri cant be null");
            }
            mView = new WeakReference<ImageView>(view);
            mUri = uri;
        }

        protected Bitmap doInBackground(Void...args){
            Bitmap bitmap;
            InputStream in = ContactsContract.Contacts.openContactPhotoInputStream(cont.getContentResolver(), mUri);
            bitmap = BitmapFactory.decodeStream(in);

            if(bitmap == null)
            {   Resources mResources = cont.getResources();
                bitmap = BitmapFactory.decodeResource(mResources, R.drawable.person);
            }
            return bitmap;
        }
    }

}

package legacy_systems.aggregatedcontactlist;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.List;

import android.content.ContentUris;
import android.content.Context;
import android.content.pm.PackageManager.NameNotFoundException;
import android.content.res.Resources;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.AsyncTask;
import android.provider.ContactsContract;
import android.provider.ContactsContract.Contacts;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;


public class MyAdapter extends ArrayAdapter<String>{
    Context cont;
    boolean image_found = true;
    ArrayList<String> ids;
    ImageView iv;

    public MyAdapter(Context context, int resource,
            ArrayList<String> objects) {
        super(context, resource, objects);
        cont = context;
        ids = objects;
        // TODO Auto-generated constructor stub
    }

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

        View row = ConvertView;
        //For Contact Photo

        //Inflator Work

        if(row==null)
        {
            LayoutInflater infl = (LayoutInflater)cont.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            row = infl.inflate(R.layout.list_view, parent, false);
        }


        //Retreiving photo and Setting Photo
        iv = (ImageView)row.findViewById(R.id.listicon);


        synchronized (this) {
            Uri contactUri = ContentUris.withAppendedId(Contacts.CONTENT_URI, Long.valueOf(ids.get(position)));
            PhotoLoader loader = new PhotoLoader(iv, contactUri);
            loader.execute();

        }



        //Retrieving ContactName
        TextView tv  =(TextView)row.findViewById(R.id.listtext);
        tv.setText(retrieveName(ids.get(position)));

        return row;
    }



    private String retrieveName(String Id)
    {
        Uri ContactUri = ContentUris.withAppendedId(Contacts.CONTENT_URI, Long.valueOf(Id));
        Cursor c = cont.getContentResolver()
                        .query(ContactUri, 
                                new String[]{ContactsContract.Contacts.DISPLAY_NAME}, 
                                null, 
                                null, 
                                null);
        if(c==null)
            return null;
        try
        {
            if(c.moveToFirst())
            {
                String name = c.getString(0);
                return name;
            }
        }
        finally
        {
            c.close();
        }
        return null;
    }

    class PhotoLoader extends AsyncTask<Void, Void, Bitmap>
    {
        final WeakReference<ImageView> mView;
        final Uri mUri;

        public PhotoLoader(ImageView view, Uri uri) {

            if(view == null)
            {
                throw new IllegalArgumentException("View Cannot be null");
            }
            if(uri == null)
            {
                throw new IllegalArgumentException("Uri cant be null");
            }
            mView = new WeakReference<ImageView>(view);
            mUri = uri;
        }

        protected Bitmap doInBackground(Void...args){
            Bitmap bitmap;
            InputStream in = ContactsContract.Contacts.openContactPhotoInputStream(cont.getContentResolver(), mUri);
            bitmap = BitmapFactory.decodeStream(in);


            return bitmap;
        }

        protected void onPostExecute(Bitmap bitmap)
        {
            if(bitmap == null)
            {   Resources mResources = cont.getResources();
                bitmap = BitmapFactory.decodeResource(mResources, R.drawable.person);
                iv.setImageBitmap(bitmap);
                return;
            }
            iv.setImageBitmap(bitmap);
        }
    }

}

class PhotoLoader extends AsyncTask<Void, Void, Bitmap> {

    final WeakReference<ImageView> mView;
    final Uri mUri;

    PhotoLoader(ImageView view, Uri uri) {
        if (view == null) {
            throw new IllegalArgumentException("View cannot be null!");
        }

        if (uri == null) {
            throw new IllegalArgumentException("Uri cannot be null!");
        }

        mView = new WeakReference<ImageView>(view);
        mUri = uri;
    }

    @Override
    protected Bitmap doInBackground(Void... args) {
                    // use the uri passed to the constructor
        InputStream is = Contacts.openContactPhotoInputStream(mResolver,
                mUri);
        Bitmap bm = BitmapFactory.decodeStream(is);

