Question

我正在尝试在列表视图内的SD卡文件夹中显示图像文件名称。我尝试了很多适配器该适配器使用图像名称的字符串生成器和图像的整数我使用此代码从文件夹中以字符串生成器的形式获取图像 File file = new File（“ sdcard / images”）;

    if (file.isDirectory())
    {
        File[] listFile = file.listFiles();
       mFileStrings = new String[listFile.length];

        for (int i = 0; i < listFile.length; i++)
        {
            mFileStrings[i] = listFile[i].getAbsolutePath();
}

我想将此图像的字符串转换为整数，以便可以在适配器中使用它。因为我遇到以下错误

 Listadapter(String[], integer[]) can not applied to
(String[], String[])

如何以整数形式从文件夹中获取图像？或者我可以编辑我的listadapter以应用String吗？

这是我的列表适配器

公共类ListAdapter扩展了ArrayAdapter {

private final Activity Context;
private final String[] ListItemsName;
private final Integer[] ImageName;

public ListAdapter(Activity context, String[] content,
                   Integer[] ImageName) {

    super(context, R.layout.list_items, content);
    // TODO Auto-generated constructor stub

    this.Context = context;
    this.ListItemsName = content;
    this.ImageName = ImageName;
}
public View getView(int position, View view, ViewGroup parent) {
    LayoutInflater inflater = Context.getLayoutInflater();
    View ListViewSingle = inflater.inflate(R.layout.list_items, null, true);

    TextView ListViewItems = (TextView) ListViewSingle.findViewById(R.id.textView1);
    ImageView ListViewImage = (ImageView) ListViewSingle.findViewById(R.id.imageView1);

    ListViewItems.setText(ListItemsName[position]);
    ListViewImage.setImageResource(ImageName[position]);
    return ListViewSingle;

};

这是我的MainActivity

File dir = new File("sdcard/images");
        File[] filelist = dir.listFiles();
        theNamesOfFiles = new String[filelist.length];
        for (int ii = 0; ii < theNamesOfFiles.length; ii++) {
            theNamesOfFiles[ii] = filelist[ii].getName();
        }
    File file = new File("sdcard/images");
    if (file.isDirectory())
    {
        File[] listFile = file.listFiles();
       mFileStrings = new String[listFile.length];
        for (int i = 0; i < listFile.length; i++)
        {
            mFileStrings[i] = listFile[i].getAbsolutePath();
     result = Integer.parseInt(mFileStrings[i]);        
        }
    }
    list = (ListView) findViewById(R.id.list);   
    ListAdapter la= new ListAdapter(this,theNamesOfFiles,result);
list.setAdapter(la);
    }}

Answer 1

问题是您严重误解了ImageView.setImageResource的工作方式。通过将文件名传递给Integer.parseInt，您不会获得图像资源整数。

mFileStrings[i] = listFile[i].getAbsolutePath();
result = Integer.parseInt(mFileStrings[i]);

我真的不确定您为什么认为这行得通。图片资源整数仅适用于您应用中的资源。对于文件系统中的图像，您可以使用BitmapFactory，但我确实建议您仅使用Glide使其更容易。

将以下内容添加到app/build.gradle依赖项中。

implementation 'com.github.bumptech.glide:glide:4.9.0'

同步您的项目，然后将您的Listadapter更改为此

public class ImagesAdapter extends BaseAdapter {

    private final List<File> imageFiles;

    public ImagesAdapter(List<File> imageFiles) {
        // making a defensive copy of the list
        this.imageFiles = new ArrayList<>(imageFiles);
    }

    public ImagesAdapter(File[] imageFiles) {
        this(Arrays.asList(imageFiles));
    }

    @Override public File getItem(int i) { return imageFiles.get(i); }
    @Override public long getItemId(int position) { return position; }
    @Override public int getCount() { return imageFiles.size(); }

    @Override
    public View getView(int position, View oldView, ViewGroup parent) {
        View view;
        if (oldView == null) {
            LayoutInflater inflater = LayoutInflater.from(parent.getContext());
            view = inflater.inflate(R.layout.list_items, parent, false);
        } else {
            view = oldView;
        }

        TextView nameView = (TextView) view.findViewById(R.id.textView1);
        ImageView imageView = (ImageView) view.findViewById(R.id.imageView1);

        File file = imageFiles.get(position);
        nameView.setText(file.getName());

        Uri uri = Uri.fromFile(file);
        Glide.with(view).load(uri).into(imageView);

        return view;
    }
}

然后将您的MainActivity代码更改为

File imagesDir = new File("sdcard/images");
File[] files = imagesDir.listFiles();

list = (ListView) findViewById(R.id.list); 
list.setAdapter(new ImagesAdapter(files));

将String []转换为integer []

1 个答案: