最近看到联想,摩托罗拉等,手机launcher中有个效果,进入mainmenu后,里面的应用程序的图标可以拖来拖去,所以我也参照网上给的代码,写了一个例子。还是很有趣的,实现的流畅度没有人家的那么好,我只是模仿这种效果,我写的这个拖拽是两个图标之间进行交换,所以,当从一行的某个位置,换到下一行的另一列的时候,发现有好几个图标都改变位置了,因为是相邻两个交换位置,所以每经过相邻的图标的时候都改变位置。先弄个雏形,以后再更新优化。
转载请标明出处:http://blog.csdn.net/wdaming1986/article/details/7436881
先看几张效果图,再来研究代码:
横行拖拽:
纵向拖拽的效果图:
下面贴上代码---->在GragGridViewApp-4-7这个工程里面:
1、在包com.cn.daming.adapter中,有三个类----->
1.1、DragAdapter.java这个类中的代码如下:
package com.cn.daming.adapter;
import java.util.ArrayList;
import java.util.Collections;
import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
public abstract class DragAdapter extends BaseAdapter {
protected Context mContext;
protected ArrayList<DragMessage> mlist;
public DragAdapter(Context mContext, ArrayList<DragMessage> mlist) {
this.mContext = mContext;
this.mlist = mlist;
}
public int getCount() {
if (this.mlist != null) {
return this.mlist.size();
}
return 0;
}
public DragMessage getItem(int position) {
return (DragMessage)this.mlist.get(position);
}
public long getItemId(int position) {
return 0;
}
public void addMsg(DragMessage msg){
this.mlist.add(msg);
}
final void reFlag(){
for (DragMessage msg : this.mlist) {
msg.flag = 0;
}
notifyDataSetChanged();
}
final void swap(int srcPosition, int dragPosition){
Collections.swap(this.mlist, srcPosition, dragPosition);
notifyDataSetChanged();
}
final void setFlag(int position, int flag){
getItem(position).flag = flag;
notifyDataSetChanged();
}
public abstract View getView(int position, View convertView, ViewGroup parent);
}
1.2、DragMessage.java这个类中的代码如下:
package com.cn.daming.adapter; public class DragMessage { public static final int MOVE_FLAG = 1; public static final int STATIC_FLAG = 0; public int flag = 0; }
1.3、GragGridView.java核心类中的代码如下:
package com.cn.daming.adapter; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Color; import android.graphics.PixelFormat; import android.graphics.drawable.Drawable; import android.os.Handler; import android.os.Looper; import android.os.Message; import android.util.AttributeSet; import android.util.Log; import android.view.Gravity; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import android.view.WindowManager; import android.widget.AdapterView; import android.widget.GridView; import android.widget.ImageView; public class GragGridView extends GridView{ private ImageView dragImageView;//拖动item的preview private WindowManager windowManager; private WindowManager.LayoutParams windowParams; private int dragSrcPosition; //开始拖拽的位置 private int dragPosition; // 结束拖拽的位置 private int dragPointX;//相对于item的x坐标 private int dragPointY;//相对于item的y坐标 private int dragOffsetX; private int dragOffsetY; private int dragImageId; private int itemHeight; private int itemWidth; private int moveHeight = 0; private int upScrollBounce; private int downScrollBounce; private int dragColor = Color.GRAY; private int changePosition = -1; private long scrollDelayMillis = 10L; private int middleX; private int middleY; private boolean isDrag = false; private RefreshHandler scrollDelayUp = new RefreshHandler(Looper.getMainLooper(), true); private RefreshHandler scrollDelayDown = new RefreshHandler(Looper.getMainLooper(), false); private int scrollHeight = 4; private int maxSH = 20; private int minSH = 4; public void setMoveHeight(int height) { this.moveHeight = height; } public void setDragColor(int color) { this.dragColor = color; } public void setDragImageId(int id) { this.dragImageId = id; } public GragGridView(Context context, AttributeSet attrs) { super(context, attrs); } @Override public boolean onInterceptTouchEvent(MotionEvent ev) { if (ev.getAction() == MotionEvent.ACTION_DOWN) { int x = (int)ev.getX(); int y = (int)ev.getY(); this.dragSrcPosition = this.dragPosition = pointToPosition(x, y); if (this.dragPosition == -1) { return super.onInterceptTouchEvent(ev); } ViewGroup itemView = (ViewGroup)getChildAt(this.dragPosition - getFirstVisiblePosition()); //得到当前点在item内部的偏移量 即相对于item左上角的坐标 this.itemHeight = itemView.getHeight(); this.dragPointX = (x - itemView.getLeft()); this.dragPointY = (y - itemView.getTop()); this.dragOffsetX = (int)(ev.getRawX() - x); this.dragOffsetY = (int)(ev.getRawY() - y); View dragger = itemView.findViewById(this.dragImageId); if ((dragger != null) && (x > dragger.getLeft()&& x < dragger.getRight()) && (y > dragger.getTop() && y < dragger.getBottom())) { if(this.moveHeight <= 0 || (this.moveHeight >= getHeight()/2)) { this.upScrollBounce = (getHeight() / 3); this.downScrollBounce = (getHeight() * 2 / 3); } else { this.upScrollBounce = this.moveHeight; this.downScrollBounce = (getHeight() - this.moveHeight); } //解决问题3 //每次都销毁一次cache,重新生成一个bitmap itemView.destroyDrawingCache(); itemView.setDrawingCacheEnabled(true); Drawable background = itemView.getBackground(); itemView.setBackgroundColor(this.dragColor); Bitmap bitmap = Bitmap.createBitmap(itemView.getDrawingCache()); itemView.setBackgroundDrawable(background); //建立item的缩略图 startDrag(bitmap, x, y); } return false; } return super.onInterceptTouchEvent(ev); } @Override public boolean onTouchEvent(MotionEvent ev) { if ((this.dragImageView != null) && (this.dragPosition != -1)) { int action = ev.getAction(); int moveY = (int)ev.getY(); int moveX = (int)ev.getX(); switch(action) { case MotionEvent.ACTION_UP: int upX = (int)ev.getX(); int upY = (int)ev.getY(); stopDrag(); onDrop(upX, upY); break; case MotionEvent.ACTION_MOVE: if (moveX <= 0) this.middleX = 0; else if (moveX >= getWidth()) this.middleX = getWidth(); else { this.middleX = moveX; } if (moveY <= 0) this.middleY = 0; else if (moveY >= getHeight()) this.middleY = getHeight(); else { this.middleY = moveY; } dragPositionChanged(); onDrag(moveX, moveY); } return true; } return super.onTouchEvent(ev); } private void onDrag(int x, int y) { if (this.dragImageView != null) { this.windowParams.alpha = 0.8F; if (this.middleX - this.dragPointX <= 0) this.windowParams.x = this.dragOffsetX; else if (this.middleX - this.dragPointX >= getWidth() - this.itemWidth) this.windowParams.x = (getWidth() - this.itemWidth + this.dragOffsetX); else { this.windowParams.x = (this.middleX - this.dragPointX + this.dragOffsetX); } if (this.middleY - this.dragPointY <= 0) this.windowParams.y = this.dragOffsetY; else if (this.middleY - this.dragPointY >= getHeight() - this.itemHeight) this.windowParams.y = (getHeight() - this.itemHeight + this.dragOffsetY); else { this.windowParams.y = (this.middleY - this.dragPointY + this.dragOffsetY); } this.windowManager.updateViewLayout(this.dragImageView, this.windowParams); } int tempPosition = pointToPosition(this.middleX, this.middleY); Log.v("daming", "GragGridView ---> 177 tempPosition == "+tempPosition); if (tempPosition != -1) { this.dragPosition = tempPosition; } if ((y >= this.upScrollBounce) && (y <= this.downScrollBounce)) { this.isDrag = false; return; } if (y < this.upScrollBounce) { float a = this.upScrollBounce - this.middleY; float b = this.upScrollBounce; float c = a / b; this.scrollHeight = (int)(c * (this.maxSH - this.minSH) + this.minSH); this.isDrag = true; this.scrollDelayUp.sleep(0L); } else if (y > this.downScrollBounce) { float a = this.middleY - this.downScrollBounce; float b = this.upScrollBounce; float c = a / b; this.scrollHeight = (int)(c * (this.maxSH - this.minSH) + this.minSH); this.isDrag = true; this.scrollDelayDown.sleep(0L); } } private void startDrag(Bitmap bm, int x, int y) { stopDrag(); this.windowParams = new WindowManager.LayoutParams(); //Gravity.TOP|Gravity.LEFT;这个必须加 this.windowParams.gravity = Gravity.TOP|Gravity.LEFT; //得到preview左上角相对于屏幕的坐标 this.windowParams.x = (x - this.dragPointX + this.dragOffsetX); this.windowParams.y = (y - this.dragPointY + this.dragOffsetY); //设置拖拽item的宽和高 this.windowParams.width = WindowManager.LayoutParams.WRAP_CONTENT; this.windowParams.height = WindowManager.LayoutParams.WRAP_CONTENT; this.windowParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE | WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE | WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON | WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN; this.windowParams.format = PixelFormat.TRANSLUCENT; this.windowParams.windowAnimations = 0; ImageView imageView = new ImageView(getContext()); imageView.setImageBitmap(bm); this.windowManager = ((WindowManager)getContext().getSystemService(Context.WINDOW_SERVICE));//“window” this.windowManager.addView(imageView, this.windowParams); this.dragImageView = imageView; } private void stopDrag() { if (this.dragImageView != null) { this.windowManager.removeView(this.dragImageView); this.dragImageView = null; } this.changePosition = -1; this.isDrag = false; } private void dragPositionChanged(){ DragAdapter adapter = (DragAdapter)getAdapter(); if (this.changePosition != this.dragPosition) { if (this.changePosition == -1) { this.changePosition = this.dragPosition; adapter.setFlag(this.changePosition, 1); return; } adapter.swap(this.changePosition, this.dragPosition); this.changePosition = this.dragPosition; } } public void setMaxSH(int sh){ this.maxSH = sh; } public void setMinSH(int sh){ this.minSH = sh; } private void onDrop(int x, int y){ //为了避免滑动到分割线的时候,返回-1的问题 int tempPosition = pointToPosition(x, y); if(tempPosition!=INVALID_POSITION){ dragPosition = tempPosition; } //超出边界处理 if(y<getChildAt(0).getTop()){ //超出上边界 dragPosition = 0; }else if(y>getChildAt(getChildCount()-1).getBottom()|| (y>getChildAt(getChildCount()-1).getTop()&&x>getChildAt(getChildCount()-1).getRight())){ //超出下边界 dragPosition = getAdapter().getCount()-1; } //数据交换 if(dragPosition!=dragSrcPosition&&dragPosition>-1&&dragPosition<getAdapter().getCount()){ DragAdapter adapter = (DragAdapter)getAdapter(); adapter.reFlag(); } // DragAdapter adapter = (DragAdapter)getAdapter(); // adapter.reFlag(); } private void actDown(){ int tempPosition = pointToPosition(this.middleX, this.middleY); if (tempPosition != AdapterView.INVALID_POSITION) { this.dragPosition = tempPosition; } dragPositionChanged(); } private void actUp(){ int tempPosition = pointToPosition(this.middleX, this.middleY); if (tempPosition != AdapterView.INVALID_POSITION) { this.dragPosition = tempPosition; } dragPositionChanged(); } class RefreshHandler extends Handler { boolean isUp; public RefreshHandler(Looper looper, boolean isUp){ super(looper); this.isUp = isUp; } public RefreshHandler(Looper l) { super(l); } public void handleMessage(Message msg){ if (GragGridView.this.isDrag) { if (this.isUp) GragGridView.this.actUp(); else { GragGridView.this.actDown(); } sleep(GragGridView.this.scrollDelayMillis); } } public void sleep(long delayMillis) { sendMessageDelayed(obtainMessage(0), delayMillis); } } }
2、在包com.cn.daming.draggridview中,有两个类---->
2.1、GragGridViewAppActivity.java入口类中的代码:
package com.cn.daming.draggridview;
import java.util.ArrayList;
import android.app.Activity;
