从加载图像资产为GridView控件使用平滑滚动 [英] Loading Images from assets to GridView with smooth Scrolling
问题描述
我试图加载从资产文件夹 GridView控件
图像与不光滑以下适配器不过gridview的滚动。有人建议我怎么能提高我的这个code?
还有一件事我收到某些设备上由于这种内存错误。如何优化这一方案?
公共类GridViewAdapter延伸BaseAdapter { 上下文mContext; 公共GridViewAdapter(上下文mContext){
this.mContext = mContext;
} @覆盖
公共查看getView(INT位置,查看convertView,父母的ViewGroup){
持有人持有人;
如果(convertView == NULL){
持有人=新的持有人();
LayoutInflater inflater1 =(LayoutInflater)this.mContext
.getSystemService(Context.LAYOUT_INFLATER_SERVICE); convertView = inflater1.inflate(R.layout.gv_item,NULL);
holder.imageView =(GridImageView)convertView.findViewById(R.id.imageView);
convertView.setTag(保持器);
}其他{
支架=(座)convertView.getTag();
}
holder.imageView.setImageBitmap(Helper.getBitmapFromAssets((位置+ 1)+_ THUM,mContext));
返回convertView;
} 私有静态类持有人{
GridImageView ImageView的;
}
@覆盖
公众诠释的getCount(){
返回Constants.TOTAL_IMAGES;
} @覆盖
公共对象的getItem(INT位置){
返回的位置;
} @覆盖
众长getItemId(INT位置){
返回0;
}
}
和我的 Helper.getBitmapFromAssets
跟随。
/ **
*从资产文件夹的图像
* @参数文件名
* @返回
* /
公共静态位图getBitmapFromAssets(字符串FILEID,上下文mContext){
AssetManager assetManager = mContext.getAssets(); InputStream的ISTR;
位图位图= NULL;
尝试{
ISTR = assetManager.open(图像/+ FILEID +加密。);
位= BitmapFactory.de codeStream(ISTR);
}赶上(IOException异常五){
// TODO自动生成catch块
e.printStackTrace();
} 返回位图;
}
- 创建ArrayList中包含的资产图像的路径(例如
文件夹名称/ 1.png)
AssetManager assetManager = getResources()getAssets();
ArrayList的listpath;
{尝试 的String []文件= assetManager.list(文件夹名);
listpath ==新的ArrayList<串GT; ();
对于(字符串strImageName:文件){
pathAssets =文件夹名+文件分割符+ strImageName;
listpath.add(pathAssets); }
- 电话适配器
{尝试
如果(listBitmap!= NULL){
ADP =新GridViewAdapter(这一点,R.layout.grid_item,listBitmap);
gridView.setAdapter(ADP);
}
}赶上(例外五){
e.printStackTrace();
}
适配器code(使用UniversalImageLoder载入图像)
从这里 下载jar文件
进口的java.io.File;
进口的java.util.ArrayList; 进口android.app.Service;
进口android.content.Context;
进口android.view.LayoutInflater;
进口android.view.View;
进口android.view.ViewGroup;
进口android.widget.BaseAdapter;
进口android.widget.ImageView;
进口android.widget.TextView; 进口com.nostra13.universalimageloader.core.DisplayImageOptions;
进口com.nostra13.universalimageloader.core.ImageLoader;
进口com.nostra13.universalimageloader.core.ImageLoaderConfiguration; 公共类GridViewAdapter延伸BaseAdapter {
上下文语境;
INT layoutResourceId;
私人的ArrayList<串GT; griRowItems;
LayoutInflater六;
ImageLoader的ImageLoader的;
的String [] imageUrls;
ArrayList的<串GT;的ImagePath;
DisplayImageOptions选择;
ViewHolder支架=无效; 公共GridViewAdapter(上下文的背景下,
INT layoutResourceId,ArrayList的<串GT; MAPPS){
this.context =背景;
this.griRowItems = MAPPS;
this.layoutResourceId = layoutResourceId;
VI =(LayoutInflater)上下文
.getSystemService(Service.LAYOUT_INFLATER_SERVICE); ImageLoader的= ImageLoader.getInstance();
this.imageLoader.init(ImageLoaderConfiguration.createDefault(上下文)); } @覆盖
公共查看getView(INT位置,查看convertView,父母的ViewGroup){ 如果(convertView == NULL){
convertView = vi.inflate(R.layout.grid_item,父母,
假);
持有人=新ViewHolder();
} holder.imageView =(ImageView的)convertView.findViewById(R.id.ivImage);
// holder.progressBar =(进度)convertView
// .findViewById(R.id.progress); 字符串tempStr =资产://+ griRowItems.get(位置);
惰性加载(ImageLoader的,tempStr,holder.imageView,
选项);
返回convertView;
}
@覆盖
公众诠释的getCount(){
返回griRowItems.size();
} @覆盖
公共对象的getItem(INT位置){
返回griRowItems.get(位置);
} @覆盖
众长getItemId(INT位置){
返回的位置;
} 静态类ViewHolder {
ImageView的ImageView的;
//进度进度;
TextView的tvTitle;
// DisplayImageOptions选择;
}
}
把这个方法内部适配器,用于加载图像流畅
公共静态无效的惰性加载(ImageLoader的ImageLoader的,字符串tempStr,ImageView的ImageView的,DisplayImageOptions选项){
imageLoader.displayImage(tempStr,ImageView的,期权,
新SimpleImageLoadingListener(){
@覆盖
公共无效onLoadingStarted(字符串imageUri,查看视图){
} @覆盖
公共无效onLoadingFailed(字符串imageUri,观景,FailReason failReason){
} @覆盖
公共无效onLoadingComplete(字符串imageUri,观景,位图loadedImage){
}
},新ImageLoadingProgressListener(){
@覆盖
公共无效onProgressUpdate(字符串imageUri,观景,INT当前,诠释总计){
}
});
}
I am trying to load images in GridView
from assets folder with following adapter however gridview scrolling in not smooth. Can someone suggest how can I improve my this code?
