android - RefreshableListView cannot be cast to ListView 错误(拉动刷新)

Question

我在尝试实现 Refreshable Listview 时遇到错误。是什么产生了这个错误？我可能忽略了一些东西。提前致谢。

10-10 19:01:28.815 17274-17274/? E/AndroidRuntime﹕ FATAL EXCEPTION:main java.lang.RuntimeException: Unable to start activityComponentInfo{nl.rss.foit.myapplication/nl.rss.foit.myapplication.MyActivity}:java.lang.ClassCastException: android.widget.ListView cannot be castto nl.rss.foit.myapplication.Refresh.RefreshableListView

RefreshableInterface.java

public interface RefreshableInterface {
 public void startFresh();
 public void startLoadMore();
}

RefreshableListView.Java

import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.animation.LinearInterpolator;
import android.view.animation.RotateAnimation;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.RelativeLayout;
import android.widget.TextView;

import java.text.SimpleDateFormat;
import java.util.Date;

import nl.rss.foit.myapplication.R;

public class RefreshableListView extends ListView implements OnScrollListener {

    private final int HEADER_HEIGHT = 60;
    private final int HEADER_TOP = 10;
    private final int STATE_PULL_TO_REFRESH = 0;
    private final int STATE_RELEASE_TO_UPDATE = 1;
    private int currentState;
    private ImageView arrowImage;
    private ProgressBar progressBar;
    private TextView headerTextView;
    private TextView lastUpdateDateTextView;
    private LinearLayout headerRelativeLayout;
    private RotateAnimation rotateAnimation;
    private RotateAnimation reverseRotateAnimation;
    private RefreshableInterface refreshDelegate;

    private RelativeLayout footerLayout;
    private ProgressBar footerProgressBar;
    private boolean isLoadingMore;

    private boolean isLoading;
    //private boolean isDragging;
    private float startY;
    private float deltaY;

   
    public RefreshableListView(Context context) {
        super(context);
        // TODO Auto-generated constructor stub
        init(context);
    }

    public RefreshableListView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context);
    }

    @Override
    public void onScroll(AbsListView view, int firstVisibleItem,
                         int visibleItemCount, int totalItemCount) {
        // TODO Auto-generated method stub
        Log.d("debug", "debug");
    }

    @Override
    public void onScrollStateChanged(AbsListView view, int scrollState) {
        // TODO Auto-generated method stub

    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        // TODO Auto-generated method stub
        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN:
                //isDragging = true;
                startY = ev.getY();
                break;
            case MotionEvent.ACTION_MOVE:
                if (!isLoading) {
                    deltaY = ev.getY() - startY;

                    Log.d("debug", String.valueOf(deltaY));

                    headerRelativeLayout.setPadding(
                            headerRelativeLayout.getPaddingLeft(), -1
                                    * HEADER_HEIGHT + (int) deltaY, 0,
                            headerRelativeLayout.getPaddingBottom());

                    if(headerRelativeLayout.getPaddingTop() >= HEADER_HEIGHT && currentState == STATE_PULL_TO_REFRESH) {
                        //change state
                        currentState = STATE_RELEASE_TO_UPDATE;
                        arrowImage.clearAnimation();
                        arrowImage.startAnimation(rotateAnimation);
                        headerTextView.setText(R.string.release_to_refresh);
                    } else if (headerRelativeLayout.getPaddingTop() < HEADER_HEIGHT && currentState == STATE_RELEASE_TO_UPDATE) {
                        currentState = STATE_PULL_TO_REFRESH;
                        arrowImage.clearAnimation();
                        arrowImage.startAnimation(reverseRotateAnimation);
                        headerTextView.setText(R.string.pull_to_refresh);
                    }
                }
                break;
            case MotionEvent.ACTION_UP:
                //isDragging = false;

                if (!isLoading) {
                    if (headerRelativeLayout.getPaddingTop() < HEADER_HEIGHT) {
                        // come back
                        headerRelativeLayout.setPadding(
                                headerRelativeLayout.getPaddingLeft(), -1
                                        * HEADER_HEIGHT, 0,
                                headerRelativeLayout.getPaddingBottom());
                    } else {
                        // come to HEADER_HEIGHT and start the trigger
                        headerRelativeLayout.setPadding(
                                headerRelativeLayout.getPaddingLeft(), HEADER_TOP, 0,
                                headerRelativeLayout.getPaddingBottom());

