使用ImageAdapter动态/编程地填充GridView [英] Populating a GridView with ImageViews dynamically/programmatically using a ImageAdapter

问题描述

我尝试开发一个Android应用程序，允许用户从flickr中获取数据，并以 GridView （使用一些不错的3D动画）显示。经过一些冒险，我得到了它几乎运行，但现在我被卡住了。

I try to develop an Android App which allows the user to fetch data from flickr and show it in a GridView (with some nice 3D-Animation). After some adventures i got it almost running, but now I'm stuck.

这是问题：

我有一个UI线程LoadPhotosTask，它从flickr获取图片，就像开源应用程序 photostream 。在该子类的方法 onProgressUpdate（LoadedPhoto ... value）中，我调用 addPhoto（）。直到现在，所有的东西都很好 - 我得到了一些不错的Bitmap和Flickr.photo数据，我需要所有的信息。

I got a UI Thread "LoadPhotosTask" which gets the pictures from flickr, just like the open source application photostream. In the method onProgressUpdate(LoadedPhoto... value) of that subclass I call addPhoto(). Until now everythings fine - I got some nice Bitmap and Flickr.photo data with all the information I need.

        @Override
    public void onProgressUpdate(LoadedPhoto... value) {

        addPhoto(value);
    }

另一方面，我有一个 GridView 。现在我想填写照片。它有一个名为 ImageAdapter （扩展 BaseAdapter 的适配器，请参阅这个教程）。如果我在 ImageAdapter 类中使用数组，我可以使用一些示例图像填充 GridView 。但是如果我想在运行时填充它，我不知道该怎么做。

On the other hand I have got a GridView. Now I want to fill it with the Photos. It has got an adapter called ImageAdapter (which extends BaseAdapter, see this tutorial). If I use an array inside the ImageAdapter class I can populate the GridView with some sample images. But if I want to populate it at runtime, I don't know what to do.

如何在$ $ c $中设置getView方法C> ImageAdapter ？我试图用 addPhoto 中的值填充 ImageAdapter 类中的数组，但不显示任何内容。

How do I have to set up the getView method in the ImageAdapter? I was trying to fill the array inside the ImageAdapter class with my values in addPhoto, but it doesn't display anything.

所以首先我正在设置数组，我想在网格中显示的照片数量（代码位于 ImageAdapter class）：

So first of all I was setting up the array with the amount of Photos i wanted to display in the grid like that (code is inside the ImageAdapter class):

// class variable
private ImageView[] mThumbIds;

    [...] 

    public void setupArray(int count) {
            this.mThumbIds = new ImageView[count];
        }

然后我用我的照片列表的长度调用这个方法：

Then I call this method with the lenght of my photolist:

    final Flickr.PhotoList list = params[0];
        final int count = list.getCount();
        int helper = 0;
    imagead.setupArray(count);

之后我在addPhoto方法中手动调用getView方法：

Afterwards I call the getView method manually inside the addPhoto method:

private void addPhoto(LoadedPhoto... value) {

    ImageView image = (ImageView) mInflater.inflate(
    R.layout.grid_item_photo, null);
    image.setImageBitmap(value[0].mBitmap);
    image.setTag(value[0].mPhoto);

    imagead.setmThumbIds(image, value[0].mPosition);
    imagead.getView(value[0].mPosition, null, mpicturesGrid);

}

这是ImageAdapter中的getView方法：

That is the getView method inside ImageAdapter:

    public View getView(int position, View convertView, ViewGroup parent) {

    if (convertView == null) { // if it's not recycled, initialize some
        // attributes

        imageView = new ImageView(mContext);
        imageView.setLayoutParams(new GridView.LayoutParams(EDGE_LENGTH,
        EDGE_LENGTH));
        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        imageView.setPadding(0, 0, 0, 0);
        imageView.setVisibility(View.VISIBLE);

    } else {

        imageView = (ImageView) convertView;
    }
    imageView.setImageDrawable(mThumbIds[position].getDrawable());
    imageView.setTag(mThumbIds[position].getTag());

    return imageView;

}

推荐答案

缺少关键部分。

当您使用适配器时，您有一种方法称为 notifyDataSetChanged（）。
您缺少的逻辑如下：

When you use an Adapter you have a method called notifyDataSetChanged(). The logic you are missing there is the following:

在适配器中为 GridView 保留适配器将使用的列表的引用。如下所示：

When creating the Adapter for the GridView stay with a reference for the list that the adapter will use. Something like:

private ArrayList<Photo> mPhotos;
private BaseAdapter mAdapter;
private GridView mGridView;

onCreate:

/* other things here */

mAdapter = new MyAdapter(mPhotos);
mGridView.setAdapter(mAdapter);

您添加的照片应该如下：

What you addPhoto should do is the following:

mPhotos.add(photo);
mAdapter.notifyDataSetChanged();

就是这样。

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