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Android 自定义ListView实现左划删除

2017-04-05 17:31 225 查看

项目中遇到一个要求在listview 列表中左划item 显示删除按钮(仿QQ获取微信左划删除)

步骤1.自定义listview 本人用到了万能刷新所以多了一步实现Pullable接口如果没有需求可以删除

/**

* listview 左划删除

* */

public class SwipeListView extends ListView implements Pullable{

private Boolean mIsHorizontal;
private View mPreItemView;
private View mCurrentItemView;
private float mFirstX;
private float mFirstY;
private int mRightViewWidth;
private final int mDuration = 100;
private final int mDurationStep = 10;
private boolean mIsShown;

public SwipeListView(Context context) {
this(context, null);
}

public SwipeListView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}

public SwipeListView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);

TypedArray mTypedArray = context.obtainStyledAttributes(attrs,R.styleable.swipelistviewstyle);
//获取自定义属性和默认值
mRightViewWidth = (int) mTypedArray.getDimension(R.styleable.swipelistviewstyle_right_width, 200);
mTypedArray.recycle();
}

/**
* return true, deliver to listView. return false, deliver to child. if
* move, return true
*/

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
float lastX = ev.getX();
float lastY = ev.getY();
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
mIsHorizontal = null;
mFirstX = lastX;
mFirstY = lastY;
int motionPosition = pointToPosition((int) mFirstX, (int) mFirstY);

if (motionPosition >= 0) {
View currentItemView = getChildAt(motionPosition
- getFirstVisiblePosition());
mPreItemView = mCurrentItemView;
mCurrentItemView = currentItemView;
}
break;

case MotionEvent.ACTION_MOVE:
float dx = lastX - mFirstX;
float dy = lastY - mFirstY;

if (Math.abs(dx) >= 5 && Math.abs(dy) >= 5) {
return true;
}
break;

case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
if (mIsShown&& (mPreItemView != mCurrentItemView || isHitCurItemLeft(lastX))) {
/**
* 情况一：
* 
* 一个Item的右边布局已经显示，
* 
* 这时候点击任意一个item, 那么那个右边布局显示的item隐藏其右边布局
*/
hiddenRight(mPreItemView);
}
break;
}

return super.onInterceptTouchEvent(ev);
}

private boolean isHitCurItemLeft(float x) {
return x < getWidth() - mRightViewWidth;
}

/**
* @param dx
* @param dy
* @return judge if can judge scroll direction
*/

private boolean judgeScrollDirection(float dx, float dy) {
boolean canJudge = true;

if (Math.abs(dx) > 30 && Math.abs(dx) > 2 * Math.abs(dy)) {
mIsHorizontal = true;
} else if (Math.abs(dy) > 30 && Math.abs(dy) > 2 * Math.abs(dx)) {
mIsHorizontal = false;
} else {
canJudge = false;
}

return canJudge;
}

/**
* return false, can't move any direction. return true, cant't move
* vertical, can move horizontal. return super.onTouchEvent(ev), can move
* both.
*/

@Override
public boolean onTouchEvent(MotionEvent ev) {
float lastX = ev.getX();
float lastY = ev.getY();

switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
break;

case MotionEvent.ACTION_MOVE:
float dx = lastX - mFirstX;
float dy = lastY - mFirstY;

if (mIsHorizontal == null) {
if (!judgeScrollDirection(dx, dy)) {
break;
}
}

if (mIsHorizontal) {
if (mIsShown && mPreItemView != mCurrentItemView) {
/**
* 情况二：
* 
* 一个Item的右边布局已经显示，
* 
* 这时候左右滑动另外一个item,那个右边布局显示的item隐藏其右边布局
* 
* 向左滑动只触发该情况，向右滑动还会触发情况五
*/
hiddenRight(mPreItemView);
}

if (mIsShown && mPreItemView == mCurrentItemView) {
dx = dx - mRightViewWidth;
}

// can't move beyond boundary
if (dx < 0 && dx > -mRightViewWidth) {
mCurrentItemView.scrollTo((int) (-dx), 0);
}

return true;
} else {
if (mIsShown) {
/**
* 情况三：
* 
* 一个Item的右边布局已经显示，
* 
* 这时候上下滚动ListView,那么那个右边布局显示的item隐藏其右边布局
*/
hiddenRight(mPreItemView);
}
}

break;

case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
clearPressedState();
if (mIsShown) {
/**
* 情况四：
* 
* 一个Item的右边布局已经显示，
* 
* 这时候左右滑动当前一个item,那个右边布局显示的item隐藏其右边布局
*/
hiddenRight(mPreItemView);
}

