自定义控件 CustomListView （下拉刷新）

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自定义的下拉listView 控件

public class CustomListView extends ListView {    int height;    View view;    int downY;    //刷新的四种状态    final static int STATE_DONE = 1; //隐藏时    final static int STATE_PULL = 2;  //下拉时    final static int STATE_RELEASE = 3; //松开时    final static int STATE_REFRESHING = 4; //正在刷新    //当前的状态    int currentState;    TextView tvState;    ImageView ivArrow;    ProgressBar progressBar;    public CustomListView(Context context, AttributeSet attrs) {        super(context, attrs);        currentState = STATE_DONE;        view = View.inflate(getContext(), R.layout.listview_header, null);        this.addHeaderView(view);        // getHeight，控件已经显示出来了        height = view.getHeight();        // Measured测量        // 0是一种测量方式        view.measure(0, 0);        height = view.getMeasuredHeight();        view.setPadding(0, -height, 0, 0);        // this.addFooterView(view);        tvState = (TextView) view.findViewById(R.id.tv_state);        ivArrow = (ImageView) view.findViewById(R.id.iv_arrow);        progressBar = (ProgressBar) view.findViewById(R.id.progressBar);    }    @Override    public boolean onTouchEvent(MotionEvent ev) {        int action = ev.getAction();        switch (action) {        // 按下        case MotionEvent.ACTION_DOWN:            if (currentState == STATE_DONE) {                downY = (int) ev.getY();                // 改变状态                currentState = STATE_PULL;            }            break;        // 移动        case MotionEvent.ACTION_MOVE:            if (currentState == STATE_PULL) {                int currentY = (int) ev.getY();                //控件到顶部的距离                int top = currentY - downY - height;                Log.i("计算top", currentY + ",downY=" + downY + ",height="                        + height + ",top=" + top);                view.setPadding(0, top, 0, 0);                if (currentY - downY > height) {                    this.currentState = STATE_RELEASE;                    tvState.setText("松开刷新");                }            }            break;        // 松开        case MotionEvent.ACTION_UP:            if (currentState == STATE_RELEASE) {                this.currentState = STATE_REFRESHING;                tvState.setText("正在刷新");                // 4,调接口实现类,调用别人代码                if (this.onRefresingListner != null) {                    this.onRefresingListner.onRefresh(this);                }                ivArrow.setVisibility(GONE);                progressBar.setVisibility(VISIBLE);            }            break;        }        return super.onTouchEvent(ev);    }    // 3,接收接口的实现类    public void setOnRefreshingListener(OnRefresingListner onRefresingListner) {        this.onRefresingListner = onRefresingListner;    }    // 2,申明接口对象    OnRefresingListner onRefresingListner;    // 1 写个接中    interface OnRefresingListner {        public void onRefresh(CustomListView customListView);    }//当刷新完成之后     public void refreshComplete() {        this.currentState = STATE_DONE;        view.setPadding(0, -height, 0, 0);        tvState.setText("下拉刷新");        progressBar.setVisibility(GONE);        ivArrow.setVisibility(VISIBLE);    }}

在Activity 中

public class MainActivity extends Activity {    CustomListView customListView;    MyAdatper myAdatper;    ArrayList<String> list = new ArrayList<String>();    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        for (int i = 0; i < 10; i++) {            list.add("data" + i);        }        myAdatper = new MyAdatper(this, list);        customListView = (CustomListView) findViewById(R.id.customListView);        customListView.setAdapter(myAdatper);        customListView.setOnRefreshingListener(new OnRefresingListner() {            @Override            public void onRefresh(final CustomListView customListView) {             //联网  启动工作线程                new Thread(){                    public void run() {                        try {                            //开始连接                            this.sleep(2000);                            String data="联网取到的数据";                            list.add(data);                            //添加完数据 需要更新UI  在主线程中更新                            runOnUiThread(new Runnable() {                                @Override                                public void run() {                                    customListView.refreshComplete();                                    //是1,就是主线程                                    int threadId=(int) Thread.currentThread().getId();                                    myAdatper.notifyDataSetChanged();                                   }                            });                        } catch (Exception e) {                            // TODO: handle exception                        }                    };                }.start();            }        });    }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        // Inflate the menu; this adds items to the action bar if it is present.        getMenuInflater().inflate(R.menu.main, menu);        return true;    }}

layout 布局文件

<?xml version="1.0" encoding="utf-8"?><!-- ListView的头部 --><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:background="#00000000" >    <!-- 内容 -->    <RelativeLayout        android:id="@+id/head_contentLayout"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:paddingLeft="30dp" >        <!-- 箭头图像、进度条 -->        <FrameLayout            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_alignParentLeft="true"            android:layout_centerVertical="true" >            <!-- 箭头 -->            <ImageView                android:id="@+id/iv_arrow"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:layout_gravity="center"                android:src="@drawable/arrow" />            <!-- 进度条 -->            <ProgressBar                android:id="@+id/progressBar"                style="?android:attr/progressBarStyleSmall"                android:layout_width="50dp"                android:layout_height="50dp"                android:layout_gravity="center"                android:visibility="gone" />        </FrameLayout>        <!-- 提示、最近更新 -->        <LinearLayout            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_centerHorizontal="true"            android:gravity="center_horizontal"            android:orientation="vertical" >            <!-- 提示 -->            <TextView                android:id="@+id/tv_state"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:text="下拉刷新"                android:textColor="#FF000000"                android:textSize="20sp" />            <!-- 最近更新 -->            <TextView                android:id="@+id/tv_updateTime"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:text="上次更新"                android:textColor="#FFFF0000"                android:textSize="10sp" />        </LinearLayout>    </RelativeLayout></LinearLayout>

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