Android 图像缩略图设置不正确
我正在尝试制作一个文件浏览器。我实现了这一切,只是我的图像缩略图加载太慢了。所以我读到我必须移动到asynctask,然后在执行后更新ui。在运行asynctask之前,我为所有文件提供默认缩略图。在asynctask中,我将位置作为参数,因为我使用它们设置标记。然后我用那个位置检查文件。如果是图像或视频,我会为它创建一个位图。在post-execute中,我创建了一个新的viewholder,并使用getTag(position)为其分配相同的标记。然后我使用setBitmapImage分配位图。问题:即使文件不是图像/视频,缩略图也在更改/闪烁。 到目前为止我已经尝试过的事情: a)Android 图像缩略图设置不正确,android,image,listview,android-asynctask,Android,Image,Listview,Android Asynctask,我正在尝试制作一个文件浏览器。我实现了这一切,只是我的图像缩略图加载太慢了。所以我读到我必须移动到asynctask,然后在执行后更新ui。在运行asynctask之前,我为所有文件提供默认缩略图。在asynctask中,我将位置作为参数,因为我使用它们设置标记。然后我用那个位置检查文件。如果是图像或视频,我会为它创建一个位图。在post-execute中,我创建了一个新的viewholder,并使用getTag(position)为其分配相同的标记。然后我使用setBitmapImage分配位
(b) 以下是我的getView代码:
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
File file=new File(String.valueOf(filenames[position]));
if(file.isDirectory()){
img=R.drawable.folder;
}
else{
img=getImage(filenames[position]);
}
ViewHolder viewHolder = null;
if (convertView == null) {
LayoutInflater inflator = LayoutInflater.from(getContext());
convertView = inflator.inflate(R.layout.list_item, null);
viewHolder = new ViewHolder();
viewHolder.tv = (TextView) convertView.findViewById(R.id.textView1);
viewHolder.cb = (CheckBox) convertView.findViewById(R.id.checkBox1);
viewHolder.iv= (ImageView)convertView.findViewById(R.id.imageView);
viewHolder.cb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
int getPosition = (Integer) buttonView.getTag(); // Here we get the position that we have set for the checkbox using setTag.
myList.get(getPosition).setSelected(buttonView.isChecked()); // Set the value of checkbox to maintain its state.
}
});
convertView.setTag(viewHolder);
convertView.setTag(R.id.textView1, viewHolder.tv);
convertView.setTag(R.id.checkBox1, viewHolder.cb);
convertView.setTag(R.id.checkBox1, viewHolder.iv);
}
else {
viewHolder = (ViewHolder) convertView.getTag();
}
viewHolder.iv.getLayoutParams().height = 80;
viewHolder.iv.getLayoutParams().width = 80;
viewHolder.cb.setTag(position);
final ViewHolder ViewHolder= viewHolder;
ViewHolder.iv.setImageResource(img);
ViewHolder.tv.setText(myList.get(position).getName());
ViewHolder.cb.setChecked(myList.get(position).isSelected());
final View finalConvertView = convertView;
class myTask extends AsyncTask<Integer,Void,Bitmap>{
int pos;
public myTask(int pos){
this.pos=pos;
}
@Override
protected Bitmap doInBackground(Integer... params) {
Bitmap thumb=null;
if((String.valueOf(filenames[pos])).contains(".jpeg")||String.valueOf(filenames[pos]).contains(".jpg")||String.valueOf(filenames[pos]).contains(".png")||String.valueOf(filenames[pos]).contains(".bmp")||String.valueOf(filenames[pos]).contains(".webp")||String.valueOf(filenames[pos]).contains(".gif")){
thumb = ThumbnailUtils.extractThumbnail(BitmapFactory.decodeFile(String.valueOf(filenames[pos])), 64, 64);
}
else if((String.valueOf(filenames[pos])).contains(".mp4")||String.valueOf(filenames[pos]).contains(".mkv")||String.valueOf(filenames[pos]).contains(".webm")||String.valueOf(filenames[pos]).contains(".3gp")||String.valueOf(filenames[pos]).contains(".3gpp")){
thumb=ThumbnailUtils.createVideoThumbnail(filenames[pos].getPath(), MediaStore.Video.Thumbnails.MINI_KIND);
}
return thumb;
}
@Override
protected void onPostExecute(Bitmap thumb){
if(isCancelled()){
return;
}
ViewHolder v= (ViewHolder) finalConvertView.getTag(pos);
