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本篇内容主要讲解“Android 的 ListView 怎么使用”，感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷，实用性强。下面就让丸趣 TV 小编来带大家学习“Android 的 ListView 怎么使用”吧!
在 Android 开发 中, 经常会要用到水平水平 ListView(HorizontalListView), 但是,Android 官方并没有提供这样一个控件, 所以在这里我给大家分享一下我在项目中用到的一个水平水平 ListView, 非常好用, 使用过程 中与 ListView 是一样的, 实例化组件, 设置数据, 设置 Adaper.
package com.example.horizontallistview.hl.widget;
import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListAdapter;
public abstract class HorizontalListView extends AdapterView ListAdapter { public HorizontalListView(Context context) { super(context);
}
public HorizontalListView(Context context, AttributeSet attrs) { super(context, attrs);
}
public HorizontalListView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle);
}
public abstract int getScreenPositionForView(View view);
/**
* Interface definition for a callback to be invoked when an item in this
* view has been clicked and held.
*/
public interface OnItemDragListener {
/**
* Callback method to be invoked when an item in this view has been
* dragged outside the vertical tolerance area.
*
* Implementers can call getItemAtPosition(position) if they need to
* access the data associated with the selected item.
*
* @param parent
* The AbsListView where the click happened
* @param view
* The view within the AbsListView that was clicked
* @param position
* The position of the view in the list
* @param id
* The row id of the item that was clicked
*
* @return true if the callback consumed the long click, false otherwise
*/
boolean onItemStartDrag(AdapterView ? parent, View view, int position,
long id);
}
public interface OnLayoutChangeListener {
void onLayoutChange(boolean changed, int left, int top, int right,
int bottom);
}
public interface OnScrollFinishedListener {
/**
* Callback method to be invoked when the scroll has completed.
*
* @param currentX
* The current scroll position of the view
*/
void onScrollFinished(int currentX);
}
}为什么要继承 AdapterView, 大家可以去看看 Android 提供的 ListView 是怎么实现的,
public class ListView extends AbsListViewpublic abstract class AbsListView extends AdapterView ListAdapter implements TextWatcher,
ViewTreeObserver.OnGlobalLayoutListener, Filter.FilterListener,
ViewTreeObserver.OnTouchModeChangeListener,
RemoteViewsAdapter.RemoteAdapterConnectionCallback {大家 对比去看看官方文档实现 ListView 的类就知道了. 这里我就不再多说了
大家 注意 HorizontalListView 只是 一个抽象类, 所以我们不能直接用它, 需要用一个类来实现里面的方法
public class HorizontalVariableListView extends HorizontalListView implements
OnGestureListener, FlingRunnableView {
public enum SelectionMode {
Single, Multiple
};
public interface OnItemClickedListener {
/**
* Callback method to be invoked when an item in this AdapterView has
* been clicked.
* p
* Implementers can call getItemAtPosition(position) if they need to
* access the data associated with the selected item.
*
* @param parent
* The AdapterView where the click happened.
* @param view
* The view within the AdapterView that was clicked (this
* will be a view provided by the adapter)
* @param position
* The position of the view in the adapter.
* @param id
* The row id of the item that was clicked.
* @return if the implementation return false, then the selection will
* not be updated
*/
boolean onItemClick(AdapterView ? parent, View view, int position,
long id);
}
public static final int OVER_SCROLL_ALWAYS = 0;
public static final int OVER_SCROLL_IF_CONTENT_SCROLLS = 1;
public static final int OVER_SCROLL_NEVER = 2;
protected static final String LOG_TAG = horizontal-variable-list
private static final float WIDTH_THRESHOLD = 1.1f;
protected int mAlignMode = Gravity.CENTER;
protected SparseBooleanArray mSelectedPositions = new SparseBooleanArray();
protected int mHeight = 0;
protected int mPaddingTop = 0;
protected int mPaddingBottom = 0;
protected ListAdapter mAdapter;
private int mAdapterItemCount;
private int mLeftViewIndex = -1;
private int mRightViewIndex = 0;
private GestureDetector mGesture;
private List Queue View mRecycleBin;
private List Integer mChildWidths = new ArrayList Integer
private List Integer mChildHeights = new ArrayList Integer
private boolean mDataChanged = false;
private IFlingRunnable mFlingRunnable;
private boolean mForceLayout;
private int mDragTolerance = 0;
private boolean mDragScrollEnabled;
protected EdgeGlow mEdgeGlowLeft, mEdgeGlowRight;
private int mOverScrollMode = OVER_SCROLL_NEVER;
private Matrix mEdgeMatrix = new Matrix();
private ScrollNotifier mScrollNotifier;
private SelectionMode mChoiceMode = SelectionMode.Single;
private OnItemSelectedListener mOnItemSelected;
private OnItemClickedListener mOnItemClicked;
private OnItemDragListener mItemDragListener;
private OnScrollChangedListener mScrollListener;
private OnScrollFinishedListener mScrollFinishedListener;
private OnLayoutChangeListener mLayoutChangeListener;
public void setOnItemDragListener(OnItemDragListener listener) {
mItemDragListener = listener;
}
public void setOnScrollListener(OnScrollChangedListener listener) {
mScrollListener = listener;
}
public void setOnLayoutChangeListener(OnLayoutChangeListener listener) {
mLayoutChangeListener = listener;
}
public void setOnScrollFinishedListener(OnScrollFinishedListener listener) {
mScrollFinishedListener = listener;
}
public OnItemDragListener getOnItemDragListener() {
return mItemDragListener;
}
/**
* Controls how selection is managed within the list. br /
* Single or multiple selections are supported
*
* @see SelectionMode
* @param mode
* the selection mode
*/
public void setSelectionMode(SelectionMode mode) {
mChoiceMode = mode;
}
/**
* Returns the current selection mode
*
* @see SelectionMode
* @return
*/
public SelectionMode getChoiceMode() {
return mChoiceMode;
}
/**
* Instantiates a new horizontial fixed list view.