And one more thing I am getting memory errors on some devices due to this. How can I optimize this program?
public class GridViewAdapter extends BaseAdapter {
Context mContext;
public GridViewAdapter(Context mContext){
this.mContext = mContext;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
Holder holder;
if (convertView == null) {
holder = new Holder();
LayoutInflater inflater1 = (LayoutInflater) this.mContext
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater1.inflate(R.layout.gv_item, null);
holder.imageView = (GridImageView) convertView.findViewById(R.id.imageView);
convertView.setTag(holder);
} else {
holder = (Holder) convertView.getTag();
}
holder.imageView.setImageBitmap(Helper.getBitmapFromAssets((position+1)+"_thum", mContext));
return convertView;
}
private static class Holder {
GridImageView imageView;
}
@Override
public int getCount() {
return Constants.TOTAL_IMAGES;
}
@Override
public Object getItem(int position) {
return position;
}
@Override
public long getItemId(int position) {
return 0;
}
}
And my Helper.getBitmapFromAssets
is following.
/**
* Reads Images from Assets Folder
* @param fileName
* @return
*/
public static Bitmap getBitmapFromAssets(String fileID, Context mContext) {
AssetManager assetManager = mContext.getAssets();
InputStream istr;
Bitmap bitmap = null;
try {
istr = assetManager.open("images/"+fileID+".encrypted");
bitmap = BitmapFactory.decodeStream(istr);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return bitmap;
}
- Create ArrayList contain path of asset images (e.g FolderName/1.png)
AssetManager assetManager = getResources().getAssets();
ArrayList listpath;
try {
String[] files = assetManager.list("foldername");
listpath==new ArrayList<String> ();
for (String strImageName : files) {
pathAssets = "foldername" + File.separator+ strImageName;
listpath.add(pathAssets );
}
- Call Adapter
try {
if (listBitmap!= null) {
adp = new GridViewAdapter(this,R.layout.grid_item,listBitmap);
gridView.setAdapter(adp);
}
} catch (Exception e) {
e.printStackTrace();
}
Adapter code (Load Images using UniversalImageLoder ) Download jar file from here
import java.io.File;
import java.util.ArrayList;
import android.app.Service;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
public class GridViewAdapter extends BaseAdapter {
Context context;
int layoutResourceId;
private ArrayList<String> griRowItems;
LayoutInflater vi;
ImageLoader imageLoader;
String[] imageUrls;
ArrayList<String> imagePath;
DisplayImageOptions options;
ViewHolder holder = null;
public GridViewAdapter(Context context,
int layoutResourceId, ArrayList<String> mApps) {
this.context = context;
this.griRowItems = mApps;
this.layoutResourceId = layoutResourceId;
vi = (LayoutInflater) context
.getSystemService(Service.LAYOUT_INFLATER_SERVICE);
imageLoader = ImageLoader.getInstance();
this.imageLoader.init(ImageLoaderConfiguration.createDefault(context));
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView == null) {
convertView = vi.inflate(R.layout.grid_item, parent,
false);
holder = new ViewHolder();
}
holder.imageView = (ImageView) convertView.findViewById(R.id.ivImage);
// holder.progressBar = (ProgressBar) convertView
// .findViewById(R.id.progress);
String tempStr = "assets://" + griRowItems.get(position);
lazyLoading(imageLoader, tempStr, holder.imageView,
options);
return convertView;
}
@Override
public int getCount() {
return griRowItems.size();
}
@Override
public Object getItem(int position) {
return griRowItems.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
static class ViewHolder {
ImageView imageView;
// ProgressBar progressBar;
TextView tvTitle;
// DisplayImageOptions options;
}
}
put this method inside adapter for load images smoothly
public static void lazyLoading(ImageLoader imageLoader, String tempStr, ImageView imageView,DisplayImageOptions options) {
imageLoader.displayImage(tempStr, imageView, options,
new SimpleImageLoadingListener() {
@Override
public void onLoadingStarted(String imageUri, View view) {
}
@Override
public void onLoadingFailed(String imageUri, View view,FailReason failReason) {
}
@Override
public void onLoadingComplete(String imageUri, View view,Bitmap loadedImage) {
}
}, new ImageLoadingProgressListener() {
@Override
public void onProgressUpdate(String imageUri, View view,int current, int total) {
}
});
}
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