import android.content.Context;
import android.graphics.Color;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import com.cn.daming.adapter.DragAdapter;
import com.cn.daming.adapter.DragMessage;
import com.cn.daming.adapter.GragGridView;
public class GragGridViewAppActivity extends Activity {
private MyAdapter myAdapter;
private ArrayList<DragMessage> mlist = new ArrayList<DragMessage>();
private GragGridView mGridView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.drag_grid_activity);
initDate();
mGridView = (GragGridView)findViewById(R.id.drag_grid);
myAdapter = new MyAdapter(this, mlist);
mGridView.setAdapter(myAdapter);
//设置触发拖动的区域,用一个ImageView来设置,这个必须设置
mGridView.setDragImageId(R.id.grag_grid_item_view);
//以下这些都做了相应的处理,不设置没关系,而且效果也不错
//设置拖动浮项的背景色
// mListView.setDragColor(Color.RED);
//设置滚动的最大像素
// mListView.setMaxSH(sh);
//设置滚动的最小像素
// mListView.setMinSH(sh);
//设置滚动区的高度(2*height应该小于ListView自己的高度)
// mListView.setMoveHeight(height);
}
private void initDate(){
for (int i = 1; i <= 100; i++) {
MyMessage msg = new MyMessage();
String str = "DM_" + i;
msg.msg = str;
mlist.add(msg);
}
}
class MyAdapter extends DragAdapter{
Drawable background;
public MyAdapter(Context mContext, ArrayList<DragMessage> mlist) {
super(mContext, mlist);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View view = convertView;
ViewHolder holder = null;
if (view == null) {
view = LayoutInflater.from(mContext).inflate(
R.layout.drag_grid_item, null);
holder = new ViewHolder();
holder.tv = (TextView) view
.findViewById(R.id.drag_grid_item_text);
holder.iv = (ImageView) view
.findViewById(R.id.drag_grid_item_image);
view.setTag(holder);
} else {
holder = (ViewHolder) view.getTag();
}
holder.tv.setText(((MyMessage)getItem(position)).msg);
holder.iv.setBackgroundResource(R.drawable.title2);
if(background == null){
background = view.getBackground();}
if(getItem(position).flag == DragMessage.MOVE_FLAG){
view.setBackgroundColor(Color.GRAY);
}
else{
view.setBackgroundDrawable(background);
}
return view;
}
}
private class ViewHolder {
TextView tv;
ImageView iv;
}
}
2.2、MyMessage.java中的代码:
package com.cn.daming.draggridview;
import com.cn.daming.adapter.DragMessage;
public class MyMessage extends DragMessage{
public String msg;
}
3、布局文件layout有两个----->
3.1、drag_grid_activity.xml中的代码如下:
<?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="fill_parent"
android:orientation="vertical" >
<com.cn.daming.adapter.GragGridView
android:id="@+id/drag_grid"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:numColumns="auto_fit"
android:columnWidth="70dp"
android:stretchMode="columnWidth"
android:gravity="center"
android:layout_gravity="center"
android:cacheColorHint="#00000000"/>
</LinearLayout>
3.2、drag_grid_item.xml中的代码如下:
<?xml version="1.0" encoding="utf-8"?>
<!-- 一定要使用相对布局 -->
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:background="#FFFFFF"
android:id="@+id/grag_grid_item_view"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView
android:id="@+id/drag_grid_item_text"
android:layout_width="wrap_content"
android:layout_height="50dp"
android:paddingLeft="5dip"
android:gravity="center"
android:textColor="#ffff00ff"
android:layout_below="@+id/drag_grid_item_image"
android:capitalize="none"
/>
<ImageView
android:id="@+id/drag_grid_item_image"
android:layout_width="50dp"
android:layout_height="50dp"
android:scaleType="center"
/>
</RelativeLayout>
有问题的可以留言,欢迎大家来讨论研究,分享知识,共同进步!
以下是我在开发中遇到问题的参考资料:
http://www.cnblogs.com/qianxudetianxia/archive/2011/06/19/2084886.html
http://lipeng88213.iteye.com/blog/1099621
http://hi.baidu.com/jwq359699768/blog/item/f2caee8741e71131c75cc369.html