android----(分组、图片滑动）

整体思路：

1.要给ExpandableListView 设置适配器，那么必须先设置数据源

2.数据源，就是此处的适配品类ExpandaBleAdapter,此方法继承了BaseExpandableListAdapter ,这是ExpandableListView的子类，需要重写里面的多个方法，

数据源中，用到了自定义的View布局此时根据自己的需求，来设置线和子项的布局样式 ，

getChildView() 和 getGroupView() 方法设置自定义布局

数据源设置好，直接给ExpandableListView.setAdapter()即可实现此收缩功能

1.main_layout
<ExpandableListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/expandableListView"
android:layout_alignParentTop="true"
android:layout_alignParentStart="true"
/>

2.gruop_layout.xml child_layout也一样
<?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="wrap_content"
android:gravity="center_vertical"
>
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/icon"
android:src="@mipmap/ic_launcher"
android:maxWidth="64dp"
android:maxHeight="64dp"
android:adjustViewBounds="true"
/>

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/title"
android:text="not data"
/>
</LinearLayout>

3.核心代码：
public class MainActivity extends Activity {
private ExpandableListView listView;

//组名称
private String[] groups = {"好友","学校"};

//每一组中的内容
private String[][] childs = {{"猪猪","淡淡","默认"},{"老师","到头","呵呵"}};

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

listView = (ExpandableListView)findViewById(R.id.expandableListView);

listView.setAdapter(new MyExpandableAdapter());

//单击事件
listView.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
@Override
public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {

Toast.makeText(MainActivity.this,childs[groupPosition][childPosition],Toast.LENGTH_SHORT).show();
return  true;

}
});

}

//适配器
class  MyExpandableAdapter extends BaseExpandableListAdapter{

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

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

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

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

@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
if(convertView == null){
convertView =  getLayoutInflater().inflate(R.layout.group_layout,null);
}

ImageView icon = (ImageView) convertView.findViewById(R.id.icon);

TextView title = (TextView) convertView.findViewById(R.id.title);

title.setText(groups[groupPosition]);
// icon.setImageResource();

return convertView;
}

@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {

if(convertView == null){
convertView = getLayoutInflater().inflate(R.layout.child_layout,null);
}

ImageView icon = (ImageView) convertView.findViewById(R.id.icon);

TextView title = (TextView) convertView.findViewById(R.id.title);

title.setText(childs[groupPosition][childPosition]);

return convertView;
}

//组下的成员是否可以选中
@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
return true;
}
}

}

ImageSwitcher是Android中控制图片展示效果的一个控件，如幻灯片效果

ImageSwitcher粗略的理解就是ImageView的选择器

ImageSwither的原理：ImageSwitcher有两个子View:ImageView，当左右滑动的时候，就在这两个ImageView之间来回切换来显示图片

既然有两个子ImageView，那么我们要创建两个ImageView给ImageSwitcher。创建ImageSwitcher是通过工厂来实现的 ViewFactory

ImageSwitcher:切换图片 和文本切换一样

1.创建ImageSwitcher组件
2.将图片放于mipmap中
3.核心代码：
public class Switch extends Activity  implements ViewSwitcher.ViewFactory,View.OnTouchListener{

private ImageSwitcher imageSwitcher;

//图片数据
private  int[] images = {R.mipmap.a,R.mipmap.b,R.mipmap.c,R.mipmap.d,R.mipmap.e,R.mipmap.f};

private  int index;

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

imageSwitcher = (ImageSwitcher)findViewById(R.id.imageSwitcher2);

imageSwitcher.setOnTouchListener(this);

imageSwitcher.setFactory(this);
}

//每一张图片视图
@Override
public View makeView() {
ImageView iv = new ImageView(this);
iv.setImageResource(images[0]);
return iv;
}

float startX = 0.0f;
float endX = 0.0f;
//触屏事件
@Override
public boolean onTouch(View v, MotionEvent event) {

int action = event.getAction();//获取当前的事件动作

if(action == MotionEvent.ACTION_DOWN){
startX = event.getX();

imageSwitcher.setInAnimation(this,android.R.anim.fade_in);//图片进的动画
imageSwitcher.setInAnimation(this,android.R.anim.fade_out);//图片出的动画
return true;
}

if(action == MotionEvent.ACTION_UP){
endX = event.getX();

if(startX - endX>20){//下一张
index = index +1 <images.length?++index:0;

imageSwitcher.setInAnimation(this,android.R.anim.fade_in);//图片进的动画
imageSwitcher.setInAnimation(this,android.R.anim.fade_out);//图片出的动画
}else if(endX -startX >20){//上一张
index = index - 1>=0?--index:images.length-1;

imageSwitcher.setInAnimation(this,android.R.anim.fade_in);//图片进的动画
imageSwitcher.setInAnimation(this,android.R.anim.fade_out);//图片出的动画
}

imageSwitcher.setImageResource(images[index]);
}

return true;
}
}

flipper.xml:
<ViewFlipper
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/viewFlipper"
android:layout_alignParentTop="true"
android:layout_alignParentStart="true"
/>

//第一页
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent">

<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"

android:src="@mipmap/a" />
</LinearLayout>

//第二页
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent">

<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"

android:scaleType="centerCrop"
android:src="@mipmap/b" />
</LinearLayout>

//第三页
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent">

<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"

android:src="@mipmap/c"/>
</LinearLayout>

2.核心代码
public class flipper extends Activity {

private ViewFlipper viewFlipper;

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

viewFlipper = (ViewFlipper) findViewById(R.id.viewFlipper);
}

float startX,endX;
@Override
public boolean onTouchEvent(MotionEvent event) {

int action = event.getAction();
if(action == MotionEvent.ACTION_DOWN){
startX = event.getX();

}else if(action == MotionEvent.ACTION_UP){
if(event.getX()>startX){//向右滑动
viewFlipper.setInAnimation(this,R.anim.in_leftright);
viewFlipper.setOutAnimation(this,R.anim.out_leftright);
viewFlipper.showNext();
}else if(event.getX()<startX){//向左滑动
viewFlipper.setInAnimation(this,R.anim.in_leftright);
viewFlipper.setOutAnimation(this,R.anim.out_leftright);
viewFlipper.showPrevious();
}
}

return super.onTouchEvent(event);
}
}