GridView和使用数组 [英] Gridview and using array

问题描述

首先，我是新来的Andr​​oid和这个论坛发展。我的问题是这样的：我在看世界，你好观点：GridView控件的例子，在想，我怎么动态装载所有我的图片？例如，在 ImageAdapter.java 文件，在年底有：

First, I'm new to developing for Android and this forum. My question is this: I was looking at the "Hello world view: gridview" example and was wondering, how do I load all my images dynamically? For example in the ImageAdapter.java file, at the end there is:

private Integer[] mThumbIds = {
        R.drawable.sample_2, R.drawable.sample_3,
        R.drawable.sample_4, R.drawable.sample_5,
        R.drawable.sample_6, R.drawable.sample_7,
        R.drawable.sample_0, R.drawable.sample_1,
        R.drawable.sample_2, R.drawable.sample_3,
        R.drawable.sample_4, R.drawable.sample_5,
        R.drawable.sample_6, R.drawable.sample_7,
        R.drawable.sample_0, R.drawable.sample_1,
        R.drawable.sample_2, R.drawable.sample_3,
        R.drawable.sample_4, R.drawable.sample_5,
        R.drawable.sample_6, R.drawable.sample_7
};

但是，如果我不知道的图像名称（如用户将添加新的图像）。我想这样做的是从一个XML文件抓取图像名称，然后将其加载到一个数组。我如何做到这一点？

But what if I don't know the images name (as the user will add new images). What I would like to do is grab the image name from an xml file and then load it into an array. How do I accomplish this?

推荐答案

如果要动态显示，是你的设备，你应该光标适配器使用GridView'支持'上的图像（我建议一个SimpleCursorAdapter）。

If you want to dynamically show images that are on your device, you should use a Gridview 'backed' by a cursor adaptor (I would suggest a SimpleCursorAdapter).

相反数组中的硬编码图像的名字，你的适配器将通过创建光标，查询商店获得机器人mediastore数据库中的图像名称。然后你的GridView可以通过执行setAdapter（）调用中使用的适配器。

Instead of hardcoding the image names in an array, your adapter will get the image names from androids mediastore database by creating a 'cursor' that queries the store. Then your gridview can use the adapter by doing a 'setAdapter()' call.

下面是如何使用的CursorAdapter和GridView显示在您的画廊图像的例子：

Here is an example of how to display the images in your gallery using a cursoradapter and gridview:

的http://android-er.blogspot.co.uk/2012/11/list-mediastoreimagesthumbnails-in.html

另外，你将要使用这个计算器的答案@achildress答案提到的示例code：<一href=\"http://stackoverflow.com/questions/5039779/displaying-images-from-a-specific-folder-on-the-sdcard-using-a-gridview\">Displaying使用一个GridView 从SD卡中的特定文件夹的图像

Plus, you will want to use the sample code mentioned in @achildress answer in this stackoverflow answer: Displaying images from a specific folder on the SDCard using a gridview

以下code会给你在特定目录仅适用于图像：

The following code will give you only images in your specific directory:

private Cursor cursor;
private int columnIndex;

首先，获得所在的文件夹中的图像ID的光标：

First, obtain a cursor of image IDs located in the folder:

Gallery g = (Gallery) findViewById(R.id.gallery);
// request only the image ID to be returned
String[] projection = {MediaStore.Images.Media._ID};
// Create the cursor pointing to the SDCard
cursor = managedQuery( MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
        projection, 
        MediaStore.Images.Media.DATA + " like ? ",
        new String[] {"%myimagesfolder%"},  
        null);
// Get the column index of the image ID
columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media._ID);
g.setAdapter(new ImageAdapter(this));

然后，在ImageAdapter的画廊，取得缩略图显示：

Then, in the ImageAdapter for the Gallery, obtain the thumbnail to display:

public View getView(int position, View convertView, ViewGroup parent) {
    ImageView i = new ImageView(context);
    // Move cursor to current position
    cursor.moveToPosition(position);
    // Get the current value for the requested column
    int imageID = cursor.getInt(columnIndex);
    // obtain the image URI
    Uri uri = Uri.withAppendedPath( MediaStore.Images.Media.EXTERNAL_CONTENT_URI, Integer.toString(imageID) );
    String url = uri.toString();
    // Set the content of the image based on the image URI
    int originalImageId = Integer.parseInt(url.substring(url.lastIndexOf("/") + 1, url.length()));
    Bitmap b = MediaStore.Images.Thumbnails.getThumbnail(getContentResolver(),
                    originalImageId, MediaStore.Images.Thumbnails.MINI_KIND, null);
    i.setImageBitmap(b);
    i.setLayoutParams(new Gallery.LayoutParams(150, 100));
    i.setScaleType(ImageView.ScaleType.FIT_XY);
    i.setBackgroundResource(mGalleryItemBackground);
    return i;
}

这篇关于GridView和使用数组的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！