ArrayAdapter:按索引删除 [英] ArrayAdapter : Remove by Index

问题描述

我有一个由新闻服务器摘要填充的ListView(只是一个故事素材列表)和一个arrayAdapter来修改该ListView.

I have a ListView that is populated by a news server rundown (just a list of story slugs) and an arrayAdapter to modify that ListView.

我可以通过'remove(Object)'函数删除项目，但是如果有多个'Object'实例怎么办? remove()仅删除对象"的第一个实例.例如，如果不删除第一个对象，则无法删除阵列适配器中的第二个对象".所以我的问题是我该如何解决?

I can remove items by the 'remove(Object)' function but what if there are multiple instances of 'Object'? remove() only removed the first instance of 'Object'. I cannot remove, for example, the second 'Object' in my array adapter without removing the first one. So my question is how can i work around this?

ex:摘要A

story 1 
story 2
Break
story 3
story 4
Break
story 5
etc...

因此在此示例中，我无法删除第二个"Break"，因为remove('Break')会删除第一个"Break".如果我可以removeByIndex(5)，那将是完美的，但是....

so in this example i cannot delete the Second 'Break' because remove('Break') will remove the first one. if i could removeByIndex(5), that would be perfect but....

我曾尝试编写自己的remove函数，该函数将使用除指定索引之外的所有成员创建一个全新的适配器.这就是我在玩弄的东西.

Ive tried writing my own remove function that creates a whole new adapter with all members but the specified index. here is what i was messing around with.

public ArrayAdapter<String> removeIndex(ArrayAdapter<String> arr, int index) {
    ArrayAdapter<String> temp = new ArrayAdapter<String>(arr.getContext(),R.layout.list_item);
    for(int i =0 ; i<arr.getCount();i++){
        if(i != index) temp.add(arr.getItem(i));
    }
    return temp;
}

寻求帮助或建议.

推荐答案

使用List自己处理字符串集合，然后将该对象传递给ArrayAdapter的构造函数.这为您提供了对列表的引用，因此您可以更改数据，同时允许适配器根据需要进行管理和显示.

Handle the collection of strings yourself with a List and pass the object into the constructor of the ArrayAdapter. This leaves you with a reference to the List so you can alter the data while allowing the adapter to manage and display as needed.

注意:修改数据对象时，您必须调用

Note: When modifying the data object you must call

myAdapter.notifyDataSetChanged()

之后

-必须也位于UI线程上.显然，列表的更改不必在UI线程上进行，并且很可能在UI线程上不发生.

private ArrayList<String> mData = new ArrayList<String>();
private ArrayAdapter<String> mAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    // ...
    // Code that adds the strings
    // Create the list adapter
    mAdapter = new ArrayAdapter<String>(myActivity.this, android.R.layout.simple_list_item_1, mData);
}

private void removeItem(int index) {
    mData.removeAt(index);
    myActivity.this.runOnUiThread(new Runnable() {
        public void run() {
            mAdapter.notifyDataSetChanged();
        }
    }
}

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