Android学习笔记⑧——UI组件的学习AdapterView相关2

前面都是用ListView控件来配合Adapter做的一些实例，这次我们来见识一下GridView与Adapter之间的爱恨情仇。。。。

GridView是用于在界面上按行、列分布的方式来显示多个的组件，与ListView相似，但是比ListView高级，因为他可以一下子有多个列，而ListView只有一列。

GridView设置一个简单的图片浏览器

大概功能就是 点击一下图片，然后下方显示放大的图。。。

主布局代码：

 <?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">

     <GridView
         android:id="@+id/gridview"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:gravity="center"
         android:horizontalSpacing="1pt"
         android:numColumns="4"
         android:verticalSpacing="1pt">
     </GridView>

     <ImageView
         android:id="@+id/imageshow"
         android:layout_width="250dp"
         android:layout_height="250dp"
         android:layout_gravity="center_horizontal"
         />
 </LinearLayout>

用与ImageView布局的 代码：

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

     <ImageView
         android:id="@+id/image"
         android:layout_width="70dp"
         android:layout_height="70dp"
         android:layout_margin="5dp"
         android:scaleType="fitXY"
         />
 </LinearLayout>

java代码：

 package com.doliao.helloworld;

 import android.app.Activity;
 import android.os.Bundle;
 import android.view.View;
 import android.widget.AdapterView;
 import android.widget.GridView;
 import android.widget.ImageView;
 import android.widget.SimpleAdapter;

 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;

 /**
  * Created by Administrator on 2016/10/12 0012.
  */

 public class GridViewActivity extends Activity {

     GridView gridView;
     ImageView imageView;
     int[] imageids = new int[]{R.drawable.pic1, R.drawable.pic2, R.drawable.pic3, R.drawable.pic4, R.drawable.pic5, R.drawable.pic6
             , R.drawable.pic7, R.drawable.pic8, R.drawable.pic9, R.drawable.pic10, R.drawable.pic11, R.drawable.pic12};

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

         gridView = (GridView) findViewById(R.id.gridview);
         imageView = (ImageView) findViewById(R.id.imageshow);

         List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
         for (int imageid : imageids) {
             Map<String, Object> map = new HashMap<String, Object>();
             map.put("imageid", imageid);
             list.add(map);
         }
         SimpleAdapter simpleAdapter = new SimpleAdapter(this, list, R.layout.all_images,
                 new String[]{"imageid"}, new int[]{R.id.image});
         gridView.setAdapter(simpleAdapter);

         gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
             @Override
             public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                 imageView.setImageResource(imageids[position]);
             }
         });
     }
 }

运行的显示截图如下：

 ExpandableListView (可展开的列表组件)

ExpandableListView是List的子类，在基本的List上面进行了扩展，他把列表分为几组，每组里面又可以包含多个列表现。简单的来说就相当于QQ列表一样，有分组，分组里面又有好多的好友列表。这么高级的组件本身也是傲娇的，他有自己御用的Adapter——ExpandableListAdapter。EXpandableAdapter与Adapter相似，一般实现的方法有三种：

1、扩展BaseExpandableLIstAdapter实现的ExpandableListAdapter；

2、使用SimpleExpandableListAdapter将两个list集合包装成ExpandableListAdapter

3、使用SimpleCursorTreeAdapter将Cursor中的数据包装成SimpleCursorTreeAdapter。

布局代码：activity_expandablelistview.xml

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

     <ExpandableListView
         android:id="@+id/expand"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content">

     </ExpandableListView>
 </LinearLayout>

Java代码： ExpandableListViewActivity.java

 package com.doliao.helloworld;

 import android.app.Activity;
 import android.os.Bundle;
 import android.view.Gravity;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.AbsListView;
 import android.widget.BaseExpandableListAdapter;
 import android.widget.ExpandableListAdapter;
 import android.widget.ExpandableListView;
 import android.widget.LinearLayout;
 import android.widget.TextView;

