你看我有一个 问题: 有没有可能在不完全改变代码的情况下,将该路径改为int?
我使用android studio,目前正在开发应用程序,但我有一件事很困扰。
我有一个图片的字符串路径,需要变成int才能工作。
String path1 = Environment.getDataDirectory().getAbsolutePath() + "/data/sk.lotario.bg/app_imgBuns/0.png";
String path2 = Environment.getDataDirectory().getAbsolutePath() + "/data/sk.lotario.bg/app_imgBuns/1.png";
List<SliderBN> sliderBNS = new ArrayList<>();
for(int i = 0; i < Recipe.bnPos; i++){
sliderBNS.add(new SliderBN(path1));
sliderBNS.add(new SliderBN(path2));
在SliderBN类中,我有这个。
public class SliderBN {
private int image;
SliderBN(int image){
this.image = image;
}
public int getImage() {
return image;
}
问题是我不想在这里把它改成字符串,因为那样我就得改很多代码。
这里是该类的适配器。
private List<SliderBN> sliderBNS;
private ViewPager2 vpBN;
private static final String TAG = "SliderBNAdapter";
public static int vpBNPosition = 0;
public SliderBNAdapter(List<SliderBN> sliderBNS, ViewPager2 vpBN) {
this.sliderBNS = sliderBNS;
this.vpBN = vpBN;
}
public SliderBNAdapter() {
}
@NonNull
@Override
public SliderViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
return new SliderViewHolder(
LayoutInflater.from(parent.getContext()).inflate(
R.layout.slider_item_container,
parent,
false
)
);
}
@Override
public void onBindViewHolder(@NonNull SliderViewHolder holder, int position) {
holder.setImage(sliderBNS.get(position));
if (position == sliderBNS.size()) {
vpBN.post(runnable);
}
}
@Override
public int getItemCount() {
vpBNPosition = vpBN.getCurrentItem();
Log.i(TAG,"position "+vpBNPosition);
return sliderBNS.size();
}
class SliderViewHolder extends RecyclerView.ViewHolder {
private ImageView imageView;
SliderViewHolder(@NonNull View itemView) {
super(itemView);
imageView = itemView.findViewById(R.id.imageSlide);
}
void setImage(SliderBN sliderBN){
imageView.setImageResource(sliderBun.getImage());
}
}
private Runnable runnable = new Runnable() {
@Override
public void run() {
sliderBNS.addAll(sliderBNS);
notifyDataSetChanged();
}
};
你可以在SliderBN中添加两个属性。一个是 String path
另一个是 int index
. 当您创建 SliderBN
你可以直接设置你想要的值。然后在你的代码中你可以使用你需要的属性。
public class SliderBN {
private int index;
private String path;
SliderBN(String path, int index){
this.index = index;
this.path = path;
}
public int getIndex() {
return index;
}
public String getPath() {
return path;
}
}
在一开始创建图片的时候,你可以这样做。
String pathToImages = Environment.getDataDirectory().getAbsolutePath() + "/data/sk.lotario.bg/app_imgBuns/";
List<SliderBN> sliderBNS = new ArrayList<>();
// Here you need to be sure that you always have the images else you will
// receive exceptions! If this images will be dynamically added/removed then
// you need another way for retrieving the names and loading them in the list.
for(int i = 0; i < Recipe.bnPos; i++){
sliderBNS.add(new SliderBN(pathToImages + i + ".png", i));
}
比如你需要设置图片路径的时候,你可以直接调用 getPath
方法。
class SliderViewHolder extends RecyclerView.ViewHolder {
private ImageView imageView;
SliderViewHolder(@NonNull View itemView) {
super(itemView);
imageView = itemView.findViewById(R.id.imageSlide);
}
void setImage(SliderBN sliderBN){
// Here you can set the path to the image
// I saw that you setImageResource(int resId)
// But for this to work you need the Image ids
// In the current case we can use setImageURI(Uri uri)
// With Uri you need to provide the path to the image not the id
File imgFile = new File(sliderBun.getPath());
if(imgFile.exists())
{
Uri uri = Uri.fromFile(imgFile);
imageView.setImageURI(uri);
}
else
{
// Log here message that the file does not exist
// and also log the path so you can see what is going wrong
}
}
}
注意: 由于你的代码是现在这样,你不需要 index (int) in class SliderBN
因为你在一开始添加所有图片的列表中就有这些信息。但我还是不知道你所有的用例,所以我留下了它。请看使用列表的索引来获取该位置的对象的例子。
@Override
public void onBindViewHolder(@NonNull SliderViewHolder holder, int position)
{
// Here we get SliderBN object from the list by list position and not by
// internal properties
holder.setImage(sliderBNS.get(position));
if (position == sliderBNS.size()) {
vpBN.post(runnable);
}
}
有一个地方你会需要索引,那就是如果你有... ... 未排序的列表 SliderBN
对象,并且你需要轻松地对它们进行排序。那么你可以使用这个属性 index
来对该列表中的对象进行排序。但在你的例子中,你是通过增长的索引在 for loop
所以你的名单其实是有排序的。
祝大家好运!