*
* @param context
* the context
* @param attrs
* the attrs
*/
public HorizontalVariableListView(Context context, AttributeSet attrs) { super(context, attrs);
initView();
}
public HorizontalVariableListView(Context context, AttributeSet attrs,
int defStyle) { super(context, attrs, defStyle);
initView();
}
private synchronized void initView() { if (Build.VERSION.SDK_INT 8) {
try { mFlingRunnable = (IFlingRunnable) ReflectionUtils
.newInstance(
com.iotdc.android.app.shopping.HorizontalVariableListView.widget.Fling9Runnable ,
new Class ? [] { FlingRunnableView.class,
int.class }, this, mAnimationDuration);
} catch (ReflectionException e) { mFlingRunnable = new Fling8Runnable(this, mAnimationDuration);
}
} else { mFlingRunnable = new Fling8Runnable(this, mAnimationDuration);
}
mLeftViewIndex = -1;
mRightViewIndex = 0;
mMaxX = Integer.MAX_VALUE;
mMinX = 0;
mRightEdge = 0;
mLeftEdge = 0;
mGesture = new GestureDetector(getContext(), mGestureListener);
mGesture.setIsLongpressEnabled(false);
setFocusable(true);
setFocusableInTouchMode(true);
ViewConfiguration configuration = ViewConfiguration.get(getContext());
mTouchSlop = configuration.getScaledTouchSlop();
mDragTolerance = mTouchSlop;
mOverscrollDistance = 10;
mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();
mMinimumVelocity = configuration.getScaledMinimumFlingVelocity();
}
public void setOverScrollMode(int mode) {
mOverScrollMode = mode;
if (mode != OVER_SCROLL_NEVER) { if (mEdgeGlowLeft == null) { Drawable glow = getContext().getResources().getDrawable( R.drawable.overscroll_glow);
Drawable edge = getContext().getResources().getDrawable( R.drawable.overscroll_edge);
mEdgeGlowLeft = new EdgeGlow(edge, glow);
mEdgeGlowRight = new EdgeGlow(edge, glow);
mEdgeGlowLeft.setColorFilter(0xFF33b5e5, Mode.MULTIPLY);
}
} else {
mEdgeGlowLeft = mEdgeGlowRight = null;
}
}
public void setEdgeHeight(int value) {
mEdgesHeight = value;
}
public void setEdgeGravityY(int value) {
mEdgesGravityY = value;
}
@Override
public void trackMotionScroll(int newX) { scrollTo(newX, 0);
mCurrentX = getScrollX();
removeNonVisibleItems(mCurrentX);
fillList(mCurrentX);
invalidate();
}
@Override
protected void dispatchDraw(Canvas canvas) { super.dispatchDraw(canvas);
if (getChildCount() 0) { drawEdges(canvas);
}
}
.....
....
....当然了 , 这个类很复杂, 就不把代码贴出来了, 在下面我们把这个 demo 代码上传的, 希望大家可以去下载, 研究, 然后把代码整合到自己的项目中使用.
package com.example.horizontallistview;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Toast;
import com.example.horizontallistview.hl.widget.HorizontalVariableListView;
import com.example.horizontallistview.hl.widget.HorizontalVariableListView.OnItemClickedListener;
public class MainActivity extends Activity {
private HorizontalVariableListView lv;
private MyAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lv = (HorizontalVariableListView) findViewById(R.id.lv_horizontal);
String[] items = new String[20];
adapter = new MyAdapter(this, items);
lv.setAdapter(adapter);
lv.setSelectionMode(HorizontalVariableListView.SelectionMode.Single);
lv.setOnItemClickedListener(new OnItemClickedListener() {
@Override
public boolean onItemClick(AdapterView ? parent, View view, int position,
long id) {
// 水平 ListView 的点击 item 事件
Toast.makeText(MainActivity.this, position + , 1).show();
return false;
}
});
}
@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;
}
}在 Activity 中就是这么使用这个控件就行了, 是不是很简单, 与 Listview 是一样的用法
我再把 activity_main.xml 文件代码贴出来
LinearLayout 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:orientation= vertical
com.example.horizontallistview.hl.widget.HorizontalVariableListView
android:id= @+id/lv_horizontal
android:layout_width= match_parent
android:layout_height= 120dp
android:layout_marginLeft= 5dp
android:layout_marginRight= 5dp
android:gravity= bottom|center_vertical
android:paddingBottom= 0dp
android:paddingTop= 0dp /
/LinearLayout到此，相信大家对“Android 的 ListView 怎么使用”有了更深的了解，不妨来实际操作一番吧！这里是丸趣 TV 网站，更多相关内容可以进入相关频道进行查询，关注我们，继续学习！
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