                    // load custom resource image if contact has no photo
        if (bm == null) {
            bm = BitmapFactory.decodeResource(mResources,
                    R.drawable.ic_contact);
        }

        return bm;
    }

    @Override
    protected void onPostExecute(Bitmap result) {
                    // use a transition drawable for nice fade effect
        Drawable[] layers = new Drawable[2];
        layers[0] = mResources.getDrawable(android.R.color.transparent);

        layers[1] = new BitmapDrawable(mResources, result);
        TransitionDrawable t = new TransitionDrawable(layers);
        t.setCrossFadeEnabled(true);

        ImageView view = mView.get();

        if(view != null) {
            view.setImageDrawable(t);
            t.startTransition(mShortAnimation);
        }
        synchronized (mPhotoCache) {
                            // store bitmap in LruCache for later use...
            mPhotoCache.put(mUri.toString(), result);
        }
    }
}

synchronized (mPhotoCache) {
    Bitmap b = mPhotoCache.get(key);

    if (b != null) {
    imageView.setImageBitmap(b);
    } else {
    imageView.setImageResource(android.R.color.transparent);
    PhotoLoader loader = new PhotoLoader(imageView, uri);
    loader.execute();
    }
}

package com.example.contact;

import java.io.InputStream;
import java.util.ArrayList;



import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.os.AsyncTask;
import android.provider.ContactsContract;
import android.provider.ContactsContract.Contacts;
import android.support.v4.util.LruCache;
import android.support.v4.widget.SimpleCursorAdapter;
import android.view.View;
import android.widget.ImageView;

public class MyAdapter extends SimpleCursorAdapter{

    private Cursor cursor;  
    private static int con_id_index;
    private static Drawable person;
    private Context context;
    private static LruCache<Long, Bitmap> cache;
    long con_id;
    private ArrayList<Long> id_list = new ArrayList<Long>();

    public MyAdapter(Context context, int layout, Cursor c, String[] from,
            int[] to, int flags) {
        super(context, layout, c, from, to, flags);
        this.cursor = c;        
        con_id_index = cursor.getColumnIndex(ContactsContract.Contacts._ID);
        person = context.getResources().getDrawable(R.drawable.person);
        this.context = context;

        final int maxMem = (int)Runtime.getRuntime().maxMemory()/1024;
        final int cacheSize = maxMem/8;

        cache = new LruCache<Long, Bitmap>(cacheSize);
        id_list.clear();
    }   


    @Override
    public void bindView(View view, Context context, Cursor cursor) {
        Object tag;
        // TODO Auto-generated method stub
        super.bindView(view, context, cursor);

        con_id = cursor.getLong(con_id_index);
        if(!id_list.contains(Long.valueOf(con_id)))
        {
            id_list.add(con_id);
        }
        Uri contactUri = ContentUris.withAppendedId(Contacts.CONTENT_URI, con_id);

        ImageView con_image = (ImageView) view.findViewById(R.id.contact_iamge);
        tag = con_id;
        con_image.setImageDrawable(person);
        con_image.setTag(tag);
        if(getBitmapFromCache(con_id)!=null)
        {
            con_image.setImageBitmap(getBitmapFromCache(con_id));
        }
        else
        {
            ImageLoader loader = new ImageLoader(con_image, contactUri, con_id);
            loader.execute();
        }

    }

    class ImageLoader extends AsyncTask<Void, Void, Bitmap>
    {
        private ImageView mView;
        private Uri mUri;       
        private Object tag;
        private long position;

        public ImageLoader(ImageView view, Uri uri, long position) {

            if(view == null)
            {
                throw new IllegalArgumentException("View Cannot be null");
            }
            if(uri == null)
            {
                throw new IllegalArgumentException("Uri cant be null");
            }
            mView = view;
            tag = mView.getTag();
            this.position = position;
            mUri = uri;         
        }

        protected Bitmap doInBackground(Void...args){
            Bitmap bitmap;

            //Load image from the Content Provider
            InputStream in = ContactsContract.Contacts.openContactPhotoInputStream(context.getContentResolver(), mUri);
            bitmap = BitmapFactory.decodeStream(in);

            return bitmap;
        }

        protected void onPostExecute(Bitmap bitmap)
        {
            //If is in somewhere else, do not temper
            if(!mView.getTag().equals(tag))
                return;
            //If no image was there and do not put it to cache
            if(bitmap!= null)
            {   

                mView.setImageBitmap(bitmap);
                addBitmapToCache(position, bitmap);
                return;
            }
            //Otherwise, welcome to cache           
            return;
        }
    }
    /**Add image to cache*/
    private void addBitmapToCache(Long key, Bitmap bitmap)
    {
        if(getBitmapFromCache(key)==null)
        {
            cache.put(key, bitmap);
        }
    }
    /**Retrive image from cache*/
    private Bitmap getBitmapFromCache(Long key)
    {
        return cache.get(key);
    }

    public ArrayList<Long> getIDList()
    {
        return id_list;
    }

}