if (mIsHorizontal != null && mIsHorizontal) {
if (mFirstX - lastX > mRightViewWidth / 2) {
showRight(mCurrentItemView);
} else {
/**
* 情况五：
* 
* 向右滑动一个item,且滑动的距离超过了右边View的宽度的一半，隐藏之。
*/
hiddenRight(mCurrentItemView);
}

return true;
}

break;
}

return super.onTouchEvent(ev);
}

private void clearPressedState() {
if(mCurrentItemView!=null){
mCurrentItemView.setPressed(false);
}
setPressed(false);
refreshDrawableState();
}

private void showRight(View view) {
Message msg = new MoveHandler().obtainMessage();
msg.obj = view;
msg.arg1 = view.getScrollX();
msg.arg2 = mRightViewWidth;
msg.sendToTarget();

mIsShown = true;
}

private void hiddenRight(View view) {
if (mCurrentItemView == null) {
return;
}
Message msg = new MoveHandler().obtainMessage();//
msg.obj = view;
msg.arg1 = view.getScrollX();
msg.arg2 = 0;

msg.sendToTarget();

mIsShown = false;
}

/**
* show or hide right layout animation
*/
@SuppressLint("HandlerLeak")
class MoveHandler extends Handler {
int stepX = 0;

int fromX;

int toX;

View view;

private boolean mIsInAnimation = false;

private void animatioOver() {
mIsInAnimation = false;
stepX = 0;
}

@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
if (stepX == 0) {
if (mIsInAnimation) {
return;
}
mIsInAnimation = true;
view = (View) msg.obj;
fromX = msg.arg1;
toX = msg.arg2;
stepX = (int) ((toX - fromX) * mDurationStep * 1.0 / mDuration);
if (stepX < 0 && stepX > -1) {
stepX = -1;
} else if (stepX > 0 && stepX < 1) {
stepX = 1;
}
if (Math.abs(toX - fromX) < 10) {
view.scrollTo(toX, 0);
animatioOver();
return;
}
}

fromX += stepX;
boolean isLastStep = (stepX > 0 && fromX > toX)
|| (stepX < 0 && fromX < toX);
if (isLastStep) {
fromX = toX;
}

view.scrollTo(fromX, 0);
invalidate();

if (!isLastStep) {
this.sendEmptyMessageDelayed(0, mDurationStep);
} else {
animatioOver();
}
}
}

public int getRightViewWidth() {
return mRightViewWidth;
}

public void setRightViewWidth(int mRightViewWidth) {
this.mRightViewWidth = mRightViewWidth;
}

@Override
public boolean canPullDown() {//下拉刷新
if(getCount()==0){
return false;
}else if(getFirstVisiblePosition()==0&&getChildAt(0).getTop()>=0){//滑到ListView的顶部了
return true;
}else{
return false;
}
}

@Override
public boolean canPullUp() {//上拉更多
if(getCount()==0){
return false;
}else if(getLastVisiblePosition()==(getCount()-1)){//滑到底部了
if(getChildAt(getLastVisiblePosition()-getFirstVisiblePosition())!=null&&getChildAt(getLastVisiblePosition()-getFirstVisiblePosition()).getBottom() <= getMeasuredHeight()){
return true;
}else{
return false;
}
}else{
return false;
}
}

}

2.adapter 中

private onRightItemClickListener mListener=null;

public void setOnRightItemClickListener(onRightItemClickListener listener){

mListener=listener;

}

vh.item_left=(LinearLayout) arg1.findViewById(R.id.positionmanagementlistview_leftlayout);

vh.item_right=(LinearLayout) arg1.findViewById(R.id.positionmanagementlistview_rightlayout);

//动态获取left 和right的宽度

LinearLayout.LayoutParams lp1=new LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.MATCH_PARENT);

vh.item_left.setLayoutParams(lp1);

LinearLayout.LayoutParams lp2=new LayoutParams(mRightWidth, LayoutParams.MATCH_PARENT);

vh.item_right.setLayoutParams(lp2);

vh.item_right.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
if(mListener!=null) {

mListener.onRightItemClick(arg0, pp);

}
}

});

3.activity页面中

//左划删除
adapter.setOnRightItemClickListener(new onRightItemClickListener() {

@Override
public void onRightItemClick(View v, int position) {
String name=list.get(position).getTitle();
toast.showToast("删除"+name);
}

});

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标签： android 左划删除 Listview左划删除左划删除 android 删除 Listview删除

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