XListView汇总

最新推荐文章于 2018-01-17 20:56:22 发布

原创最新推荐文章于 2018-01-17 20:56:22 发布 · 257 阅读

CC 4.0 BY-SA版权

本文介绍了一个自定义的 Android ListView 控件 XListView 的实现细节。该控件支持下拉刷新和上拉加载更多功能，并提供了相应的回调接口。文章详细解释了 XListView 的工作原理，包括如何监听触摸事件、如何计算头部和底部视图的高度等。

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图片： xlistview_arrow.png

XListView.java

import android.annotation.SuppressLint;
import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.view.animation.DecelerateInterpolator;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.Scroller;
import android.widget.TextView;

import java.text.SimpleDateFormat;
import java.util.Date;
public class XListView extends ListView implements OnScrollListener {
	private float mLastY = -1; // save event y
	private Scroller mScroller; // 用于回滚
	private OnScrollListener mScrollListener; // 回滚监听
	// 触发刷新和加载更多接口.
	private IXListViewListener mListViewListener;
	// -- 头部的View
	private XListViewHeader mHeaderView;
	// 查看头部的内容，用它计算头部高度，和隐藏它
	// 当禁用的时候刷新
	private RelativeLayout mHeaderViewContent;
	private TextView mHeaderTimeView;
	private int mHeaderViewHeight; // 头部View的高
	private boolean mEnablePullRefresh = true;
	private boolean mPullRefreshing = false; // 是否刷新.
	// -- 底部的View
	private XListViewFooter mFooterView;
	private boolean mEnablePullLoad;
	private boolean mPullLoading;
	private boolean mIsFooterReady = false;
	// 总列表项，用于检测列表视图的底部
	private int mTotalItemCount;

	// for mScroller, 滚动页眉或者页脚
	private int mScrollBack;
	private final static int SCROLLBACK_HEADER = 0;// 顶部
	private final static int SCROLLBACK_FOOTER = 1;// 下部

	private final static int SCROLL_DURATION = 400; // 滚动回时间
	private final static int PULL_LOAD_MORE_DELTA = 50; // 当大于50PX的时候，加载更多

	private final static float OFFSET_RADIO = 1.8f; // support iOS like pull
	// feature.

	/**
	 * @param context
	 */
	public XListView(Context context) {
		super(context);
		initWithContext(context);
	}

	public XListView(Context context, AttributeSet attrs) {
		super(context, attrs);
		initWithContext(context);
	}

	public XListView(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
		initWithContext(context);
	}

	private void initWithContext(Context context) {
		mScroller = new Scroller(context, new DecelerateInterpolator());
		// XListView need the scroll event, and it will dispatch the event to
		// user's listener (as a proxy).
		super.setOnScrollListener(this);

		// 初始化头部View
		mHeaderView = new XListViewHeader(context);
		mHeaderViewContent = (RelativeLayout) mHeaderView
				.findViewById(R.id.xlistview_header_content);
		mHeaderTimeView = (TextView) mHeaderView
				.findViewById(R.id.xlistview_header_time);
		addHeaderView(mHeaderView);// 把头部这个视图添加进去

		// 初始化底部的View
		mFooterView = new XListViewFooter(context);

		// 初始化头部高度
		mHeaderView.getViewTreeObserver().addOnGlobalLayoutListener(
				new OnGlobalLayoutListener() {
					@Override
					public void onGlobalLayout() {
						mHeaderViewHeight = mHeaderViewContent.getHeight();
						getViewTreeObserver()
								.removeGlobalOnLayoutListener(this);
					}
				});
	}

	@Override
	public void setAdapter(ListAdapter adapter) {
		// 确定XListViewFooter是最后底部的View, 并且只有一次
		if (mIsFooterReady == false) {
			mIsFooterReady = true;
			addFooterView(mFooterView);
		}
		super.setAdapter(adapter);
	}

	/**
	 * 启用或禁用下拉刷新功能.
	 *
	 * @param enable
	 */
	public void setPullRefreshEnable(boolean enable) {
		mEnablePullRefresh = enable;
		if (!mEnablePullRefresh) { // 禁用,隐藏内容
			mHeaderViewContent.setVisibility(View.INVISIBLE);// 如果为false则隐藏下拉刷新功能
		} else {
			mHeaderViewContent.setVisibility(View.VISIBLE);// 否则就显示下拉刷新功能
		}
	}