if((String.valueOf(filenames[pos])).contains(".jpeg")||String.valueOf(filenames[pos]).contains(".jpg")||String.valueOf(filenames[pos]).contains(".png")||String.valueOf(filenames[pos]).contains(".bmp")||String.valueOf(filenames[pos]).contains(".webp")||String.valueOf(filenames[pos]).contains(".gif")){
v.iv.setImageBitmap(thumb);
}
else if((String.valueOf(filenames[pos])).contains(".mp4")||String.valueOf(filenames[pos]).contains(".mkv")||String.valueOf(filenames[pos]).contains(".webm")||String.valueOf(filenames[pos]).contains(".3gp")||String.valueOf(filenames[pos]).contains(".3gpp")){
v.iv.setImageBitmap(thumb);
}
}
}
myTask m=new myTask(position);
m.execute();
return convertView;
}
@覆盖
公共视图getView(最终整数位置、视图转换视图、视图组父视图){
File File=新文件(String.valueOf(filenames[position]);
if(file.isDirectory()){
img=R.drawable.folder;
}
否则{
img=getImage(文件名[位置]);
}
ViewHolder ViewHolder=null;
if(convertView==null){
LayoutInflater充气器=LayoutInflater.from(getContext());
convertView=充气机充气(R.layout.list_项,空);
viewHolder=新的viewHolder();
viewHolder.tv=(TextView)convertView.findViewById(R.id.textView1);
viewHolder.cb=(复选框)convertView.findViewById(R.id.checkBox1);
viewHolder.iv=(ImageView)convertView.findViewById(R.id.ImageView);
viewHolder.cb.setOnCheckedChangeListener(新的CompoundButton.OnCheckedChangeListener(){
@凌驾
检查更改后的公共无效(复合按钮视图,布尔值已检查){
int getPosition=(Integer)buttonView.getTag();//这里我们使用setTag获取为复选框设置的位置。
myList.get(getPosition).setSelected(buttonView.isChecked());//设置复选框的值以保持其状态。
}
});
convertView.setTag(viewHolder);
setTag(R.id.textView1,viewHolder.tv);
setTag(R.id.checkBox1,viewHolder.cb);
convertView.setTag(R.id.checkBox1,viewHolder.iv);
}
否则{
viewHolder=(viewHolder)convertView.getTag();
}
viewHolder.iv.getLayoutParams().height=80;
viewHolder.iv.getLayoutParams().width=80;
viewHolder.cb.setTag(位置);
最终视窗持有人视窗持有人=视窗持有人;
ViewHolder.iv.setImageResource(img);
ViewHolder.tv.setText(myList.get(position.getName());
ViewHolder.cb.setChecked(myList.get(position.isSelected());
最终视图finalConvertView=convertView;
类myTask扩展了AsyncTask{
int pos;
公共myTask(int pos){
这个.pos=pos;
}
@凌驾
受保护位图doInBackground(整数…参数){
位图拇指=空;
if((.jpg)valueOf(filenames[pos])包含(“.jpeg”)|| String.valueOf(filenames[pos])包含(“.jpg”)|| String.valueOf(filenames[pos])包含(“.bmp”)| String.valueOf(filenames[pos])包含(“.webp”)| String.valueOf(filenames[pos包含(“.gif”)){
thumb=ThumbnailUtils.extractThumbnail(BitmapFactory.decodeFile(String.valueOf(filenames[pos])),64,64;
}
else if((String.valueOf(filenames[pos])包含(“.mp4”)| | String.valueOf(filenames[pos])包含(“.mkv”)| | String.valueOf(filenames[pos])包含(“.3gp”)| String.valueOf(filenames[pos包含(“.3gpp”)){
thumb=ThumbnailUtils.createVideoThumbnail(文件名[pos].getPath(),MediaStore.Video.Thumbnails.MINI_-KIND);
}
回拇指;
}
@凌驾
受保护的void onPostExecute(位图拇指){
如果(isCancelled()){
返回;
}
ViewHolder v=(ViewHolder)finalConvertView.getTag(pos);
if((.jpg)valueOf(filenames[pos])包含(“.jpeg”)|| String.valueOf(filenames[pos])包含(“.jpg”)|| String.valueOf(filenames[pos])包含(“.bmp”)| String.valueOf(filenames[pos])包含(“.webp”)| String.valueOf(filenames[pos包含(“.gif”)){
v、 iv.设置图像位图(拇指);
}
else if((String.valueOf(filenames[pos])包含(“.mp4”)| | String.valueOf(filenames[pos])包含(“.mkv”)| | String.valueOf(filenames[pos])包含(“.3gp”)| String.valueOf(filenames[pos包含(“.3gpp”)){
v、 iv.设置图像位图(拇指);
}
}
}
myTask m=新的myTask(职位);
m、 执行();
返回视图;
}
我终于找到了答案
以下是ListAdapter类:
class ListAdapter extends ArrayAdapter<Modal> {
private final Context context;
private int img;
private List<Modal> myList;
private File filenames[];
private List<Integer> selectedItems=new ArrayList<Integer>();
private CheckBox cb;
public ListAdapter(Context context, List<Modal> list, File filenames[]) {
super(context, R.layout.list_item, list);
this.context = context;
this.myList = list;
this.filenames=filenames;
}
@Override
public int getViewTypeCount() {
if(getCount()>0){
return getCount();
}
return 1;
}
@Override
public int getItemViewType(int position) {
return position;
}
@Override
public long getItemId(int position) {
return position;
}
static class ViewHolder {
TextView tv;
CheckBox cb;
static ImageView iv;
}
public int getImage(File filename){
if(String.valueOf(filename).contains(".rar")||String.valueOf(filename).contains(".zip")){
return R.drawable.archive;
}
else if(String.valueOf(filename).contains(".doc")||String.valueOf(filename).contains(".docx")){
return R.drawable.doc;
}
else if(String.valueOf(filename).contains(".pdf")){
return R.drawable.pdf;
}
else if(String.valueOf(filename).contains(".txt")){
return R.drawable.txt;
}
else if(String.valueOf(filename).contains(".ppt")||String.valueOf(filename).contains(".pptx")){
return R.drawable.ppt;
}
else if(String.valueOf(filename).contains(".xls")||String.valueOf(filename).contains(".xlsx")){
return R.drawable.xls;
}
else if((String.valueOf(filename).contains(".jpeg")||String.valueOf(filename).contains(".jpg")||String.valueOf(filename).contains(".png")||String.valueOf(filename).contains(".bmp")||String.valueOf(filename).contains(".webp")||String.valueOf(filename).contains(".gif"))){
return R.drawable.image;
}
else if((String.valueOf(filename).contains(".mp4")||String.valueOf(filename).contains(".mkv")||String.valueOf(filename).contains(".webm")||String.valueOf(filename).contains(".3gp")||String.valueOf(filename).contains(".3gpp"))||String.valueOf(filename).contains(".MOV")){
return R.drawable.video;
}
else if((String.valueOf(filename).contains(".mp3")||String.valueOf(filename).contains(".wav")||String.valueOf(filename).contains(".wma")||String.valueOf(filename).contains(".MP2")||String.valueOf(filename).contains(".AAC")||String.valueOf(filename).contains(".AC3")||String.valueOf(filename).contains(".AU")||String.valueOf(filename).contains(".OGG")||String.valueOf(filename).contains(".FLAC"))){
return R.drawable.music;
}
else {
return R.drawable.unknown;
}
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
File file=new File(String.valueOf(filenames[position]));
if(file.isDirectory()){
img=R.drawable.folder;
}
else{
img=getImage(filenames[position]);
}
ViewHolder viewHolder = null;
if (convertView == null) {
LayoutInflater inflator = LayoutInflater.from(getContext());
convertView = inflator.inflate(R.layout.list_item, null);
viewHolder = new ViewHolder();
viewHolder.tv = (TextView) convertView.findViewById(R.id.textView1);
viewHolder.cb = (CheckBox) convertView.findViewById(R.id.checkBox1);
viewHolder.iv= (ImageView)convertView.findViewById(imageView);
viewHolder.cb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
int getPosition = (Integer) buttonView.getTag(); // Here we get the position that we have set for the checkbox using setTag.
myList.get(getPosition).setSelected(buttonView.isChecked()); // Set the value of checkbox to maintain its state.