 /**
  * Created by Administrator on 2016/10/13 0013.
  */

 public class ExpandableListViewActivity extends Activity {

     //定义列表组
     String[] listType = new String[]{"名著列表", "小说列表", "动漫列表"};
     //每个列表组下面的数据
     String[][] lists = new String[][]{
             {"西游记", "水浒传", "红楼梦"},
             {"择天记", "星辰变", "间客"},
             {"海贼王", "火影忍者", "死神"}
     };

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

         ExpandableListAdapter expandableListAdapter = new BaseExpandableListAdapter() {

             @Override
             public int getGroupCount() {
                 return lists.length;
             }

             @Override
             public int getChildrenCount(int groupPosition) {
                 return lists[groupPosition].length;
             }

             @Override
             public Object getGroup(int groupPosition) {
                 return listType[groupPosition];
             }

             @Override
             public Object getChild(int groupPosition, int childPosition) {
                 return lists[groupPosition][childPosition];
             }

             @Override
             public long getGroupId(int groupPosition) {
                 return groupPosition;
             }

             @Override
             public long getChildId(int groupPosition, int childPosition) {
                 return childPosition;
             }

             @Override
             public boolean hasStableIds() {
                 return true;
             }

             @Override
             public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {

                 //View view = View.inflate(ExpandableListViewActivity.this, R.layout.autotext, null);
                 //TextView textView = (TextView) findViewById(R.layout.autotext);

                 /*View view = View.inflate(ExpandableListViewActivity.this, R.layout.linear_text, null);
                 TextView textView = (TextView) findViewById(R.id.text1);
                 textView.setText(getGroup(groupPosition).toString());
                 view.setLayoutParams();*/

                 LinearLayout ll = new LinearLayout(ExpandableListViewActivity.this);
                 TextView textView = getTextView();
                 textView.setText(getGroup(groupPosition).toString());
                 ll.addView(textView);
                 return ll;

             }

             @Override
             public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
                 //TextView textView = (TextView) findViewById(R.id.autotext);
                 //textView.setText(getChild(groupPosition, childPosition).toString());
                 TextView textView = getTextView();
                 textView.setText(getChild(groupPosition, childPosition).toString());
                 return textView;
             }

             @Override
             public boolean isChildSelectable(int groupPosition, int childPosition) {
                 return true;
             }
         };

         ExpandableListView expandableListView = (ExpandableListView) findViewById(R.id.expand);
         expandableListView.setAdapter(expandableListAdapter);
     }

     private TextView getTextView() {
         AbsListView.LayoutParams lp = new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 64);
         TextView textView = new TextView(ExpandableListViewActivity.this);
         textView.setLayoutParams(lp);
         textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
         textView.setPadding(36, 0, 0, 0);
         textView.setTextSize(20);
         return textView;
     }
 }

运行截图：(没有改变颜色。。。)

做这个实例的时候，书上的例子是上面的代码，我一开始是想不用书上的例子，我的想法是他既然是 布局、组件都是新建，那么我应该可以事先设置好他的xml文件，等到时候用的时候，我在调用过来，但是我折腾了好久都没成功，但是我学到了怎么获取 事先布局好的Layout，但是我就不知道如何想Layout中添加组件如下：

View view = View.inflate(ExpandableListViewActivity.this, R.layout.linear_text, null);
TextView textView = (TextView) findViewById(R.id.text1);

布局是事先设置好的，textview独立xml文件或者放在Layout xml的文件中都是行不通的，可能是我想的有问题吧，有可能根本就没这个方法。

最后我放弃了，还是按照书上的例子做了下去，好气啊。先做个标记，容我去打怪升级，等我等级高了再来报仇！！！！！！！！！！！

最近工作上面的事情比较忙，所以没有多少时间学习，但是。。。。。。。。还是要坚持主动的学习下去！！！！

如果有错，请大牛们指正。 再次先谢谢了 ！