老规矩先看效果图:
这个代码很常见，网上大牛已经做过好几遍了，但是本着学习的态度，去研究了下别人写的代码。发现有好几种实现方法。最为流行的一种是使用Scroller实现滑动，然后按钮的实现有三种方法。 1. 一种是全部用java类继承一个viewgroup来动态生成listviewitem.这样灵活性很高，但是技巧性也高。 2. 一种是整个listviewitem用xml编写，然后inflate进去。这样写的好处是可以复用，，而且只需要adapter重写view， 但是按钮和内容是固定的，不能轻松的实现QQ好友那种，有时候是删除，有时候是置顶，有时候是标记什么的、多种按钮结合 3. 为此我试着把基本listviewitem和按钮xml分开写，写成2个布局，然后用一个linerlayout动态合成起来。这样在扩展的时候可以写多组按钮布局，然后动态判断合成，更容易实现多种类按钮的方法。 4.完成工程在我的github里面: 戳戳戳：https://github.com/younfor/DragListView 下面是核心源码:
package com.draglistview;import android.content.Context;import android.util.AttributeSet;import android.util.TypedValue;import android.view.MotionEvent;import android.widget.ListView;/** * * @author https://github.com/younfor * */{moveable=false;closed=true;private float mDownX,mDownY;private int mTouchPosition,oldPosition=-1;private DragDelItem mTouchView,oldView;private Context context;public DragDelListView(Context context) {super(context);init(context);}public DragDelListView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);init(context);}public DragDelListView(Context context, AttributeSet attrs) {super(context, attrs);init(context);}(Context context) {this.context=context;}(MotionEvent ev) {switch (ev.getAction()) {case MotionEvent.ACTION_DOWN://获取点击的positionmTouchPosition = pointToPosition((int) ev.getX(), (int) ev.getY());//获取点击的view (是可见范围里面的)mTouchView=(DragDelItem)getChildAt(mTouchPosition – getFirstVisiblePosition());//获取点击的地方mDownX = ev.getX();mDownY=ev.getY();//点击的是同一个或者全部初始if(oldPosition==mTouchPosition ||closed){//可以移动moveable=true;mTouchView.mDownX =(int)mDownX;}else{moveable=false;if(oldView!=null){ //旧的归位oldView.smoothCloseMenu();}}oldPosition=mTouchPosition;oldView=mTouchView;break;case MotionEvent.ACTION_MOVE://判断是否侧滑if (Math.abs(mDownX-ev.getX()) < Math.abs(mDownY-ev.getY()) * dp2px(2)) {break;}if (moveable){int dis = (int) (mTouchView.mDownX -ev.getX());//此时方向会变if(mTouchView.state==mTouchView.STATE_OPEN)dis+=mTouchView.mMenuView.getWidth();mTouchView.swipe(dis);ev.setAction(MotionEvent.ACTION_CANCEL);}break;case MotionEvent.ACTION_UP:if (moveable){if ((mTouchView.mDownX -ev.getX()) > (mTouchView.mMenuView.getWidth()/2)) {// openmTouchView.smoothOpenMenu();closed=false;} else {// closemTouchView.smoothCloseMenu();closed=true;}ev.setAction(MotionEvent.ACTION_CANCEL);}break;}return super.onTouchEvent(ev);}(int dp) {return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp,getContext().getResources().getDisplayMetrics());}}
package com.draglistview;
import android.content.Context; import android.support.v4.view.GestureDetectorCompat; import android.util.AttributeSet; import android.util.Log; import android.util.TypedValue; import android.view.GestureDetector.OnGestureListener; import android.view.GestureDetector.SimpleOnGestureListener; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import android.view.animation.Interpolator; import android.widget.AbsListView; import android.widget.FrameLayout; import android.widget.LinearLayout; import android.widget.Scroller; /** * * @author https://github.com/younfor * */ public class DragDelItem extends LinearLayout {
public static final int STATE_CLOSE = 0;public static final int STATE_OPEN = 1;private View mContentView;public View mMenuView;public int mDownX;public int state = STATE_CLOSE;public boolean isFling;private int mBaseX;private Scroller scroll;public DragDelItem(View contentView, View menuView) {super(contentView.getContext());scroll=new Scroller(getContext());mContentView = contentView;mMenuView = menuView;init();}private DragDelItem(Context context, AttributeSet attrs) {super(context, attrs);}private DragDelItem(Context context) {super(context);}private void init() {setLayoutParams(new AbsListView.LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.WRAP_CONTENT));LayoutParams contentParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);mContentView.setLayoutParams(contentParams);mMenuView.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT));addView(mContentView);addView(mMenuView);}public void swipe(int dis) {if (dis > mMenuView.getWidth()) {dis = mMenuView.getWidth();}if (dis < 0) {dis = 0;}mContentView.layout(-dis, mContentView.getTop(),mContentView.getWidth() – dis, getMeasuredHeight());mMenuView.layout(mContentView.getWidth() – dis, mMenuView.getTop(),mContentView.getWidth() + mMenuView.getWidth() – dis,mMenuView.getBottom());}@Overridepublic void computeScroll() {if (state == STATE_OPEN) {if (scroll.computeScrollOffset()) {swipe(scroll.getCurrX());postInvalidate();}} else {if (scroll.computeScrollOffset()) {swipe(mBaseX – scroll.getCurrX());postInvalidate();}}}public void smoothCloseMenu() {state = STATE_CLOSE;mBaseX = -mContentView.getLeft();scroll.startScroll(0, 0, mBaseX, 0, 350);postInvalidate();}public void smoothOpenMenu() {state = STATE_OPEN;scroll.startScroll(-mContentView.getLeft(), 0,mMenuView.getWidth()/2, 0, 350);postInvalidate();}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(widthMeasureSpec, heightMeasureSpec);mMenuView.measure(MeasureSpec.makeMeasureSpec(0,MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(getMeasuredHeight(), MeasureSpec.EXACTLY));mContentView.measure(MeasureSpec.makeMeasureSpec(0,MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(getMeasuredHeight(), MeasureSpec.EXACTLY));}@Overrideprotected void onLayout(boolean changed, int l, int t, int r, int b) {mContentView.layout(0, 0, getMeasuredWidth(),mContentView.getMeasuredHeight());mMenuView.layout(getMeasuredWidth(), 0,getMeasuredWidth() + mMenuView.getMeasuredWidth(),mContentView.getMeasuredHeight());}突然之间失去了语言。那才是真正的寂寞，
