Question

最近,我试图利用和淡化可扩展的清单观点,因此,我 around绕了这一看法并 st了。

我几乎完全遵循了这些步骤,但我只建立了一个文件,以控制我自己的适应者的执行情况。我所说的主要活动的基本方法是:

mEntries = findViewById(R.id.entries);    
ExpandableListAdapter adapter = new MyExpandableListAdapter(this);
mEntries.setAdapter(adapter);

本条准则(摘自URL并修改):

import android.content.Context;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseExpandableListAdapter;
import android.widget.TextView;

public class MyExpandableListAdapter extends BaseExpandableListAdapter {
    private String[] groups = {"Vehicle", "Baj"};
    private String[][] children = {
        {"Mol", "Mor"},
        {"In", "Ruh"}
    };

    private Context cxt;

    public MyExpandableListAdapter(Context cxt) {
        this.cxt = cxt;
    }

    @Override
    public Object getChild(int groupPos, int childPos) {
        return children[groupPos][childPos];
    }

    @Override
    public long getChildId(int groupPos, int childPos) {
        return childPos;
    }

    @Override
    public View getChildView(int groupPos, int childPos,
            boolean isLastChild, View convertView, ViewGroup parent) {
        TextView tv = getGenericView();
        tv.setText(getChild(groupPos, childPos).toString());
        return tv;
    }

    @Override
    public int getChildrenCount(int groupPos) {
        return children[groupPos].length;
    }

    @Override
    public Object getGroup(int groupPos) {
        return groups[groupPos];
    }

    @Override
    public int getGroupCount() {
        return groups.length;
    }

    @Override
    public long getGroupId(int groupPos) {
        return groupPos;
    }

    public TextView getGenericView() {
        // Layout parameters for the ExpandableListView
        AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
            ViewGroup.LayoutParams.FILL_PARENT, 64);

        TextView tv = new TextView(this.cxt);
tv.setLayoutParams(lp);

        // Center the text vertically
        tv.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
        // Set the text starting position
        tv.setPadding(36, 0, 0, 0);
        return tv;
    }

    @Override
    public View getGroupView(int groupPos, boolean isExpanded, View convertView,
            ViewGroup parent) {
        TextView tv = getGenericView();
        tv.setText(getGroup(groupPos).toString());
        return null;
    }

    @Override
    public boolean hasStableIds() {
        return true;
    }

    @Override
    public boolean isChildSelectable(int groupPos, int childPos) {
        return true;
    }

}

log:

12-01 22:24:54.883: ERROR/AndroidRuntime(14424): java.lang.NullPointerException
12-01 22:24:54.883: ERROR/AndroidRuntime(14424):     at android.widget.AbsListView.obtainView(AbsListView.java:1276)
12-01 22:24:54.883: ERROR/AndroidRuntime(14424):     at android.widget.ListView.makeAndAddView(ListView.java:1668)
12-01 22:24:54.883: ERROR/AndroidRuntime(14424):     at android.widget.ListView.fillDown(ListView.java:637)
12-01 22:24:54.883: ERROR/AndroidRuntime(14424):     at android.widget.ListView.fillFromTop(ListView.java:694)
12-01 22:24:54.883: ERROR/AndroidRuntime(14424):     at android.widget.ListView.layoutChildren(ListView.java:1521)
12-01 22:24:54.883: ERROR/AndroidRuntime(14424):     at android.widget.AbsListView.onLayout(AbsListView.java:1113)
12-01 22:24:54.883: ERROR/AndroidRuntime(14424):     at android.view.View.layout(View.java:6830)
12-01 22:24:54.883: ERROR/AndroidRuntime(14424):     at android.widget.RelativeLayout.onLayout(RelativeLayout.java:900)
12-01 22:24:54.883: ERROR/AndroidRuntime(14424):     at android.view.View.layout(View.java:6830)
12-01 22:24:54.883: ERROR/AndroidRuntime(14424):     at android.widget.FrameLayout.onLayout(FrameLayout.java:333)
12-01 22:24:54.883: ERROR/AndroidRuntime(14424):     at android.view.View.layout(View.java:6830)
12-01 22:24:54.883: ERROR/AndroidRuntime(14424):     at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1119)
12-01 22:24:54.883: ERROR/AndroidRuntime(14424):     at android.widget.LinearLayout.layoutVertical(LinearLayout.java:998)
12-01 22:24:54.883: ERROR/AndroidRuntime(14424):     at android.widget.LinearLayout.onLayout(LinearLayout.java:918)
12-01 22:24:54.883: ERROR/AndroidRuntime(14424):     at android.view.View.layout(View.java:6830)
12-01 22:24:54.883: ERROR/AndroidRuntime(14424):     at android.widget.FrameLayout.onLayout(FrameLayout.java:333)
12-01 22:24:54.883: ERROR/AndroidRuntime(14424):     at android.view.View.layout(View.java:6830)
snip...

任何人都想对此作出说明? =

EDIT: I ve already implemented the methods required in the Base class.

EDIT2: Code added

Answer 1

最后,...... :

    @Override
public View getGroupView(int groupPos, boolean isExpanded, View convertView,
        ViewGroup parent) {
    TextView tv = getGenericView();
    tv.setText(getGroup(groupPos).toString());
    return null;
}

页: 1 在I m睡觉=/

Answer 2

当你延长可扩展的ListAdapter时,你仍需要执行如何显示每一行。否则,我认为,目前的 imp是把你看到的那点归来。因此,我还要执行:

public int getGroupCount()
public int getChildrenCount(int groupPosition)
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent)
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent)

我也执行了其他职能,但我没有显示这些职能。希望这一帮助。

友情链接