CODEWITHSUNDEEP
androidlistview
David Yao
David Yao

Reputation: 127

ListView app frustratingly slow, unable to figure out why

Everything seems to be okay (other than being quite laggy) except the fact that I am unable to see the last few views of my ListView app. I tried to change the height of my custom view layout for each ListView item and I realized that the smaller the height, the more views I could not see. This meant that there was a fixed length of height at the bottom of my ListView that I am unable to scroll to and I have no idea why.

Code from MainActivity.java

public class MainActivity extends AppCompatActivity {

    String[] titles;
    String[] descriptions;
    int[] drawables = {R.drawable.number0, R.drawable.number2, R.drawable.number3, R.drawable.number4, R.drawable.number5, R.drawable.number6, R.drawable.number7, R.drawable.number8, R.drawable.number9, R.drawable.number10};

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Resources res = getResources();
        titles = res.getStringArray(R.array.title);
        descriptions = res.getStringArray(R.array.description);

        ListView l = (ListView) findViewById(R.id.listview);
        myadapter myadapter = new myadapter(this, titles, drawables, descriptions);
        l.setAdapter(myadapter);

    }
}
class myadapter extends ArrayAdapter<String>{
        Context c;
        int[] drawables;
        String[] titles;
        String[] descriptions;

    public myadapter(Context context, String[] titles, int[] drawables, String[] descriptions ) {
        super(context,R.layout.single_row, R.id.title,titles);
        c=context;
        this.drawables = drawables;
        this.titles = titles;
        this.descriptions = descriptions;
    }

    public View getView(int position,  View convertView,  ViewGroup parent) {
        View v = convertView;
        if (v == null) {
            LayoutInflater i = (LayoutInflater) c.getSystemService(c.LAYOUT_INFLATER_SERVICE);
            v = i.inflate(R.layout.single_row, parent, false);
        }
        ImageView image = (ImageView) v.findViewById(R.id.image);
        TextView title = (TextView) v.findViewById(R.id.title);
        TextView description = (TextView) v.findViewById(R.id.description);

        image.setImageResource(drawables[position]);
        title.setText(titles[position]);
        description.setText(descriptions[position]);

        return v;
    }
}

Code from custom layout xml file:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/relative_layout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    tools:layout_editor_absoluteX="8dp"
    tools:layout_editor_absoluteY="8dp">

    <ImageView
        android:id="@+id/image"
        android:layout_width="90dp"
        android:layout_height="90dp"
        app:srcCompat="@drawable/number0" />

    <TextView
        android:id="@+id/title"
        android:layout_width="332dp"
        android:layout_height="36dp"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:layout_toEndOf="@+id/image"
        android:layout_toRightOf="@+id/image" />

    <TextView
        android:id="@+id/description"
        android:layout_width="320dp"
        android:layout_height="49dp"
        android:layout_below="@+id/title"
        android:layout_alignStart="@id/title"
        android:layout_alignLeft="@id/title"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:layout_toEndOf="@+id/image"
        android:layout_toRightOf="@+id/image" />
</RelativeLayout>

The activity_main.xml file simply contains a listview.

Upvotes: 2

Views: 60

Answers (1)

Peter
Peter

Reputation: 467

the video tutorial uses a png file format, he might have used smaller files instead. Your list view might be slow because it takes time to draw so many resources to display it? Did u try just displaying the text only?

sorry this is more like a comment than a answer, but I can't post comments till I've reached 50 reps

Upvotes: 1

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