	/**
	 * 启用或禁用加载更多的功能.
	 *
	 * @param enable
	 */
	public void setPullLoadEnable(boolean enable) {
		mEnablePullLoad = enable;
		if (!mEnablePullLoad) {
			mFooterView.hide();// 隐藏
			mFooterView.setOnClickListener(null);
		} else {
			mPullLoading = false;
			mFooterView.show();// 显示
			mFooterView.setState( XListViewFooter.STATE_NORMAL);
			// both "上拉" 和 "点击" 将调用加载更多.
			mFooterView.setOnClickListener(new OnClickListener() {
				@Override
				public void onClick(View v) {
					startLoadMore();
				}
			});
		}
	}

	/**
	 * 停止刷新, 重置头视图.
	 */
	public void stopRefresh() {
		if (mPullRefreshing == true) {
			mPullRefreshing = false;
			resetHeaderHeight();
		}
	}

	/**
	 * stop load more, reset footer view.
	 */
	public void stopLoadMore() {
		if (mPullLoading == true) {
			mPullLoading = false;
			mFooterView.setState( XListViewFooter.STATE_NORMAL);
		}
	}

	/**
	 * 設置最後一次刷新時間
	 *
	 * @param time
	 */
	@SuppressLint("SimpleDateFormat")
	public void setRefreshTime(String time) {
		SimpleDateFormat   formatter   =   new   SimpleDateFormat   ("yyyy年MM月dd日   HH:mm:ss     ");
		Date   curDate   =   new   Date(System.currentTimeMillis());
		//获取当前时间
		String   str   =   formatter.format(curDate);
		mHeaderTimeView.setText(str);
	}

	private void invokeOnScrolling() {
		if (mScrollListener instanceof OnXScrollListener) {
			OnXScrollListener l = (OnXScrollListener) mScrollListener;
			l.onXScrolling(this);
		}
	}

	private void updateHeaderHeight(float delta) {
		mHeaderView.setVisiableHeight((int) delta
				+ mHeaderView.getVisiableHeight());
		if (mEnablePullRefresh && !mPullRefreshing) { // 未处于刷新状态，更新箭头
			if (mHeaderView.getVisiableHeight() > mHeaderViewHeight) {
				mHeaderView.setState( XListViewHeader.STATE_READY);
			} else {
				mHeaderView.setState( XListViewHeader.STATE_NORMAL);
			}
		}
		setSelection(0); // scroll to top each time
	}

	/**
	 * 重置头视图的高度
	 */
	private void resetHeaderHeight() {
		int height = mHeaderView.getVisiableHeight();
		if (height == 0) // 不显示.
			return;
		// 不显示刷新和标题的时候，什么都不显示
		if (mPullRefreshing && height <= mHeaderViewHeight) {
			return;
		}
		int finalHeight = 0; // 默认：滚动回头.
		// 当滚动回显示所有头标题时候，刷新
		if (mPullRefreshing && height > mHeaderViewHeight) {
			finalHeight = mHeaderViewHeight;
		}
		mScrollBack = SCROLLBACK_HEADER;
		mScroller.startScroll(0, height, 0, finalHeight - height,
				SCROLL_DURATION);
		// 触发刷新
		invalidate();
	}

	// 改变底部视图高度
	private void updateFooterHeight(float delta) {
		int height = mFooterView.getBottomMargin() + (int) delta;
		if (mEnablePullLoad && !mPullLoading) {
			if (height > PULL_LOAD_MORE_DELTA) { // 高度足以调用加载更多
				mFooterView.setState( XListViewFooter.STATE_READY);
			} else {
				mFooterView.setState( XListViewFooter.STATE_NORMAL);
			}
		}
		mFooterView.setBottomMargin(height);

		// setSelection(mTotalItemCount - 1); // scroll to bottom
	}

	private void resetFooterHeight() {
		int bottomMargin = mFooterView.getBottomMargin();
		if (bottomMargin > 0) {
			mScrollBack = SCROLLBACK_FOOTER;
			mScroller.startScroll(0, bottomMargin, 0, -bottomMargin,
					SCROLL_DURATION);
			invalidate();
		}
	}

	// 开始加载更多
	private void startLoadMore() {
		mPullLoading = true;
		mFooterView.setState( XListViewFooter.STATE_LOADING);
		if (mListViewListener != null) {
			mListViewListener.onLoadMore();
		}
	}

