集册 Android 百战经典 百战经典第十二战-GridView动态删除Item

百战经典第十二战-GridView动态删除Item

欢马劈雪     最近更新时间:2020-08-04 05:37:59

187

用过UC浏览器的都熟悉如下功能:

这里写图片描述

长按图标会弹出删除的图标,点击删除会删除此项Item,下面研究一下如何实现类似效果。

1.配置布局main.xml文件:

<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" >  
    <GridView  
        android:id="@+id/gridView"  
        android:layout_width="match_parent"  
        android:layout_height="wrap_content"  
        android:numColumns="4" >  
    </GridView>  
</RelativeLayout>  

2.配置GridView的填充组件布局 grid_item.xml:

<?xml version="1.0" encoding="utf-8"?>  
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  
    android:id="@+id/ll_grid_item"  
    android:layout_width="match_parent"  
    android:layout_height="match_parent"  
    android:gravity="center"  
    android:orientation="vertical" >  
    <FrameLayout  
        android:id="@+id/starred_item_layout"  
        android:layout_width="fill_parent"  
        android:layout_height="wrap_content"  
        android:layout_gravity="center" >  
        <LinearLayout  
            android:layout_width="fill_parent"  
            android:layout_height="wrap_content"  
            android:layout_marginRight="4dip"  
            android:layout_marginTop="4dip"  
            android:gravity="center"  
            android:orientation="vertical" >  
            <ImageView  
                android:id="@+id/img"  
                android:layout_width="60dip"  
                android:layout_height="55dip" />  
            <TextView  
                android:id="@+id/name_tv"  
                android:layout_width="70dip"  
                android:layout_height="wrap_content"  
                android:layout_marginTop="10dip"  
                android:gravity="center"  
                android:textColor="@android:color/black"  
                android:textSize="15sp"  
                android:textStyle="bold" />  
        </LinearLayout>  
        <ImageView  
            android:id="@+id/delete_markView"  
            android:layout_width="20dip"  
            android:layout_height="20dip"  
            android:layout_gravity="right|top"  
            android:adjustViewBounds="true"  
            android:src="@drawable/delete"  
            android:visibility="gone" />  
    </FrameLayout>  
</LinearLayout> 

设置了id为delete_markView的ImageView的layout_gravity属性为right|top,说明该图片位于右上角,设置了其visibility为gone,说明该图片初始时是不显示的,后期可以控制该图片的显示。

3.adapter适配器文件:

package com.example.longdemo;  
//省略导入包
public class GridViewAdapter extends BaseAdapter {  
    private ArrayList<HashMap<String, Object>> myList;  
    private Context mContext;  
    private TextView name_tv;  
    private ImageView img;  
    private View deleteView;  
    private boolean isShowDelete=false;// 根据这个变量来判断是否显示删除图标,true是显示,false是不显示  
    public GridViewAdapter(Context mContext,  
            ArrayList<HashMap<String, Object>> myList) {  
        this.mContext = mContext;  
        // this.names=names;  
        this.myList = myList;  
    }  
    public void setIsShowDelete(boolean isShowDelete) {  
        this.isShowDelete = isShowDelete;  
        notifyDataSetChanged();  
    }  
    @Override  
    public int getCount() {  
        return myList.size();  
    }  
    @Override  
    public Object getItem(int position) {  
        return myList.get(position);  
    }  
    @Override  
    public long getItemId(int position) {  
        return position;  
    }  
    @Override  
    public View getView(int position, View convertView, ViewGroup parent) {  
        convertView = LayoutInflater.from(mContext).inflate(R.layout.grid_item,  
                null);  
        img = (ImageView) convertView.findViewById(R.id.img);  
        name_tv = (TextView) convertView.findViewById(R.id.name_tv);  
        deleteView = convertView.findViewById(R.id.delete_markView);  
        deleteView.setVisibility(isShowDelete ? View.VISIBLE : View.GONE);// 设置删除按钮是否显示  
        img.setBackgroundResource(myList.get(position).get("image").hashCode());  
        name_tv.setText(myList.get(position).get("name").toString());  
        return convertView;  
    }  
}

设置变量isShowDelete标识是否显示删除图标,默认是false 不显示,在getView方法中通过判断该标识,使用setVisibility方法控制删除图标的显示。同时定义了setIsShowDelete方法,供调用出调用以传入isShowDelete参数的值。

4.MainActivity.java:

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