I am using a GridView having image as child items.
The getView functions loads a default image from the application "Loading.gif" for all the child items.
In another thread I load all the images to some Bitmap type into the adapter.
Is it wise enough to call adapter.notifyDataSetChanged() after each image is loaded ?
Or is there and alternative way to directly update the image ?
Checkout the technique used in ListView , where default image used in listview items. And a thread load images for list items and update the new images without adapter.notifyDataSetChanged() called.
http://iamvijayakumar.blogspot.com/2011/06/android-lazy-image-loader-example.html
If you want more efficient way to do this then check this out.
http://developer.android.com/resources/samples/XmlAdapters/src/com/example/android/xmladapters/ImageDownloader.html
Related
I have a bunch of local images named image01.png ... image30.png. I want to display those images using recylceview (for better memory handling) in a fragment. I would like to use Picasso to load and resize those image.
All solutions I found is using an adapter. Can anybody suggest any easier way to impalement this without using adapter? Thanks lot in advance.
I'm guessing you want to use caching capability of Picasso to efficiently load your images.
If that is the case then why don't you use an adapter with Recycler View. Provide adapter only the name of of the images and finally inside the adapter use Picasso to load the images.
Any ViewGroup that dynamically populates its children with data from a data source like an ArrayList or a database does so using an adapter. A RecyclerView (or a ListView, GridView, ViewPager, etc.) cannot function without an adapter. If you do not want to use an adapter, use a LinearLayout inside a ScrollView.
I am working on a android project and i am implementing an adapter for my listview.
My adapter simply load an image and a text together and show them on the listview
but it's not efficient to load all image on cach.
So i'm looking for a way just to load image which are shown to the user on listview and every time the user scroll up/down the images of list being update
Is there any way to do this?
thanks in advance
In List View, getView() method of the BaseAdapter is called for only those views which are shown currently on screen. So you can use Nostra Universal Image Loader library to load the images asynchronously.
I have created five Horizontal ListView with images and texts in one activity. Using Lazy loading of images concept it is working fine. Now when it is offline, the list is showing blank,ie., no data . I need to implement memory-caching concept, such that when it is offline it will be showing the previous session datas(images & texts).
In oncreate: I am calling the Asynctask. In doinbackground method of asynctask,I am consuming Webservices containing images & texts,then I am passing those datas to the adapter. And in postexecute, I am setting my adapter to Listview.
In adapter class: getview method I am setting the texts and loading the images using lazy loading.
Please help me to get rid of this. Thanks in advance
You should store text etc. in an SQLiteDatabase and store your Images on external storage.
How do I implement a listview which displays images an text dynamically from the web? Each image has some descriptions to it and I need them to display correctly in each list. The images change every once in a while. So I have to retrieve up to date contents.
I have read this, but have no idea how to include text into it. Any help here?
Thanks.
Here you will find full details and along with Full working Source code
Android lazy image loader example
Use an ListView Adapter like here: http://android.amberfog.com/?p=296.
The getView Method is executed for every row of your ListView, so you have to place your code to load the images right there
When the Data changes simply call notifyDataSetChanged on the ListView Adapter and the ListView will refresh (executs getView again).
I am new Android developer. I want to achieve the following: On a particular screen (Activity) I have a grid view with images being set onto it. I have hundreds of thumbnail images coming from a server via http request. Now I don't want the gridview (with 4 columns in one row) to load the images in one go. Instead I want images to be loaded one row at a time (4 images), with other tiles of the grid view showing progess bar. Also when only few images are displayed the user should still be able to scroll the gridview vertically and thereby displaying empty gridview frames or tiles but if the scrolling is paused the frames or tiles of gridview are again loaded one row at a time.
I am looking for ideas to achieve this.
Thanks in advance for your responses.
In your Adapter's getView method set the image with a indefinite progress spinner.
After that start an AsyncTask to download the image if its not present in the object returned by getItem. Pass the item's position to the asynctask.
In AsyncTask's onPostExecute set the image to the view at position and hide the progress spinner.
Downloading the image in AsyncTask will ensure that your gridview is filled with items(empty) and responds to scrolling.