java - 自动更改android中最新 ListView 项的背景颜色

Question

这是来自 ODK COLLECT 的代码!我想更改所选 ListView 项或表单的背景颜色。我试图寻找有关如何动态更改最新列表项的背景颜色的解决方案但没有成功任何人都可以帮助我解决方案

这是 FORMCHOOSER Activity

**

/*
 * Copyright (C) 2009 University of Washington
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */


 package org.odk.collect.android.activities;
    import android.app.AlertDialog;
    import android.content.ContentUris;
    import android.content.DialogInterface;
    import android.content.Intent;
    import android.database.Cursor;
    import android.net.Uri;
    import android.os.AsyncTask;
    import android.os.Bundle;
    import android.view.View;
    import android.widget.AdapterView;
    import android.widget.TextView;
    import org.odk.collect.android.R;
    import org.odk.collect.android.application.Collect;
    import org.odk.collect.android.dao.FormsDao;
    import org.odk.collect.android.listeners.DiskSyncListener;
    import org.odk.collect.android.provider.FormsProviderAPI.FormsColumns;
    import org.odk.collect.android.tasks.DiskSyncTask;
    import org.odk.collect.android.utilities.ApplicationConstants;
    import org.odk.collect.android.utilities.VersionHidingCursorAdapter;
    import timber.log.Timber;
    /**
     * Responsible for displaying all the valid forms in the forms directory. Stores the path to
     * selected form for use by {@link MainMenuActivity}.
     *
     * @author Yaw Anokwa (yanokwa@gmail.com)
     * @author Carl Hartung (carlhartung@gmail.com)
     */
    public class FormChooserList extends FormListActivity implements DiskSyncListener, AdapterView.OnItemClickListener {
        private static final String FORM_CHOOSER_LIST_SORTING_ORDER = "formChooserListSortingOrder";
        private static final boolean EXIT = true;
        private static final String syncMsgKey = "syncmsgkey";
        private DiskSyncTask diskSyncTask;
        @Override
        public void onCreate(Bundle savedInstanceState) {
            // must be at the beginning of any activity that can be called from an external intent
            try {
                Collect.createODKDirs();
            } catch (RuntimeException e) {
                createErrorDialog(e.getMessage(), EXIT);
                return;
            }
            setContentView(R.layout.chooser_list_layout);
            super.onCreate(savedInstanceState);
            setTitle(getString(R.string.enter_data));
            setupAdapter();
            if (savedInstanceState != null && savedInstanceState.containsKey(syncMsgKey)) {
                TextView tv = (TextView) findViewById(R.id.status_text);
                tv.setText((savedInstanceState.getString(syncMsgKey)).trim());
            }
            // DiskSyncTask checks the disk for any forms not already in the content provider
            // that is, put here by dragging and dropping onto the SDCard
            diskSyncTask = (DiskSyncTask) getLastCustomNonConfigurationInstance();
            if (diskSyncTask == null) {
                Timber.i("Starting new disk sync task");
                diskSyncTask = new DiskSyncTask();
                diskSyncTask.setDiskSyncListener(this);
                diskSyncTask.execute((Void[]) null);
            }
            sortingOptions = new String[]{
                    getString(R.string.sort_by_name_asc), getString(R.string.sort_by_name_desc),
                    getString(R.string.sort_by_date_asc), getString(R.string.sort_by_date_desc),
            };
        }
        @Override
        public Object onRetainCustomNonConfigurationInstance() {
            // pass the thread on restart
            return diskSyncTask;
        }
        @Override
        protected void onSaveInstanceState(Bundle outState) {
            super.onSaveInstanceState(outState);
            TextView tv = (TextView) findViewById(R.id.status_text);
            outState.putString(syncMsgKey, tv.getText().toString().trim());
        }
        /**
         * Stores the path of selected form and finishes.
         */
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            // get uri to form
            long idFormsTable = listView.getAdapter().getItemId(position);
            Uri formUri = ContentUris.withAppendedId(FormsColumns.CONTENT_URI, idFormsTable);
            Collect.getInstance().getActivityLogger().logAction(this, "onListItemClick",
                    formUri.toString());
            String action = getIntent().getAction();
            if (Intent.ACTION_PICK.equals(action)) {
                // caller is waiting on a picked form
                setResult(RESULT_OK, new Intent().setData(formUri));
            } else {
                // caller wants to view/edit a form, so launch formentryactivity
                Intent intent = new Intent(Intent.ACTION_EDIT, formUri);
                intent.putExtra(ApplicationConstants.BundleKeys.FORM_MODE, ApplicationConstants.FormModes.EDIT_SAVED);
                startActivity(intent);
            }
            finish();
        }
        @Override
        protected void onResume() {
            diskSyncTask.setDiskSyncListener(this);
            super.onResume();
            if (diskSyncTask.getStatus() == AsyncTask.Status.FINISHED) {
                syncComplete(diskSyncTask.getStatusMessage());
            }
        }
        @Override
        protected void onPause() {
            diskSyncTask.setDiskSyncListener(null);
            super.onPause();
        }
        @Override
        protected void onStart() {
            super.onStart();
            Collect.getInstance().getActivityLogger().logOnStart(this);
        }
        @Override
        protected void onStop() {
            Collect.getInstance().getActivityLogger().logOnStop(this);
            super.onStop();
        }
        /**
         * Called by DiskSyncTask when the task is finished
         */
        @Override
        public void syncComplete(String result) {
            Timber.i("Disk sync task complete");
            TextView tv = (TextView) findViewById(R.id.status_text);
            tv.setText(result.trim());
        }
        private void setupAdapter() {
            String[] data = new String[]{
                    FormsColumns.DISPLAY_NAME, FormsColumns.DISPLAY_SUBTEXT, FormsColumns.JR_VERSION
            };
            int[] view = new int[]{
                    R.id.text1, R.id.text2, R.id.text3
            };
            listAdapter =
                    new VersionHidingCursorAdapter(FormsColumns.JR_VERSION, this, R.layout.two_item, getCursor(), data, view);
            listView.setAdapter(listAdapter);
        }
        @Override
        protected String getSortingOrderKey() {
            return FORM_CHOOSER_LIST_SORTING_ORDER;
        }
        @Override
        protected void updateAdapter() {
            listAdapter.changeCursor(getCursor());
        }
        private Cursor getCursor() {
            return new FormsDao().getFormsCursor(getFilterText(), getSortingOrder());
        }
        /**
         * Creates a dialog with the given message. Will exit the activity when the user preses "ok" if
         * shouldExit is set to true.
         */
        private void createErrorDialog(String errorMsg, final boolean shouldExit) {
            Collect.getInstance().getActivityLogger().logAction(this, "createErrorDialog", "show");
            AlertDialog alertDialog = new AlertDialog.Builder(this).create();
            alertDialog.setIcon(android.R.drawable.ic_dialog_info);
            alertDialog.setMessage(errorMsg);
            DialogInterface.OnClickListener errorListener = new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int i) {
                    switch (i) {
                        case DialogInterface.BUTTON_POSITIVE:
                            Collect.getInstance().getActivityLogger().logAction(this,
                                    "createErrorDialog",
                                    shouldExit ? "exitApplication" : "OK");
                            if (shouldExit) {
                                finish();
                            }
                            break;
                    }
                }
            };
            alertDialog.setCancelable(false);
            alertDialog.setButton(getString(R.string.ok), errorListener);
            alertDialog.show();