	// 触发事件
	@Override
	public boolean onTouchEvent(MotionEvent ev) {
		if (mLastY == -1) {
			mLastY = ev.getRawY();
		}

		switch (ev.getAction()) {
			case MotionEvent.ACTION_DOWN:
				mLastY = ev.getRawY();
				break;
			case MotionEvent.ACTION_MOVE:
				final float deltaY = ev.getRawY() - mLastY;
				mLastY = ev.getRawY();
				System.out.println("数据监测：" + getFirstVisiblePosition() + "---->"
						+ getLastVisiblePosition());
				if (getFirstVisiblePosition() == 0
						&& (mHeaderView.getVisiableHeight() > 0 || deltaY > 0)) {
					// 第一项显示,标题显示或拉下来.
					updateHeaderHeight(deltaY / OFFSET_RADIO);
					invokeOnScrolling();
				} else if (getLastVisiblePosition() == mTotalItemCount - 1
						&& (mFooterView.getBottomMargin() > 0 || deltaY < 0)) {
					// 最后一页，已停止或者想拉起
					updateFooterHeight(-deltaY / OFFSET_RADIO);
				}
				break;
			default:
				mLastY = -1; // 重置
				if (getFirstVisiblePosition() == 0) {
					// 调用刷新,如果头部视图高度大于设定高度。
					if (mEnablePullRefresh
							&& mHeaderView.getVisiableHeight() > mHeaderViewHeight) {
						mPullRefreshing = true;// 那么刷新
						mHeaderView.setState( XListViewHeader.STATE_REFRESHING);
						if (mListViewListener != null) {
							mListViewListener.onRefresh();
						}
					}
					resetHeaderHeight();// 刷新完毕，重置头部高度，也就是返回上不
				}
				if (getLastVisiblePosition() == mTotalItemCount - 1) {
					// 调用加载更多.
					if (mEnablePullLoad
							&& mFooterView.getBottomMargin() > PULL_LOAD_MORE_DELTA) {
						startLoadMore();// 如果底部视图高度大于可以加载高度，那么就开始加载
					}
					resetFooterHeight();// 重置加载更多视图高度
				}
				break;
		}
		return super.onTouchEvent(ev);
	}

	@Override
	public void computeScroll() {
		if (mScroller.computeScrollOffset()) {
			if (mScrollBack == SCROLLBACK_HEADER) {
				mHeaderView.setVisiableHeight(mScroller.getCurrY());
			} else {
				mFooterView.setBottomMargin(mScroller.getCurrY());
			}
			postInvalidate();
			invokeOnScrolling();
		}
		super.computeScroll();
	}

	@Override
	public void setOnScrollListener(OnScrollListener l) {
		mScrollListener = l;
	}

	@Override
	public void onScrollStateChanged(AbsListView view, int scrollState) {
		if (mScrollListener != null) {
			mScrollListener.onScrollStateChanged(view, scrollState);
		}
	}

	@Override
	public void onScroll(AbsListView view, int firstVisibleItem,
						 int visibleItemCount, int totalItemCount) {
		// 发送到用户的监听器
		mTotalItemCount = totalItemCount;
		if (mScrollListener != null) {
			mScrollListener.onScroll(view, firstVisibleItem, visibleItemCount,
					totalItemCount);
		}
	}

	public void setXListViewListener(IXListViewListener l) {
		mListViewListener = l;
	}




	/**
	 * 你可以监听到列表视图，OnScrollListener 或者这个. 他将会被调用 , 当头部或底部触发的时候
	 */
	public interface OnXScrollListener extends OnScrollListener {
		public void onXScrolling(View view);
	}

	/**
	 * 实现这个接口来刷新/负载更多的事件
	 */
	public interface IXListViewListener {
		public void onRefresh();

		public void onLoadMore();
	}
}

XListViewFooter.java

import android.content.Context;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.TextView;

public class XListViewFooter extends LinearLayout {
	public final static int STATE_NORMAL = 0;
	public final static int STATE_READY = 1;
	public final static int STATE_LOADING = 2;

	private Context mContext;

	private View mContentView;
	private View mProgressBar;
	private TextView mHintView;

	public XListViewFooter(Context context) {
		super(context);
		initView(context);
	}

	public XListViewFooter(Context context, AttributeSet attrs) {
		super(context, attrs);
		initView(context);
	}

