用过UC浏览器的都熟悉如下功能:
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: