我无法在任何地方找到答案。我有一个包含24个项目的菜单。我希望用户能够使用“设置”选择要在菜单上显示的24个项目。我不能为此制定战略。有没有人有任何想法？我没有代码，因为我不知道从哪里开始，除了使用Setiings的基础知识。
我不确定为什么在没有解释的情况下将其拒之门外。问题太混乱了吗？
答案 0 :(得分：0)
这是我在了解了ListView可以做的事情之后最终得到的：
XML
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.triunedev.custommenucode.MainActivity">
<ListView
android:id="@+id/outOfMenuList"
android:layout_width="0dp"
android:layout_height="200dp"
android:layout_marginTop="10dp"
android:choiceMode="multipleChoice"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0" />
<LinearLayout
android:id="@+id/moveArrows"
android:layout_width="0dp"
android:layout_height="36dp"
android:layout_marginBottom="10dp"
android:layout_marginTop="10dp"
android:orientation="horizontal"
app:layout_constraintBottom_toTopOf="@+id/insideMenuList"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/outOfMenuList">
<ImageView
android:id="@+id/addArrow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="100dp"
android:layout_weight="2"
android:contentDescription="@string/in_arrow"
android:onClick="moveItem"
android:visibility="visible"
app:srcCompat="@drawable/arrow_down" />
<ImageView
android:id="@+id/removeArrow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="100dp"
android:layout_weight="2"
android:contentDescription="@string/out_arrow"
android:onClick="moveItem"
android:visibility="visible"
app:srcCompat="@drawable/arrow_up" />
</LinearLayout>
<ListView
android:id="@+id/insideMenuList"
android:layout_width="0dp"
android:layout_height="200dp"
android:choiceMode="multipleChoice"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/moveArrows"
app:layout_constraintVertical_bias="0.0" />
</android.support.constraint.ConstraintLayout>
JAVA
package com.triunedev.custommenucode;
import android.graphics.Color;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
import static java.util.Arrays.asList;
public class MainActivity extends AppCompatActivity {
ListView insideMenuList;
ListView outOfMenuList;
ArrayList<String> insideMenuArray;
ArrayList<String> outOfMenuArray;
ArrayAdapter<String> outOfMenuAdapter;
ArrayAdapter<String> insideMenuAdapter;
int count;
String listInFocus;
String[] toMoveToMenuList;
String[] toMoveOutOfMenuList = new String[24];
public void buildListArrays() {
insideMenuList = (ListView) findViewById(R.id.insideMenuList);
outOfMenuList = (ListView) findViewById(R.id.outOfMenuList);
insideMenuArray = new ArrayList<String>(asList(
"Chick-fil-A",
"In-N-Out Burger",
"Wendys",
"Dairy Queen",
"Kentucky Fried Chicken",
"Carl's Jr.",
"McDonald's",
"Sonic",
"Jack-in-the-Box",
"Taco Bell",
"Burger King",
"Arby's",
"El Pollo Loco",
"Popeye's",
"Starbucks",
"Panda Express",
"Steak 'n Shake",
"Jersey Mike's",
"A&W",
"Whitecastle",
"Hardee's",
"Del Taco",
"Subway",
"Long John Silver's"));
outOfMenuArray = new ArrayList<String>(asList(
"Auntie Anne's",
"Cinnabon",
"Dunkin' Donuts",
"Pizza Hut",
"Panera Bread",
"Domino's",
"Chipotle",
"Little Caesars",
"Papa John's",
"Jimmy John's",
"Zaxby's",
"Culver's",
"Bojangles'",
"Church's Chicken",
"Papa Murphy's",
"Baskin-Robbins",
"Jamba Juice",
"Coldstone Creamery",
"Five Guys",
"Jollibee",
"Krispy Kreme",
"Hook Burger",
"Quizno's",
"Coffee Bean & Tea Leaf",
"TCBY",
"Tim Hortons",
"Wingstop",
"WingStreet"));
populateListViews();
insideMenuList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long l) {
if(listInFocus.equals("outOfMenuList")) {
outOfMenuList.setAdapter(outOfMenuAdapter);
count = 0;
}
parent.getChildAt(position).setBackgroundColor(Color.argb(100, 255, 242, 99));
toMoveOutOfMenuList[position] = insideMenuArray.get(position);
count++;
listInFocus = parent.getResources().getResourceEntryName(parent.getId());
}
});
outOfMenuList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long l) {
if(listInFocus.equals("insideMenuList")) {
insideMenuList.setAdapter(insideMenuAdapter);
count = 0;
}
parent.getChildAt(position).setBackgroundColor(Color.argb(100, 255, 242, 99));
toMoveToMenuList[position] = outOfMenuArray.get(position);
count++;
listInFocus = parent.getResources().getResourceEntryName(parent.getId());
}
});
}
public void populateListViews() {
toMoveToMenuList = new String[outOfMenuArray.size()];
for(int i=0; i<outOfMenuArray.size(); i++) {
toMoveToMenuList[i] = "empty";
}
for(int i=0; i<24; i++) {
toMoveOutOfMenuList[i] = "empty";
}
insideMenuAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, insideMenuArray);
insideMenuList.setAdapter(insideMenuAdapter);
outOfMenuAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, outOfMenuArray);
outOfMenuList.setAdapter(outOfMenuAdapter);
listInFocus = "";
count = 0;
}
public void moveItem(View view) {
String id = view.getResources().getResourceEntryName(view.getId());
if((id.equals("removeArrow") || id.equals("addArrow")) && listInFocus.equals("")) {
Toast.makeText(getApplicationContext(), "Please choose an item to move.", Toast.LENGTH_LONG).show();
}
else {
if (id.equals("addArrow") && listInFocus.equals("outOfMenuList")) {
if (insideMenuArray.size() <= 24 - count) {
for(int i=0, j=0; i<outOfMenuArray.size(); i++) {
if(!toMoveToMenuList[i].equals("empty")) {
insideMenuArray.add(toMoveToMenuList[i]);
outOfMenuArray.remove(i - j);
j++;
}
}
}
else Toast.makeText(getApplicationContext(), "List already contains 24 items.\nYou will need to remove 1 or more items\nbefore adding any", Toast.LENGTH_LONG).show();
}
else if (id.equals("removeArrow") && listInFocus.equals("insideMenuList")) {
for(int i=0, j=0; i<24; i++) {
if(!toMoveOutOfMenuList[i].equals("empty")) {
outOfMenuArray.add(toMoveOutOfMenuList[i]);
insideMenuArray.remove(i - j);
j++;
}
}
}
else Toast.makeText(getApplicationContext(), "An item cannot be moved to its own list.", Toast.LENGTH_LONG).show();
populateListViews();
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
buildListArrays();
}
}
现在我将研究如何将它集成到我正在构建的应用程序中。