                        headerTextView.setText(R.string.loading);
                        progressBar.setVisibility(View.VISIBLE);
                        arrowImage.clearAnimation();
                        arrowImage.setVisibility(View.GONE);

                        //START LOADING
                        isLoading = true;
                        if (refreshDelegate != null) {
                            refreshDelegate.startFresh();
                        }
                    }
                }
                break;
            default:
                break;
        }

        return super.onTouchEvent(ev);
    }

    private void init(Context context) {
        headerRelativeLayout = (LinearLayout) inflate(context,
                R.layout.refresh_header_view, null);
        arrowImage = (ImageView) headerRelativeLayout
                .findViewById(R.id.head_arrowImageView);
        progressBar = (ProgressBar) headerRelativeLayout
                .findViewById(R.id.head_progressBar);
        headerTextView = (TextView) headerRelativeLayout
                .findViewById(R.id.head_tipsTextView);
        headerTextView.setText(R.string.pull_to_refresh);
        lastUpdateDateTextView = (TextView) headerRelativeLayout
                .findViewById(R.id.head_lastUpdatedDateTextView);
        lastUpdateDateTextView.setText("");
        headerRelativeLayout.setPadding(headerRelativeLayout.getPaddingLeft(),
                -1 * HEADER_HEIGHT, 0, headerRelativeLayout.getPaddingBottom());
        this.addHeaderView(headerRelativeLayout, null, false);

        footerLayout = (RelativeLayout) inflate(context, R.layout.refresh_footer_view, null);
        footerProgressBar = (ProgressBar)footerLayout.findViewById(R.id.footer_progressBar);
        footerLayout.setOnClickListener(loadMoreClickListener);
        this.addFooterView(footerLayout, null, false);
        isLoadingMore = false;

        //isDragging = false;
        currentState = STATE_PULL_TO_REFRESH;
        this.setOnScrollListener(this);

        rotateAnimation = new RotateAnimation(0, -180,
                RotateAnimation.RELATIVE_TO_SELF, 0.5f,
                RotateAnimation.RELATIVE_TO_SELF, 0.5f);
        rotateAnimation.setInterpolator(new LinearInterpolator());
        rotateAnimation.setDuration(250);
        rotateAnimation.setFillAfter(true);

        reverseRotateAnimation = new RotateAnimation(-180, 0,
                RotateAnimation.RELATIVE_TO_SELF, 0.5f,
                RotateAnimation.RELATIVE_TO_SELF, 0.5f);
        reverseRotateAnimation.setInterpolator(new LinearInterpolator());
        reverseRotateAnimation.setDuration(1);
        reverseRotateAnimation.setFillAfter(true);
    }

    private OnClickListener loadMoreClickListener = new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            if (!isLoadingMore) {
                isLoadingMore = true;
                footerProgressBar.setVisibility(View.VISIBLE);
                refreshDelegate.startLoadMore();
            }
        }
    };

    public void onRefreshComplete() {
        progressBar.setVisibility(View.GONE);
        arrowImage.setVisibility(View.VISIBLE);
        arrowImage.startAnimation(reverseRotateAnimation);

        headerRelativeLayout.setPadding(headerRelativeLayout.getPaddingLeft(),
                -1 * HEADER_HEIGHT, 0, headerRelativeLayout.getPaddingBottom());

        SimpleDateFormat format =new SimpleDateFormat("MMM dd, yyyy HH:mm:ss");
        String date=format.format(new Date());
        lastUpdateDateTextView.setText("Last Updated: " + date);

        isLoading = false;
        //isDragging = false;
    }

    public void onRefreshStart() {
        headerRelativeLayout.setPadding(headerRelativeLayout.getPaddingLeft(),
                HEADER_TOP, 0, headerRelativeLayout.getPaddingBottom());
        headerTextView.setText(R.string.loading);
        progressBar.setVisibility(View.VISIBLE);
        arrowImage.setVisibility(View.GONE);
        isLoading = true;

        if (refreshDelegate != null) {
            refreshDelegate.startFresh();
        }
    }

    public void setOnRefresh(RefreshableInterface d){
        refreshDelegate = d;
    }

    public void onLoadingMoreComplete() {
        footerProgressBar.setVisibility(View.GONE);
        isLoadingMore = false;
    }

}

布局

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <ListView
        android:id="@+id/postListView"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />


</RelativeLayout>

Answer 1

在你的布局上:

<ListView
        android:id="@+id/postListView"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />

你不应该这样做吗？

<RefreshableListView 
        android:id="@+id/postListView"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />