Android常用控件之下拉刷新Wifi列表

界面

關鍵代碼

下拉列表類

package com.example.dropdownrefresh.ui;

import java.text.SimpleDateFormat;

import java.util.Date;

import com.example.dropdownrefresh.R;

import android.content.Context;

import android.util.AttributeSet;

import android.util.Log;

import android.view.LayoutInflater;

import android.view.MotionEvent;

import android.view.View;

import android.view.ViewGroup;

import android.view.animation.LinearInterpolator;

import android.view.animation.RotateAnimation;

import android.widget.AbsListView;

import android.widget.AbsListView.OnScrollListener;

import android.widget.BaseAdapter;

import android.widget.ImageView;

import android.widget.LinearLayout;

import android.widget.ListView;

import android.widget.ProgressBar;

import android.widget.TextView;

/**

* 下拉列表類

* @author Administrator

*

*/

public class DropdownListView extends ListView implements OnScrollListener {

private static final String TAG = listview;

private final static int RELEASE_To_REFRESH = 0;

private final static int PULL_To_REFRESH = 1;

private final static int REFRESHING = 2;

private final static int DONE = 3;

private final static int LOADING = 4;

// 實際的padding的距離與界面上偏移距離的比例

private final static int RATIO = 3;

private LayoutInflater inflater;

private LinearLayout headView;

private TextView tipsTextview;

private TextView lastUpdatedTextView;

private ImageView arrowImageView;

private ProgressBar progressBar;

private RotateAnimation animation;

private RotateAnimation reverseAnimation;

// 用于保證startY的值在一個完整的touch事件中只被記錄一次

private boolean isRecored;

private int headContentWidth;

private int headContentHeight;

private int startY;

private int firstItemIndex;

private int state;

private boolean isBack;

private OnRefreshListener refreshListener;

private boolean isRefreshable;

public DropdownListView(Context context) {

super(context);

// TODO Auto-generated constructor stub

init(context);

}

public DropdownListView(Context context, AttributeSet attrs) {

super(context, attrs);

init(context);

}

private void init(Context context) {

setCacheColorHint(context.getResources().getColor(R.color.transparent));

inflater = LayoutInflater.from(context);

headView = (LinearLayout) inflater.inflate(R.layout.head, null);

arrowImageView = (ImageView) headView

.findViewById(R.id.head_arrowImageView);

arrowImageView.setMinimumWidth(70);

arrowImageView.setMinimumHeight(50);

progressBar = (ProgressBar) headView

.findViewById(R.id.head_progressBar);

tipsTextview = (TextView) headView.findViewById(R.id.head_tipsTextView);

lastUpdatedTextView = (TextView) headView

.findViewById(R.id.head_lastUpdatedTextView);

measureView(headView);

headContentHeight = headView.getMeasuredHeight();

headContentWidth = headView.getMeasuredWidth();

headView.setPadding(0, -1 * headContentHeight, 0, 0);

headView.invalidate();

Log.v(size, width: + headContentWidth + height:

+ headContentHeight);

addHeaderView(headView, null, false);

setOnScrollListener(this);

animation = new RotateAnimation(0, -180,

RotateAnimation.RELATIVE_TO_SELF, 0.5f,

RotateAnimation.RELATIVE_TO_SELF, 0.5f);

animation.setInterpolator(new LinearInterpolator());

animation.setDuration(250);

animation.setFillAfter(true);

reverseAnimation = new RotateAnimation(-180, 0,

RotateAnimation.RELATIVE_TO_SELF, 0.5f,

RotateAnimation.RELATIVE_TO_SELF, 0.5f);

reverseAnimation.setInterpolator(new LinearInterpolator());

reverseAnimation.setDuration(200);

reverseAnimation.setFillAfter(true);

state = DONE;