小編給大家分享一下Android如何實現可拖拽的GridView效果長按可拖拽刪除數據源，相信大部分人都還不怎么了解，因此分享這篇文章給大家參考一下，希望大家閱讀完這篇文章后大有收獲，下面讓我們一起去了解一下吧！
Android 可拖拽的GridView效果實現, 長按可拖拽和item實時交換
簡單修改，完成自己想要的功能：長按，移到垃圾桶，刪除數據。
主要思路是：
1.獲取到用戶長按的操作
2.獲取按下的圖片的bitmap以及移動的時候動態刷新鏡像
3 action_up的時候判斷鏡像的位置，進入是否刪除邏輯
自定義控件
package com.leafact.GridView;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.os.Handler;
import android.os.Vibrator;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.View;
import android.view.WindowManager;
import android.widget.AdapterView;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.Toast;
/**
* 長按能選中item的，丟入垃圾箱的gridView
*
* @author leafact
*
*/
public class MoveGridView extends GridView {
private WindowManager mWindowManager;
/**
* item鏡像的布局參數
*/
private WindowManager.LayoutParams mWindowLayoutParams;
/**
* 震動器
*/
private Vibrator mVibrator;
// 震動的時間，默認為100ms
private long vibratorMs = 100;
// 設置長按時間為1秒
private long responseMS = 1000;
private static boolean isMove = false;
// 按下去的x,y
private int mDownX = 0;
private int mDownY = 0;
// 移動的時候的x,y
private int mMoveX = 0;
private int mMoveY = 0;
// 抬起的x,y
private int mUpX = 0;
private int mUpY = 0;
private int mPoint2ItemTop;
private int mPoint2ItemLeft;
private int mOffset2Top;
private int mOffset2Left;
/**
* 狀態欄的高度
*/
private int mStatusHeight;
public MoveGridView(Context context, AttributeSet attrs) {
super(context, attrs);
mVibrator = (Vibrator) context
.getSystemService(Context.VIBRATOR_SERVICE);
mWindowManager = (WindowManager) context
.getSystemService(Context.WINDOW_SERVICE);
mStatusHeight = getStatusHeight(context); // 獲取狀態欄的高度
}
// 要移動的item的位置,默認為INVALID_POSITION=-1
private int mMovePosition = INVALID_POSITION;
/**
* 剛開始拖拽的item對應的View
*/
private View mStartMoveItemView = null;
private ImageView mMoveImageView = null;
private Bitmap mMoveBitmap;
private Handler mHandler = new Handler();
// 判斷是否能開始移動元素
private Runnable mLongClickRunnable = new Runnable() {
@Override
public void run() {
isMove = true;
mVibrator.vibrate(vibratorMs);
// 根據我們按下的點顯示item鏡像
createDragImage(mMoveBitmap, mDownX, mDownY);
}
};
@Override
public boolean onTouchEvent(MotionEvent ev) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
mDownX = (int) ev.getX();
mDownY = (int) ev.getY();
System.out.println("ACTION_DOWN");
// 根據按下的X,Y坐標獲取所點擊item的position
mMovePosition = pointToPosition(mDownX, mDownY);
// 如果選中的為非法的位置。則不處理消息
if (mMovePosition == AdapterView.INVALID_POSITION) {
break;
}
mHandler.postDelayed(mLongClickRunnable, responseMS);
mStartMoveItemView = getChildAt(mMovePosition
- getFirstVisiblePosition());
mPoint2ItemTop = mDownY - mStartMoveItemView.getTop();
mPoint2ItemLeft = mDownX - mStartMoveItemView.getLeft();
mOffset2Top = (int) (ev.getRawY() - mDownY);
mOffset2Left = (int) (ev.getRawX() - mDownX);
// 開啟mMoveItemView繪圖緩存
mStartMoveItemView.setDrawingCacheEnabled(true);
// 獲取mMoveItemView在緩存中的Bitmap對象
mMoveBitmap = Bitmap.createBitmap(mStartMoveItemView
.getDrawingCache());
// 這一步很關鍵，釋放繪圖緩存，避免出現重復的鏡像
mStartMoveItemView.destroyDrawingCache();
break;
case MotionEvent.ACTION_MOVE:
mMoveX = (int) ev.getX();
mMoveY = (int) ev.getY();
// 如果我們在按下的item上面移動，只要不超過item的邊界我們就不移除mRunnable
// 依然能監聽到longClick
if (!isTouchInItem(mStartMoveItemView, mMoveX, mMoveY)) {
mHandler.removeCallbacks(mLongClickRunnable);
}
// //禁止Gridview側邊進行滑動,移動的時候不許發生側滑事件
if (isMove) {
onDragItem(mMoveX, mMoveY);
return true;
}
break;
case MotionEvent.ACTION_UP:
mUpX = (int) ev.getX();
mUpY = (int) ev.getY();
mHandler.removeCallbacks(mLongClickRunnable);
if(isMove){
deleteIfNeed();
}
removeDragImage();
isMove = false;
break;
default:
break;
}
return super.onTouchEvent(ev);
}
/**
* 判斷是否要刪除，滿足條件刪除
*/
private void deleteIfNeed() {
int y = mUpY - mPoint2ItemTop + mOffset2Top
- mStatusHeight;
if(y<50){
if(mUninstallListener!=null)
mUninstallListener.onUninstallListener(mMovePosition);
}
}
/**
* 是否點擊在GridView的item上面
*
* @param itemView
* @param x
* @param y
* @return
*/
private boolean isTouchInItem(View dragView, int x, int y) {
if (dragView == null) {
return false;
}
int leftOffset = dragView.getLeft();
int topOffset = dragView.getTop();
if (x < leftOffset || x > leftOffset + dragView.getWidth()) {
return false;
}
if (y < topOffset || y > topOffset + dragView.getHeight()) {
return false;
}
return true;
}
/**
* 創建拖動的鏡像
*
* @param bitmap
* @param downX
* 按下的點相對父控件的X坐標
* @param downY
* 按下的點相對父控件的X坐標
*/
private void createDragImage(Bitmap bitmap, int downX, int downY) {
mWindowLayoutParams = new WindowManager.LayoutParams();
mWindowLayoutParams.format = PixelFormat.TRANSLUCENT; // 圖片之外的其他地方透明
mWindowLayoutParams.gravity = Gravity.TOP | Gravity.LEFT;
mWindowLayoutParams.x = downX - mPoint2ItemLeft + mOffset2Left;
mWindowLayoutParams.y = downY - mPoint2ItemTop + mOffset2Top
- mStatusHeight;
mWindowLayoutParams.alpha = 0.55f; // 透明度
mWindowLayoutParams.width = WindowManager.LayoutParams.WRAP_CONTENT;
mWindowLayoutParams.height = WindowManager.LayoutParams.WRAP_CONTENT;
mWindowLayoutParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
| WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE;
mMoveImageView = new ImageView(getContext());
mMoveImageView.setImageBitmap(bitmap);
mWindowManager.addView(mMoveImageView, mWindowLayoutParams);
}
/**
* 從界面上面移動拖動鏡像
*/
private void removeDragImage() {
if (mMoveImageView != null) {
mWindowManager.removeView(mMoveImageView);
mMoveImageView = null;
}
}
/**
* 拖動item，在里面實現了item鏡像的位置更新，item的相互交換以及GridView的自行滾動
*
* @param x
* @param y
*/
private void onDragItem(int moveX, int moveY) {
mWindowLayoutParams.x = moveX - mPoint2ItemLeft + mOffset2Left;
mWindowLayoutParams.y = moveY - mPoint2ItemTop + mOffset2Top
- mStatusHeight;
mWindowManager.updateViewLayout(mMoveImageView, mWindowLayoutParams); // 更新鏡像的位置
}
/**
* 獲取狀態欄的高度
*
* @param context
* @return
*/
private static int getStatusHeight(Context context) {
int statusHeight = 0;
Rect localRect = new Rect();
((Activity) context).getWindow().getDecorView()
.getWindowVisibleDisplayFrame(localRect);
statusHeight = localRect.top;
if (0 == statusHeight) {
Class<?> localClass;
try {
localClass = Class.forName("com.android.internal.R$dimen");
Object localObject = localClass.newInstance();
int i5 = Integer.parseInt(localClass
.getField("status_bar_height").get(localObject)
.toString());
statusHeight = context.getResources().getDimensionPixelSize(i5);
} catch (Exception e) {
e.printStackTrace();
}
}
return statusHeight;
}
/**
* 設置響應拖拽的毫秒數，默認是1000毫秒
*
* @param responseMS
*/
public void setResponseMS(long responseMS) {
this.responseMS = responseMS;
}
/**
* 設置震動時間的毫秒數，默認是1000毫秒
*
* @param responseMS
*/
public void setVibrator(long vibratorMs) {
this.vibratorMs = vibratorMs;
}
public void setOnUninstallListener(UninstallListener l){
mUninstallListener=l;
};
private UninstallListener mUninstallListener;
}MainActivity.java
package com.example.gridviewmovedemo;
import java.util.ArrayList;
import java.util.HashMap;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemLongClickListener;
import android.widget.SimpleAdapter;
import com.leafact.GridView.MoveGridView;
import com.leafact.GridView.UninstallListener;
public class MainActivity extends Activity {
private MoveGridView mMoveGridView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mMoveGridView = (MoveGridView) findViewById(R.id.gridview);
final ArrayList<HashMap<String, Object>> lstImageItem = new ArrayList<HashMap<String, Object>>();
for (int i = 0; i < 10; i++) {
HashMap<String, Object> map = new HashMap<String, Object>();
map.put("ItemText", "NO." + String.valueOf(i));// 按序號做ItemText
lstImageItem.add(map);
}
final SimpleAdapter saImageItems = new SimpleAdapter(this,
lstImageItem,// 數據來源
R.layout.gridview_item,
// 動態數組與ImageItem對應的子項
new String[] { "ItemText" },
// ImageItem的XML文件里面的一個ImageView,兩個TextView ID
new int[] { R.id.ItemText });
// 添加并且顯示
mMoveGridView.setAdapter(saImageItems);
//監聽到卸載刪除數據
mMoveGridView.setOnUninstallListener(new UninstallListener() {
@Override
public void onUninstallListener(int position) {
lstImageItem.remove(position);
saImageItems.notifyDataSetChanged();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}UninstallListener.java
package com.leafact.GridView;
public interface UninstallListener {
void onUninstallListener(int position);
}activity_main.xml
<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:background="#fff" android:orientation="vertical" tools:context=".MainActivity" > <RelativeLayout android:layout_width="fill_parent" android:layout_height="100dip" android:background="#ccc" > <TextView android:layout_width="wrap_content" android:layout_height="fill_parent" android:layout_centerHorizontal="true" android:gravity="center" android:text="卸載" android:textColor="#fff" android:textSize="28sp" /> </RelativeLayout> <com.leafact.GridView.MoveGridView android:id="@+id/gridview" android:layout_width="fill_parent" android:layout_height="fill_parent" android:horizontalSpacing="5dip" android:numColumns="3" android:verticalSpacing="5dip" /> </LinearLayout>
gridview_item.xml
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content" android:background="#2248DD" > <TextView android:id="@+id/ItemText" android:layout_width="wrap_content" android:layout_height="100dip" android:layout_centerHorizontal="true" android:gravity="center" > </TextView> </RelativeLayout>
以上是“Android如何實現可拖拽的GridView效果長按可拖拽刪除數據源”這篇文章的所有內容，感謝各位的閱讀！相信大家都有了一定的了解，希望分享的內容對大家有所幫助，如果還想學習更多知識，歡迎關注億速云行業資訊頻道！
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