我已经从Vogella那里从http://www.vogella.com/articles/AndroidListView/article.html遵循了有关ListViews的上下文操作模式的教程。
无论如何,我要做的是有些不同。本教程中使用的数据是字符串的初始化数组。但是“我的数据”是从数据库中检索到的对象的列表。我怎样才能做到这一点?先谢谢您的帮助
这是名为MyPerformanceArrayAdapter.java的Custom ArrayAdapter的编码
package de.vogella.android.listactivity;
import android.app.Activity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;
public class MyPerformanceArrayAdapter extends ArrayAdapter<String> {
private final Activity context;
private final String[] names;
static class ViewHolder {
public TextView text;
public ImageView image;
}
public MyPerformanceArrayAdapter(Activity context, String[] names) {
super(context, R.layout.rowlayout, names);
this.context = context;
this.names = names;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View rowView = convertView;
if (rowView == null) {
LayoutInflater inflater = context.getLayoutInflater();
rowView = inflater.inflate(R.layout.rowlayout, null);
ViewHolder viewHolder = new ViewHolder();
viewHolder.text = (TextView) rowView.findViewById(R.id.TextView01);
viewHolder.image = (ImageView) rowView
.findViewById(R.id.ImageView01);
rowView.setTag(viewHolder);
}
ViewHolder holder = (ViewHolder) rowView.getTag();
String s = names[position];
holder.text.setText(s);
if (s.startsWith("Windows7") || s.startsWith("iPhone")
|| s.startsWith("Solaris")) {
holder.image.setImageResource(R.drawable.no);
} else {
holder.image.setImageResource(R.drawable.ok);
}
return rowView;
}
}
这是初始化String数据的活动代码
public class MyListActivityActionbar extends ListActivity {
protected Object mActionMode;
public int selectedItem = -1;
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);
String[] values = new String[] { "Android", "iPhone", "WindowsMobile",
"Blackberry", "WebOS", "Ubuntu", "Windows7", "Max OS X",
"Linux", "OS/2", "Ubuntu", "Windows7", "Max OS X", "Linux",
"OS/2", "Ubuntu", "Windows7", "Max OS X", "Linux", "OS/2" };
MySimpleArrayAdapter adapter = new MySimpleArrayAdapter(this, values);
setListAdapter(adapter);
getListView().setOnItemLongClickListener(new OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> parent, View view,
int position, long id) {
if (mActionMode != null) {
return false;
}
selectedItem = position;
// start the CAB using the ActionMode.Callback defined above
mActionMode = MyListActivityActionbar.this
.startActionMode(mActionModeCallback);
view.setSelected(true);
return true;
}
});
}
private ActionMode.Callback mActionModeCallback = new ActionMode.Callback() {
// called when the action mode is created; startActionMode() was called
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
// Inflate a menu resource providing context menu items
MenuInflater inflater = mode.getMenuInflater();
// assumes that you have "contexual.xml" menu resources
inflater.inflate(R.menu.rowselection, menu);
return true;
}
// the following method is called each time
// the action mode is shown. Always called after
// onCreateActionMode, but
// may be called multiple times if the mode is invalidated.
public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
return false; // Return false if nothing is done
}
// called when the user selects a contextual menu item
public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
switch (item.getItemId()) {
case R.id.menuitem1_show:
show();
// the Action was executed, close the CAB
mode.finish();
return true;
default:
return false;
}
}
// called when the user exits the action mode
public void onDestroyActionMode(ActionMode mode) {
mActionMode = null;
selectedItem = -1;
}
};
private void show() {
Toast.makeText(MyListActivityActionbar.this,
String.valueOf(selectedItem), Toast.LENGTH_LONG).show();
}
}
最佳答案
您的适配器类...
public class MyPerformanceArrayAdapter extends ArrayAdapter<String>
应该...
public class MyPerformanceArrayAdapter extends ArrayAdapter<T>
其中T是列表对象,而不是字符串。
这可能会有所帮助:ListView with objects tutorial