我们做listview左右滑动操作时，一般中情况下，都是像QQ那样，左滑弹出操作菜单（删除、编辑），然后选择菜单操作； 这样的效果不可谓不好，算是非常经典。 另外，有少数的APP，尤其是任务管理类的APP，更加注重listview的操作交互，例如ToDoList及滴答清单，这两个APP对任务的操作是直接通过滑动列表进行操作的；效果图如下：
gtihub上有一个开源项目，已经很好的实现了对该效果：https://github.com/wdullaer/SwipeActionAdapter ； 此处，就简单下介绍该开源项目。
1. 使用Android Studio新建项目导入该开源库：
导入该库，可以在build.gradle中添加：
dependencies {
compile 'com.wdullaer:swipeactionadapter:2.0.0'
}
当然，我更建议直接把该项目的library直接导入到项目中，这样会更加方便对代码进行修改。
2. 首先，设置ListView显示：
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Create an Adapter for your content
String[] content = new String[20];
for (int i=0;i<20;i++) content[i] = "Row "+(i+1);
ArrayAdapter<String> stringAdapter = new ArrayAdapter<String>(
this,
R.layout.row_bg,
R.id.text,
new ArrayList<String>(Arrays.asList(content))
);
// Wrap your content in a SwipeActionAdapter
mAdapter = new SwipeActionAdapter(stringAdapter);
// Pass a reference of your ListView to the SwipeActionAdapter
mAdapter.setListView(getListView());
// Set the SwipeActionAdapter as the Adapter for your ListView
setListAdapter(mAdapter);
} 上面的代码很简单，只是比正常使用ListView多了一步：SwipeActionAdapter mAdapter = new SwipeActionAdapter(stringAdapter); 就是在普通Adapter的基础上包裹上一层SwipeActionAdapter。
3. 为ListView的Item添加滑动时的背景色
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Create an Adapter for your content
String[] content = new String[20];
for (int i=0;i<20;i++) content[i] = "Row "+(i+1);
ArrayAdapter<String> stringAdapter = new ArrayAdapter<String>(
this,
R.layout.row_bg,
R.id.text,
new ArrayList<String>(Arrays.asList(content))
);
// Wrap your content in a SwipeActionAdapter
mAdapter = new SwipeActionAdapter(stringAdapter);
// Pass a reference of your ListView to the SwipeActionAdapter
mAdapter.setListView(getListView());
// Set the SwipeActionAdapter as the Adapter for your ListView
setListAdapter(mAdapter);
// Set backgrounds for the swipe directions
mAdapter.addBackground(SwipeDirection.DIRECTION_FAR_LEFT,R.layout.row_bg_left_far)
.addBackground(SwipeDirection.DIRECTION_NORMAL_LEFT,R.layout.row_bg_left)
.addBackground(SwipeDirection.DIRECTION_FAR_RIGHT,R.layout.row_bg_right_far)
.addBackground(SwipeDirection.DIRECTION_NORMAL_RIGHT,R.layout.row_bg_right);
}
上述代码最后，既是添加背景的代码，代码很明了，在为不同的滑动过程，添加不同的背景，该背景其实就是一个布局，例如row_bg_left_far.xml文件：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="?android:listPreferredItemHeight"
android:background="@android:color/holo_blue_bright">
</LinearLayout>
此处，可以查看下SwipeDirection.java类源码:
public enum SwipeDirection {
// Constants
DIRECTION_NORMAL_LEFT,
DIRECTION_FAR_LEFT,
DIRECTION_NORMAL_RIGHT,
DIRECTION_FAR_RIGHT,
DIRECTION_NEUTRAL;
@NonNull
public static List<SwipeDirection> getAllDirections(){
return Arrays.asList(
DIRECTION_FAR_LEFT,
DIRECTION_FAR_RIGHT,
DIRECTION_NEUTRAL,
DIRECTION_NORMAL_LEFT,
DIRECTION_NORMAL_RIGHT
);
}
public boolean isLeft() {
return this.equals(DIRECTION_NORMAL_LEFT) || this.equals(DIRECTION_FAR_LEFT);
}
public boolean isRight() {
return this.equals(DIRECTION_NORMAL_RIGHT) || this.equals(DIRECTION_FAR_RIGHT);
}
}
我们可以看出，主要的操作有四个： DIRECTION_NORMAL_LEFT（左滑一小段距离）,DIRECTION_FAR_LEFT（左滑较长距离）, DIRECTION_NORMAL_RIGHT（右滑一小段距离）,DIRECTION_FAR_RIGHT（右滑较长距离）。
4. 添加ListView左右滑动监听：
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Create an Adapter for your content
String[] content = new String[20];
for (int i=0;i<20;i++) content[i] = "Row "+(i+1);
ArrayAdapter<String> stringAdapter = new ArrayAdapter<String>(
this,
R.layout.row_bg,
R.id.text,
new ArrayList<String>(Arrays.asList(content))
);
// Wrap your content in a SwipeActionAdapter
mAdapter = new SwipeActionAdapter(stringAdapter);
// Pass a reference of your ListView to the SwipeActionAdapter
mAdapter.setListView(getListView());
// Set the SwipeActionAdapter as the Adapter for your ListView
setListAdapter(mAdapter);
// Set backgrounds for the swipe directions
mAdapter.addBackground(SwipeDirection.DIRECTION_FAR_LEFT,R.layout.row_bg_left_far)
.addBackground(SwipeDirection.DIRECTION_NORMAL_LEFT,R.layout.row_bg_left)
.addBackground(SwipeDirection.DIRECTION_FAR_RIGHT,R.layout.row_bg_right_far)
.addBackground(SwipeDirection.DIRECTION_NORMAL_RIGHT,R.layout.row_bg_right);
// Listen to swipes
mAdapter.setSwipeActionListener(new SwipeActionListener(){
@Override
public boolean hasActions(int position, SwipeDirection direction){
if(direction.isLeft()) return true; // Change this to false to disable left swipes
if(direction.isRight()) return true;
return false;
}
@Override
public boolean shouldDismiss(int position, SwipeDirection direction){
// Only dismiss an item when swiping normal left
return direction == SwipeDirection.DIRECTION_NORMAL_LEFT;
}
@Override
public void onSwipe(int[] positionList, SwipeDirection[] directionList){
for(int i=0;i<positionList.length;i++) {
int direction = directionList[i];
int position = positionList[i];
String dir = "";
switch (direction) {
case SwipeDirection.DIRECTION_FAR_LEFT:
dir = "Far left";
break;
case SwipeDirection.DIRECTION_NORMAL_LEFT:
dir = "Left";
break;
case SwipeDirection.DIRECTION_FAR_RIGHT:
dir = "Far right";
break;
case SwipeDirection.DIRECTION_NORMAL_RIGHT:
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Test Dialog").setMessage("You swiped right").create().show();
dir = "Right";
break;
}
Toast.makeText(
this,
dir + " swipe Action triggered on " + mAdapter.getItem(position),
Toast.LENGTH_SHORT
).show();
mAdapter.notifyDataSetChanged();
}
}
});
}
· public boolean hasActions(int position, SwipeDirection direction) ： 该方法主要判断滑动方向：左滑还是右滑。
· public boolean shouldDismiss(int position, SwipeDirection direction)：该方法主要判断list item滑动后是否有消失的动画。
· public void onSwipe(int[] positionList, SwipeDirection[] directionList)： 主要在该方法中处理滑动逻辑。
以上，就是SwipeActionAdapter的基本使用方式，相信善用该库，一定会给APP增添几分色彩，提高用户体验！