Question

我有UICollectionView，其上包含很多自定义单元格。当用户长按时，我有一个长按手势，然后单元格开始摇动＆amp;删除按钮被添加到它们上。当我按下删除按钮时，单元格将从集合视图中删除。

长按代码。

-(void)handleLongPress:(UILongPressGestureRecognizer *)gestureRecognizer
{
    p = [gestureRecognizer locationInView:self.collection_view];
    NSIndexPath *indexPath = [self.collection_view indexPathForItemAtPoint:p];
    if (gestureRecognizer.state != UIGestureRecognizerStateEnded)
    {
        return;
    }

    if (indexPath == nil)
    {
        NSLog(@"couldn't find index path");
    }
    else
    {
        [[NSUserDefaults standardUserDefaults]setValue:@"yes" forKey:@"longPressed"];
        [self.collection_view reloadData];
    }
    if (gestureRecognizer.state == UIGestureRecognizerStateEnded) {
        NSLog(@"UIGestureRecognizerStateEnded");
        //Do Whatever You want on End of Gesture
    }
    else if (gestureRecognizer.state == UIGestureRecognizerStateBegan){
        NSLog(@"UIGestureRecognizerStateBegan.");
        //Do Whatever You want on Began of Gesture
    }

    pgr
    = [[UIPanGestureRecognizer alloc]
       initWithTarget:self action:@selector(handePanPress:)];
    // To detect after how many seconds you want shake the cells
    pgr.delegate = self;
    [self.collection_view addGestureRecognizer:pgr];

    //show the done button here
    navButtonDone = [[UIBarButtonItem alloc] initWithTitle:@"Done" style:UIBarButtonItemStylePlain target:self action:@selector(navBtnDone:)];
    self.navigationItem.rightBarButtonItem = navButtonDone;

}

当长手势开始时，我也会在按下导航栏按钮时在导航栏上添加右键我停止动画＆amp;删除删除按钮。我可以删除iPhone 5s中的删除按钮，但不能删除iPhone 6中的删除按钮。

下面是

的代码

- (IBAction)navBtnDone:(id)sender
{
        if([[[NSUserDefaults standardUserDefaults]valueForKey:@"longPressed"] isEqualToString:@"yes"])
        {
            [[NSUserDefaults standardUserDefaults]setValue:@"no" forKey:@"longPressed"];
            [_deleteButton removeFromSuperview];
            [self.collection_view reloadData];
            [self.collection_view removeGestureRecognizer:pgr];
            self.navigationItem.rightBarButtonItem=nil;
        }
}

这里我刚刚添加了[_deleteButton removeFromSuperview];如何在每个功能中获得单元格＆amp;删除删除按钮。

Answer 1

要根据索引路径检索单元格，可以调用

UICollectionViewCell *someCell = [myCollectionView cellForItemAtIndexPath:indexPath];

然后用

删除删除按钮

if (someCell) {
    // Remove the delete button on the cell.
    [someCell.deleteButton removeFromSuperView];
}

Answer 2

有两种方式。

将IndexPath存储在全局变量中。

在你的.h

public class NotificationServices extends Service
    {
    @Override
    public IBinder onBind(Intent arg0) {return null;}

    @Override
    public void onCreate() {super.onCreate();}

    @SuppressWarnings("static-access")
    @Override
    public int onStartCommand(Intent intent, int flags, int startId)
    {
        JSONObject jsonObject = Utility.jsonObjectFromString(intent.getStringExtra("content"));
        DeadLinesList deadlinesList = new DeadLinesList(jsonObject);
        Date currentdate = Utility.removeTime(new Date());

        String message = "";
        for (DeadLine deadline : deadlineList.getDeadline()){
            if (deadline.getDateDeadline()!= null && Utility.removeTime(deadline.getDateDeadline()).compareTo(currentdate) == 0){
                message += deadline.getDeadlineName()+"\n";
            }

        }
        if (message.length()>0){
            NotificationCompat.Builder b = new NotificationCompat.Builder(Utility.getContext());

                    Intent newIntent = new Intent(Utility.getContext(), MainActivity.class);
                    PendingIntent pIntent = PendingIntent.getActivity(Utility.getContext(),0, newIntent, 0);

                    b.setAutoCancel(true)
                            .setDefaults(Notification.DEFAULT_ALL)
                            .setSmallIcon(R.drawable.icon)
                            .setContentTitle("Message")
                            .setStyle(new NotificationCompat.BigTextStyle()
                                    .bigText(message))
                            .setContentIntent(pIntent)
                            .setDefaults(Notification.DEFAULT_LIGHTS | Notification.DEFAULT_SOUND).build();

                    NotificationManager notificationManager = (NotificationManager) Utility.getContext().getSystemService(Context.NOTIFICATION_SERVICE);
                    notificationManager.notify(1, b.build());
        }
        return START_NOT_STICKY;

    }

    @Override
    public void onDestroy() {super.onDestroy();}

}

在您的手势识别器中

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="com.android.alarm.permission.WAKE_LOCK"/>

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme"
    android:largeHeap="true">

    <receiver android:name=".Notifications.NotificationReceiver">
        <intent-filter>
            <action android:name="ALARM_ACTION"/>
        </intent-filter>
    </receiver>

    <service android:name=".Notifications.NotificationServices"
        android:enabled="true">
    </service>

    <activity
        android:name=".MainActivity"
        android:label="@string/app_name"
        android:theme="@style/AppTheme.NoActionBar"
        android:windowSoftInputMode="adjustPan"
        android:configChanges="keyboardHidden|orientation|screenSize">

        <meta-data
            android:name="android.app.default_searchable"
            android:value=".MainActivity" />

        <meta-data
            android:name="android.app.searchable"
            android:resource="@xml/searchable" />

        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <action android:name="android.intent.action.SEARCH" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

在“删除”按钮操作

 NSIndexPath *globalIndexPath

将Indexpath.row值设置为Barbutton的标记值

-(void)handleLongPress:(UILongPressGestureRecognizer *)gestureRecognizer
{
   p = [gestureRecognizer locationInView:self.collection_view];
   globalIndexPath = [self.collection_view indexPathForItemAtPoint:p];
   //Other Stuff
}

}

在你的按钮操作

- (IBAction)navBtnDone:(id)sender
{
   //Other Stuff
   UICollectionViewCell *cell = [myCollectionView cellForItemAtIndexPath: globalIndexPath];
   if (cell) {
     [cell.deleteButton removeFromSuperView];
   }
}

如何在ios的其他功能中获取集合单元格？

2 个答案: