Java 如何创建Listview,以便单击每个列表项将打开不同的活动?
我有一个列表视图。我想点击每个列表项,它会打开不同的活动。实际上,我写了代码,但它不起作用。我的编码技能无法处理这个问题。如何使用字符串和类对创建一个Hahmap,然后将其放入ArrayAdapter。谁能告诉我密码吗 ListViewAcivity.javaJava 如何创建Listview,以便单击每个列表项将打开不同的活动?,java,android,listview,Java,Android,Listview,我有一个列表视图。我想点击每个列表项,它会打开不同的活动。实际上,我写了代码,但它不起作用。我的编码技能无法处理这个问题。如何使用字符串和类对创建一个Hahmap,然后将其放入ArrayAdapter。谁能告诉我密码吗 ListViewAcivity.java import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
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 java.util.HashMap;
public class ListViewActivity extends Activity {
ListView listView ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_screen_activity);
// Get ListView object from xml
listView = (ListView) findViewById(R.id.list);
// Defined Array values to show in ListView
HashMap<String, Class> hashMap=new HashMap<String, Class>();
hashMap.put("A Function", MActivity.class);
hashMap.put("B Function",AActivity.class);
hashMap.put("c Function",XActivity.class);
hashMap.put("D Function",ZActivity.class);
hashMap.put("E Function", PActivity.class);
hashMap.put("F Function", QActivity.class);
// Define a new Adapter
// First parameter - Context
// Second parameter - Layout for the row
// Third parameter - ID of the TextView to which the data is written
// Forth - the Array of data
导入android.app.Activity;
导入android.content.Intent;
导入android.os.Bundle;
导入android.view.view;
导入android.widget.AdapterView;
导入android.widget.ArrayAdapter;
导入android.widget.ListView;
导入android.widget.Toast;
导入java.util.ArrayList;
导入java.util.HashMap;
公共类ListViewActivity扩展活动{
列表视图列表视图;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main\u屏幕\u活动);
//从xml获取ListView对象
listView=(listView)findViewById(R.id.list);
//要在ListView中显示的已定义数组值
HashMap HashMap=新的HashMap();
put(“函数”,MActivity.class);
put(“B函数”,aaactivity.class);
put(“c函数”,XActivity.class);
put(“D函数”,ZActivity.class);
put(“E函数”,PActivity.class);
put(“F函数”,QActivity.class);
//定义一个新适配器
//第一个参数-上下文
//第二个参数-行的布局
//第三个参数-写入数据的TextView的ID
//第四,数据数组
//这里有错误……//无法解决此构造函数//我不知道如何使用//字符串、类对和数组适配器
ArrayAdapter<HashMap<String,Class>> adapter = new ArrayAdapter<HashMap<String,Class>>(this, android.R.layout.simple_list_item_1, android.R.id.text1, hashMap);
// Assign adapter to ListView
listView.setAdapter(adapter);
// ListView Item Click Listener
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// ListView Clicked item index
int itemPosition = position;
// ListView Clicked item value
String itemValue = (String) listView.getItemAtPosition(position);
switch(itemPosition){
case 0: Intent newActivity = new Intent(ListViewActivity.this, MActivity.class);
startActivity(newActivity);
break;
case 1: Intent newActivity1 = new Intent(ListViewActivity.this, AActivity.class);
startActivity(newActivity1);
break;
case 2: Intent newActivity2 = new Intent(ListViewActivity.this, XActivity.class);
startActivity(newActivity2);
break;
case 3: Intent newActivity3 = new Intent(ListViewActivity.this, ZActivity.class);
startActivity(newActivity3);
break;
case 4: Intent newActivity4 = new Intent(ListViewActivity.this, PActivity.class);
startActivity(newActivity4);
break;
case 5: Intent newActivity5 = new Intent(ListViewActivity.this, QActivity.class);
startActivity(newActivity5);
break;
}
}
@SuppressWarnings("unused")
public void onClick(View v){
};
});}
}
ArrayAdapter adapter=新的ArrayAdapter(这个,android.R.layout.simple_list_item_1,android.R.id.text1,hashMap);
//将适配器分配给ListView
setAdapter(适配器);
//ListView项目单击侦听器
setOnItemClickListener(新的AdapterView.OnItemClickListener(){
@凌驾
public void onItemClick(AdapterView父级、视图、,
内部位置,长id){
//ListView单击的项目索引
int itemPosition=位置;
//ListView单击的项目值
String itemValue=(String)listView.getItemAtPosition(position);
开关(位置){
案例0:Intent newActivity=newintent(ListViewActivity.this,MActivity.class);
星触觉(新活动);
打破
案例1:Intent newActivity1=新的Intent(ListViewActivity.this,aaActivity.class);