	public void setState(int state) {
		mHintView.setVisibility(View.INVISIBLE);// 开始底部控件都隐藏
		mProgressBar.setVisibility(View.INVISIBLE);
		mHintView.setVisibility(View.INVISIBLE);
		if (state == STATE_READY) {// 如果是第一页状态，那么“查看更多”显示
			mHintView.setVisibility(View.VISIBLE);
			mHintView.setText(R.string.xlistview_footer_hint_ready);// 松开显示更多
		} else if (state == STATE_LOADING) {// 当加载的时候
			mProgressBar.setVisibility(View.VISIBLE);// 加载进度条显示
		} else {
			mHintView.setVisibility(View.VISIBLE);
			mHintView.setText(R.string.xlistview_footer_hint_normal);// 查看更多
		}
	}

	public void setBottomMargin(int height) {
		if (height < 0)
			return;
		LayoutParams lp = (LayoutParams) mContentView
				.getLayoutParams();
		lp.bottomMargin = height;
		mContentView.setLayoutParams(lp);
	}

	public int getBottomMargin() {
		LayoutParams lp = (LayoutParams) mContentView
				.getLayoutParams();
		return lp.bottomMargin;
	}

	/**
	 * normal status
	 */
	public void normal() {
		mHintView.setVisibility(View.VISIBLE);
		mProgressBar.setVisibility(View.GONE);
	}

	/**
	 * loading status
	 */
	public void loading() {
		mHintView.setVisibility(View.GONE);
		mProgressBar.setVisibility(View.VISIBLE);
	}

	/**
	 * 当禁用拉加载更多隐藏底部视图
	 */
	public void hide() {
		LayoutParams lp = (LayoutParams) mContentView
				.getLayoutParams();
		lp.height = 0;
		mContentView.setLayoutParams(lp);
	}

	/**
	 * 显示底部视图
	 */
	public void show() {
		LayoutParams lp = (LayoutParams) mContentView
				.getLayoutParams();
		lp.height = LayoutParams.WRAP_CONTENT;
		mContentView.setLayoutParams(lp);
	}

	private void initView(Context context) {
		mContext = context;
		LinearLayout moreView = (LinearLayout) LayoutInflater.from(mContext)
				.inflate(R.layout.xlistview_footer, null);
		addView(moreView);
		moreView.setLayoutParams(new LayoutParams(
				LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT));

		mContentView = moreView.findViewById(R.id.xlistview_footer_content);
		mProgressBar = moreView.findViewById(R.id.xlistview_footer_progressbar);
		mHintView = (TextView) moreView
				.findViewById(R.id.xlistview_footer_hint_textview);
	}

}

XListViewHeader.java

import android.content.Context;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.RotateAnimation;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ProgressBar;
import android.widget.TextView;

public class XListViewHeader extends LinearLayout {
	private LinearLayout mContainer;
	private ImageView mArrowImageView;
	private ProgressBar mProgressBar;
	private TextView mHintTextView;
	private int mState = STATE_NORMAL;// 初始状态

	private Animation mRotateUpAnim;
	private Animation mRotateDownAnim;

	private final int ROTATE_ANIM_DURATION = 180;

	public final static int STATE_NORMAL = 0;
	public final static int STATE_READY = 1;
	public final static int STATE_REFRESHING = 2;

	public XListViewHeader(Context context) {
		super(context);
		initView(context);
	}

	/**
	 * @param context
	 * @param attrs
	 */
	public XListViewHeader(Context context, AttributeSet attrs) {
		super(context, attrs);
		initView(context);
	}

	private void initView(Context context) {
		// 初始情况，设置下拉刷新view高度为0
		LayoutParams lp = new LayoutParams(
				LayoutParams.FILL_PARENT, 0);
		// 时间TextView
		mContainer = (LinearLayout) LayoutInflater.from(context).inflate(
				R.layout.xlistview_header, null);
		addView(mContainer, lp);
		setGravity(Gravity.BOTTOM);
		// 找到头部页面里的控件
		mArrowImageView = (ImageView) findViewById(R.id.xlistview_header_arrow);
		mHintTextView = (TextView) findViewById(R.id.xlistview_header_hint_textview);
		mProgressBar = (ProgressBar) findViewById(R.id.xlistview_header_progressbar);

		mRotateUpAnim = new RotateAnimation(0.0f, -180.0f,
				Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF,
				0.5f);
		mRotateUpAnim.setDuration(ROTATE_ANIM_DURATION);
		mRotateUpAnim.setFillAfter(true);
		mRotateDownAnim = new RotateAnimation(-180.0f, 0.0f,
				Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF,
				0.5f);
		mRotateDownAnim.setDuration(ROTATE_ANIM_DURATION);
		mRotateDownAnim.setFillAfter(true);
	}

