Android listView的应用以及Activity跳转

最新推荐文章于 2021-10-25 21:48:54 发布

csdnbimingcong

最新推荐文章于 2021-10-25 21:48:54 发布

阅读量440

点赞数

CC 4.0 BY-SA版权

分类专栏： android

本文链接：https://blog.youkuaiyun.com/csdnbimingcong/article/details/48163119

android 专栏收录该内容

2 篇文章

订阅专栏

本文详细介绍了如何在Android应用中利用ListView展示一系列图像，并通过设置监听事件来接收其他活动返回的值，实现图像的选择与显示功能。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

OtherActivity

package com.example.listviewpassactivity;

import java.util.*;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;

public class OtherActivity extends Activity {

    protected static final int RESULTCODE = 1;
    private ListView listView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_other);

        final Intent intent = getIntent();

        listView = (ListView) findViewById(R.id.listView);
        final int[] images = { R.drawable.s2, R.drawable.tou1, R.drawable.tou3,
                R.drawable.ic_launcher };
        List list = new ArrayList<Integer>();
        for (int i = 0; i < images.length; i++)
            list.add(images[i]);
            //*********新建adapter
        MyAdapter adapter = new MyAdapter(this, list);
        listView.setAdapter(adapter);
        //***********设置监听事件
        listView.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                intent.putExtra("number", images[position]);
                setResult(RESULTCODE, intent);
                finish();
            }
        });

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.other, menu);
        return true;
    }

}

MainActivity

package com.example.listviewpassactivity;

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;

public class MainActivity extends Activity {

    protected static final int REQUESTCODE = 0;
    protected static final int RESULTCODE = 1;
    private Button btn;
    private ImageView iv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        btn = (Button) findViewById(R.id.btn);
        iv = (ImageView) findViewById(R.id.imageView);
        //*********************设置Button监听事件
        btn.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent intent = new Intent();
                intent.setClass(MainActivity.this, OtherActivity.class);
                //************8启动OtherActivity
                startActivityForResult(intent, REQUESTCODE);
            }
        });
    }

    @Override//***************接受OtherAcivity返回的值
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (REQUESTCODE == requestCode && resultCode == RESULTCODE) {
            int number = data.getIntExtra("number", 0);
            iv.setImageResource(number);
        }
        super.onActivityResult(requestCode, resultCode, data);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

MyAdapter

package com.example.listviewpassactivity;

import java.util.List;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;

public class MyAdapter extends BaseAdapter {
    private List<Integer> list;
    private Context context;

    MyAdapter(Context context, List<Integer> list) {
        this.list = list;
        this.context = context;
    }

    @Override
    public int getCount() {
        int count = 0;
        if (list != null)
            count = list.size();
        return count;
    }

    @Override
    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return list.get(position);
    }

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return position;
    }

    @Override//************优化过的getView（）方法能复用之前的convertView的布局对象 viewHolder就像是布局对象的引用
    public View getView(int position, View convertView, ViewGroup parent) {

        ViewHolder hold = null;
        if (convertView == null) {
            hold = new ViewHolder();
            convertView = LayoutInflater.from(context).inflate(R.layout.item,
                    null);
            hold.itemiv = (ImageView) convertView.findViewById(R.id.item_iv);
            convertView.setTag(hold);
        } else
            hold = (ViewHolder) convertView.getTag();
        hold.itemiv.setImageResource(list.get(position));
        return convertView;
    }

    class ViewHolder {
        private ImageView itemiv;
    }

}

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:gravity="center"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" 
    android:orientation="horizontal">

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/ic_launcher"
       android:id="@+id/imageView" />
    <Button
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:id="@+id/btn"
        android:text="选择"
        android:layout_marginLeft="10dp"
        />
</LinearLayout>

item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

<ImageView
    android:layout_height="wrap_content"
    android:layout_width="wrap_content"
    android:id="@+id/item_iv"
    />
</LinearLayout>

activity_other.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".OtherActivity" >

    <ListView
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
       android:id="@+id/listView"/>

</RelativeLayout>