• GridView监听器


    package com.example.wang.testapp2;
    
    import android.os.Bundle;
    import android.support.v7.app.AppCompatActivity;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.AdapterView;
    import android.widget.BaseAdapter;
    import android.widget.GridView;
    import android.widget.ImageView;
    import android.widget.Toast;
    
    import java.util.ArrayList;
    import java.util.List;
    
    public class TestActivity10 extends AppCompatActivity {
    
        GridView gv_1;
    
        List<Integer> liv;
    
    
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_test10);
    
    
    
            //1-数据
            liv=new ArrayList<>();
            liv.add(R.drawable.f1);
            liv.add(R.drawable.f2);
            liv.add(R.drawable.f3);
            liv.add(R.drawable.f4);
            liv.add(R.drawable.f5);
            liv.add(R.drawable.f6);
            liv.add(R.drawable.f7);
            liv.add(R.drawable.f8);
    
            final ImageAdapter im=new ImageAdapter();
    
    
    
            gv_1=(GridView)findViewById(R.id.gv_1);
    
            gv_1.setAdapter(im);
    
            gv_1.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                @Override
                public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                    Toast.makeText(TestActivity10.this, "被点击的图片索引" + position, Toast.LENGTH_SHORT).show();
                }
            });
    
            //长按删除的监听器
            gv_1.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
                @Override
                public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
    
                    //1.实现删除数据
                    //从集合里删除长按的那一条
                    liv.remove(position);
    
                    //2.刷新视图,看到效果
                    //通知适配器,数据源改变了
                    im.notifyDataSetChanged();
                    Toast.makeText(TestActivity10.this, "删除了记录索引=" + position, Toast.LENGTH_SHORT).show();
                    return true;//事件已经被消费,不要在处理了
                }
            });
    
        }
        //适配器
    
        class  ImageAdapter extends BaseAdapter
        {
            @Override
            public int getCount() {
                return liv.size();
            }
    
            @Override
            public Object getItem(int position) {
                return liv.get(position);
            }
    
            @Override
            public long getItemId(int position) {
                return 0;
            }
    
            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
    
                //1-得到数据  图片的id
                Integer ivid=liv.get(position);
    
                //2-准备视图View
                if (convertView==null)
                {
                    convertView = new ImageView(TestActivity10.this);
                }
    
                //3-适配
                //项目转换
               ImageView imageView=(ImageView)convertView;
    
                imageView.setImageResource(ivid);
    
    //            imageView.setMaxWidth(70);
    //            imageView.setMaxHeight(70);
    
                imageView.setLayoutParams(new GridView.LayoutParams(120,120));
    
                return imageView;
            }
        }
    }
    java
    <?xml version="1.0" encoding="utf-8"?>
    <LinearLayout 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="com.example.wang.testapp2.TestActivity10">
        <GridView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/gv_1"
            android:numColumns="4"
            android:stretchMode="columnWidth"
            android:gravity="center"
            android:horizontalSpacing="30dp"
            android:verticalSpacing="30dp"
            android:columnWidth="120dp"></GridView>
    
    </LinearLayout>
    xml

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  • 原文地址:https://www.cnblogs.com/wangchuanqi/p/5515086.html
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