	// 设置状态
	public void setState(int state) {
		if (state == mState)
			return;

		if (state == STATE_REFRESHING) { // 显示进度
			mArrowImageView.clearAnimation();
			mArrowImageView.setVisibility(View.INVISIBLE);// 不显示图片
			mProgressBar.setVisibility(View.VISIBLE);// 显示进度条
		} else { // 显示箭头图片
			mArrowImageView.setVisibility(View.VISIBLE);
			mProgressBar.setVisibility(View.INVISIBLE);
		}

		switch (state) {
			case STATE_NORMAL:
				if (mState == STATE_READY) {// 当状态时准备的时候，显示动画
					mArrowImageView.startAnimation(mRotateDownAnim);
				}
				if (mState == STATE_REFRESHING) {// 当状态显示进度条的时候，清除动画
					mArrowImageView.clearAnimation();
				}
				mHintTextView.setText(R.string.xlistview_header_hint_normal);// 文字提示：下拉刷新
				break;
			case STATE_READY:
				if (mState != STATE_READY) {
					mArrowImageView.clearAnimation();
					mArrowImageView.startAnimation(mRotateUpAnim);
					mHintTextView.setText(R.string.xlistview_header_hint_ready);// 松开刷新数据
				}
				break;
			case STATE_REFRESHING:
				mHintTextView.setText(R.string.xlistview_header_hint_loading);
				break;
			default:
		}

		mState = state;
	}

	public void setVisiableHeight(int height) {
		if (height < 0)
			height = 0;
		LayoutParams lp = (LayoutParams) mContainer
				.getLayoutParams();
		lp.height = height;
		mContainer.setLayoutParams(lp);
	}

	public int getVisiableHeight() {
		return mContainer.getHeight();
	}

}

xlistview_footer.xml

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

    <RelativeLayout
        android:id="@+id/xlistview_footer_content"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:padding="10dp" >

        <ProgressBar
            android:id="@+id/xlistview_footer_progressbar"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:visibility="invisible" />

        <TextView
            android:id="@+id/xlistview_footer_hint_textview"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:text="@string/xlistview_footer_hint_normal" />
    </RelativeLayout>

</LinearLayout>

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

    <RelativeLayout
        android:id="@+id/xlistview_header_content"
        android:layout_width="fill_parent"
        android:layout_height="60dp" >

        <LinearLayout
            android:id="@+id/xlistview_header_text"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:gravity="center"
            android:orientation="vertical" >

            <TextView
                android:id="@+id/xlistview_header_hint_textview"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/xlistview_header_hint_normal" />

            <LinearLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="3dp" >

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/xlistview_header_last_time"
                    android:textSize="12sp" />

                <TextView
                    android:id="@+id/xlistview_header_time"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:textSize="12sp" />
            </LinearLayout>
        </LinearLayout>

        <ImageView
            android:id="@+id/xlistview_header_arrow"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignLeft="@id/xlistview_header_text"
            android:layout_centerVertical="true"
            android:layout_marginLeft="-35dp"
            android:src="@mipmap/ic_launcher" />

        <ProgressBar
            android:id="@+id/xlistview_header_progressbar"
            android:layout_width="30dp"
            android:layout_height="30dp"
            android:layout_alignLeft="@id/xlistview_header_text"
            android:layout_centerVertical="true"
            android:layout_marginLeft="-40dp"
            android:visibility="invisible" />
    </RelativeLayout>

</LinearLayout>
strings.xml  加
 <string name="xlistview_header_hint_normal">下拉刷新</string>
    <string name="xlistview_header_hint_ready">松开刷新数据</string>
    <string name="xlistview_header_hint_loading">正在加载...</string>
    <string name="xlistview_header_last_time">上次更新时间：</string>
    <string name="xlistview_footer_hint_normal">查看更多</string>
    <string name="xlistview_footer_hint_ready">松开载入更多</string>