**
    }
}

这是布局

**



     <?xml version="1.0" encoding="utf-8"?><!-- Copyright (C) 2009 University of Washington
        Licensed under the Apache License, Version 2.0 (the "License"); you may not
        use this file except in compliance with the License. You may obtain a copy of
        the License at
        http://www.apache.org/licenses/LICENSE-2.0
        Unless required by applicable law or agreed to in writing, software
        distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
        WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
        License for the specific language governing permissions and limitations under
        the License.
        -->
        <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                        android:layout_width="match_parent"
                        android:layout_height="match_parent">
            <!-- Toolbar -->
            <include layout="@layout/toolbar"/>
            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_below="@id/toolbar"
                android:orientation="vertical">
                <TextView
                    android:id="@+id/status_text"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:background="#DDDDDD"
                    android:paddingBottom="4dip"
                    android:paddingEnd="8dip"
                    android:paddingLeft="8dip"
                    android:paddingRight="8dip"
                    android:paddingStart="8dip"
                    android:paddingTop="4dip"
                    android:text="@string/form_scan_starting"
                    android:textSize="14sp"/>
                <ListView
                    android:id="@id/android:list"
                    android:layout_width="match_parent"
                    android:layout_height="0dp"
                    android:layout_weight="1"/>
                <TextView
                    android:id="@android:id/empty"
                    style="@style/emptyViewStyle"
                    android:text="@string/no_items_display_forms"/>
            </LinearLayout>
            <include
                layout="@layout/toolbar_action_bar_shadow"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_below="@id/toolbar"/>
        </RelativeLayout>

    **

Answer 1

在 onItemClick() 方法中尝试调用 view.setBackgroundResource(color)