我正在显示联系人列表。除了该设备有 1620 个联系人之外，一切都很好，因此列表滚动非常缓慢，甚至有时会挂起。
I tried using a check in getView method for ConvertView!=null but it alwayz inflate same view many times. thanks in advance..
My code for getView method:-
if(ConvertView==null)
{ view= mInflater.inflate(R.layout.facebookfriend, null);
TextView name=(TextView)view.findViewById(R.id.textView1);
ImageView image=(ImageView)view.findViewById(R.id.imageView1);
name.setText(mlist.get(position).get("name"));
String Id=mlist.get(position).get("contactId");
Log.e("Id",""+Id);
CheckBox chkbox= (CheckBox)view.findViewById(R.id.checkBox1);
chkbox.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(
CompoundButton buttonView, boolean isChecked) {
isSelected.set(position, isChecked);
}
});
String photoid=mlist.get(position).get("photoId");
Log.e("photoid",""+photoid);
if(mlist.get(position).get("photoId")!=null){
Log.e("photoid",""+"photoid");
image.setImageBitmap(loadContactPhoto(Id, mlist.get(position).get("photoId")));
}
}
}
有人告诉我让列表视图根据要求动态加载数据，也可以使用 ViewHolder 来提高效率。我已经尝试过使用视图支架，但每次它都会一次又一次地膨胀单个视图。我的列表滚动非常顺利，但真的不知道为什么它一次又一次地膨胀同一个视图。请帮忙 。我的 viewHolder 代码：-
if (ConvertView == null) {
holder = new ViewHolder();
ConvertView= mInflater.inflate(R.layout.facebookfriend, null);
holder.name = (TextView)ConvertView.findViewById(R.id.textView1);
holder.imageView = (ImageView)ConvertView.findViewById(R.id.imageView1);
holder.chkbox= (CheckBox)ConvertView.findViewById(R.id.checkBox1);
ConvertView.setTag(holder);
} else {
holder = (ViewHolder) ConvertView.getTag();
}
holder.name.setText(mlist.get(position).get("Name").toString());
holder. chkbox.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(
CompoundButton buttonView, boolean isChecked) {
isSelected.set(position, isChecked);
Log.e("position"+position,""+isChecked);
}
});
String Id=mlist.get(position).get("Contactid").toString();
Log.e("Id","--------------"+Id);
if(mlist.get(position).get("Photoid")!=null){
Log.e("photoid",""+"photoid");
holder.imageView.setImageBitmap(loadContactPhoto(Id, mlist.get(position).get("Photoid")));
Log.e("position position",""+position);
}
}
static class ViewHolder {
TextView name;
ImageView imageView;
CheckBox chkbox;
}
我的 Imagefrom 联系方式的代码，我非常确定这个代码
private Bitmap loadContactPhoto(String id, String photoId) {
Long _id=Long.parseLong(id);
Long _photoId=0l;
if(photoId!=null){
_photoId=Long.parseLong(photoId);
}
ContentResolver cr = Setting.this.getContentResolver();
Uri uri = ContentUris.withAppendedId(ContactsContract.Contacts.CONTENT_URI, _id);
InputStream input = ContactsContract.Contacts.openContactPhotoInputStream(cr, uri);
if (input != null) {
return BitmapFactory.decodeStream(input);
} else {
Log.d("PHOTO", "first try failed to load photo");
}
byte[] photoBytes = null;
Uri photoUri = ContentUris.withAppendedId(ContactsContract.Data.CONTENT_URI, _photoId);
Cursor c = cr.query(photoUri,new String[] { ContactsContract.CommonDataKinds.Photo.PHOTO },
null, null, null);
try {
if (c.moveToFirst())
photoBytes = c.getBlob(0);
} catch (Exception e) {
e.printStackTrace();
} finally {
c.close();
}
if (photoBytes != null)
return BitmapFactory.decodeByteArray(photoBytes, 0,
photoBytes.length);
else
Log.d("PHOTO", "second try also failed");
Bitmap icon = BitmapFactory.decodeResource(this.getResources(),
R.drawable.default_image);
return icon;
}