startActivity(新活动1);
打破
案例2:Intent newActivity2=新的Intent(ListViewActivity.this,xaActivity.class);
startActivity(新活动2);
打破
案例3:Intent newActivity3=新Intent(ListViewActivity.this,zaActivity.class);
startActivity(新活动3);
打破
案例4:Intent newActivity4=新Intent(ListViewActivity.this,PActivity.class);
startActivity(新活动4);
打破
案例5:Intent newActivity5=新的Intent(ListViewActivity.this,QActivity.class);
startActivity(新活动5);
打破
}
}
@抑制警告(“未使用”)
公共void onClick(视图v){
};
});}
}
主屏幕\u Activity.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ListView
android:id="@+id/list"
android:layout_width="match_parent"
android:layout_height="wrap_content"></ListView>
</LinearLayout>
An需要显示对象的数组或列表。因此,您需要提供一个数组/列表
是什么让您认为它可以处理地图?列表/数组表示事物的序列;而地图代表的是从某种东西到另一种东西的映射
换句话说:您不能传递贴图对象
只需传递包含要显示的字符串的列表或数组(“医疗提醒”、…)
但拥有这张地图是有价值的;您只需稍微更改一下代码:
首先,在创建ArrayAdapter时,可以使用贴图的键作为输入,如下所示:
List<String> arrayItems = new ArrayList<>(hashMap.keySet());
您所要求的功能的简单静态示例
public class MainActivity extends AppCompatActivity {
ListView lv1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Initialize the list view
lv1 = (ListView) findViewById(R.id.mainlist);
//Add the List data
//as the array is stored starting with 0, the Layouts will be having 0th position, Intents being 1 and so on..
String[] sessiontuts = new String[]{"Activity 1", "Activity2"};
//use the Simple array adapter
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,android.R.id.text1,sessiontuts);
//now to bind the data to list, just set the adapter we just created to the listview,
lv1.setAdapter(adapter);
//we need to have click listner on the particular item,
//all the items in list will have a position starting from 0 to n,
//so, write the intent code to launch particular activity depending on list item position
lv1.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int pos, long l) {
//using switch case, to check the condition.
switch (pos){
case 0:
startActivity(new Intent(getApplicationContext(), Act1.class));
break;
case 1:
startActivity(new Intent(getApplicationContext(), Act2.class));
break;
}
}
});
}
}
public类MainActivity扩展了AppCompatActivity{
ListView lv1;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//初始化列表视图
lv1=(ListView)findViewById(R.id.mainlist);
//添加列表数据
//当数组从0开始存储时,布局将处于第0位,意图为1,依此类推。。
String[]sessionuts=新字符串[]{“活动1”、“活动2”};
//使用简单阵列适配器
ArrayAdapter=新的ArrayAdapter(这个,android.R.layout.simple_list_item_1,android.R.id.text1,sessionuts);
//现在要将数据绑定到列表,只需将刚刚创建的适配器设置为listview,
lv1.设置适配器(适配器);
//我们需要在特定项目上单击listner,
//列表中的所有项目都将有一个从0到n的位置,
//因此,根据列表项的位置编写启动特定活动的意图代码
lv1.setOnItemClickListener(新的AdapterView.OnItemClickListener(){
@凌驾
公共虚线单击(AdapterView AdapterView,视图视图,内部位置,长l){
//使用开关箱,检查
public class MainActivity extends AppCompatActivity {
ListView lv1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Initialize the list view
lv1 = (ListView) findViewById(R.id.mainlist);
//Add the List data
//as the array is stored starting with 0, the Layouts will be having 0th position, Intents being 1 and so on..
String[] sessiontuts = new String[]{"Activity 1", "Activity2"};
//use the Simple array adapter
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,android.R.id.text1,sessiontuts);
//now to bind the data to list, just set the adapter we just created to the listview,
lv1.setAdapter(adapter);
//we need to have click listner on the particular item,
//all the items in list will have a position starting from 0 to n,
//so, write the intent code to launch particular activity depending on list item position
lv1.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int pos, long l) {
//using switch case, to check the condition.
switch (pos){
case 0:
startActivity(new Intent(getApplicationContext(), Act1.class));
break;
case 1:
startActivity(new Intent(getApplicationContext(), Act2.class));
break;
}
}
});
}
}