}
});
convertView.setTag(viewHolder);
convertView.setTag(R.id.textView1, viewHolder.tv);
convertView.setTag(R.id.checkBox1, viewHolder.cb);
convertView.setTag(R.id.checkBox1, viewHolder.iv);
}
else {
viewHolder = (ViewHolder) convertView.getTag();
}
viewHolder.iv.getLayoutParams().height = 150;
viewHolder.iv.getLayoutParams().width = 150;
viewHolder.cb.setTag(position);
final ViewHolder ViewHolder= viewHolder;
ViewHolder.tv.setText(myList.get(position).getName());
ViewHolder.cb.setChecked(myList.get(position).isSelected());
viewHolder.iv.setImageResource(img);
Log.v("this","viewHolderMT: "+String.valueOf(viewHolder)+" position: "+position);
myTask m=new myTask(position,viewHolder.iv);
m.execute();
return convertView;
}
class myTask extends AsyncTask<Integer,Bitmap,Bitmap>{
int pos;
ImageView iv;
public myTask(int pos,ImageView iv){
this.pos=pos;
this.iv=iv;
iv.setTag(pos);
}
@Override
protected Bitmap doInBackground(Integer... params) {
Bitmap thumb=null;
if((String.valueOf(filenames[pos])).contains(".jpeg")||String.valueOf(filenames[pos]).contains(".jpg")||String.valueOf(filenames[pos]).contains(".png")||String.valueOf(filenames[pos]).contains(".bmp")||String.valueOf(filenames[pos]).contains(".webp")||String.valueOf(filenames[pos]).contains(".gif")){
thumb = ThumbnailUtils.extractThumbnail(BitmapFactory.decodeFile(String.valueOf(filenames[pos])), 150, 150);
}
else if((String.valueOf(filenames[pos])).contains(".mp4")||String.valueOf(filenames[pos]).contains(".mkv")||String.valueOf(filenames[pos]).contains(".webm")||String.valueOf(filenames[pos]).contains(".3gp")||String.valueOf(filenames[pos]).contains(".3gpp")||String.valueOf(filenames[pos]).contains(".MOV")){
thumb=ThumbnailUtils.createVideoThumbnail(filenames[pos].getPath(), MediaStore.Video.Thumbnails.MINI_KIND);
}
return thumb;
}
@Override
protected void onProgressUpdate(Bitmap... thumb){
}
@Override
protected void onPostExecute(Bitmap thumb){
if(thumb!=null && (Integer)iv.getTag()==this.pos) {
if ((String.valueOf(filenames[pos])).contains(".jpeg") || String.valueOf(filenames[pos]).contains(".jpg") || String.valueOf(filenames[pos]).contains(".png") || String.valueOf(filenames[pos]).contains(".bmp") || String.valueOf(filenames[pos]).contains(".webp") || String.valueOf(filenames[pos]).contains(".gif")) {
iv.setImageBitmap(thumb);
}
else if ((String.valueOf(filenames[pos])).contains(".mp4") ||String.valueOf(filenames[pos]).contains(".MOV")|| String.valueOf(filenames[pos]).contains(".mkv") || String.valueOf(filenames[pos]).contains(".webm") || String.valueOf(filenames[pos]).contains(".3gp") || String.valueOf(filenames[pos]).contains(".3gpp")) {
iv.setImageBitmap(thumb);
}
}
}
}
}
class ListAdapter扩展了ArrayAdapter{
私人最终语境;
私人互联网;
私人名单;
私有文件名[];
private List selectedItems=new ArrayList();
私家车;
公共ListAdapter(上下文上下文、列表、文件名[]){
super(上下文、R.layout.list\u项、列表);
this.context=上下文;
this.myList=list;
this.filenames=文件名;
}
@凌驾
public int getViewTypeCount(){
如果(getCount()>0){
返回getCount();
}
返回1;
}
@凌驾
public int getItemViewType(int位置){
返回位置;
}
@凌驾
公共长getItemId(int位置){
返回位置;
}
静态类视窗夹{
文本视图电视;
复选框cb;
静态图像视图iv;
}
public int getImage(文件名){
if(String.valueOf(filename).contains(“.rar”)| | String.valueOf(filename).contains(“.zip”)){
返回R.drawable.archive;
}