如何在GridView的ImageView中设置不同类型的图像数据

Got it, let's tackle this problem step by step. Here's how you can implement the logic to set the appropriate content for your CircleImageView based on the data types, plus some performance optimizations for your adapter:

Step 1: Add an Image Loading Library #

To handle network image loading efficiently (and avoid writing messy network code yourself), use a library like Glide (or Picasso). For Glide, add this dependency to your module-level build.gradle:

dependencies {
    implementation 'com.github.bumptech.glide:glide:4.16.0'
    annotationProcessor 'com.github.bumptech.glide:compiler:4.16.0'
}

Step 2: Modified Adapter Code #

Here's the updated NameListingAdapter with the required image logic and fixes for view reuse (your original code wasn't reusing convertView, which hurts scrolling performance):

private ArrayList<UserListingModel> dataModel;
Context context;
private static LayoutInflater inflater = null;

public NameListingAdapter(Context context, ArrayList<UserListingModel> models) {
    this.context = context;
    this.dataModel = models;
    inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}

@Override
public int getCount() { 
    return dataModel.size(); 
}

@Override
public UserListingModel getItem(int position) { 
    return dataModel.get(position); 
}

@Override
public long getItemId(int position) { 
    return position; 
}

public class Holder {
    TextView tv;
    CircleImageView img;
}

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    Holder holder;
    View rowView;

    // Reuse existing views to boost performance
    if (convertView == null) {
        rowView = inflater.inflate(R.layout.main_name_list_items, null);
        holder = new Holder();
        holder.tv = rowView.findViewById(R.id.textView1);
        holder.img = rowView.findViewById(R.id.profile_image);
        rowView.setTag(holder);
    } else {
        rowView = convertView;
        holder = (Holder) rowView.getTag();
    }

    UserListingModel currentItem = dataModel.get(position);
    
    // Set TextView content
    holder.tv.setText(currentItem.getName());

    // Handle ImageView content with priority logic
    TextDrawable localDrawable = currentItem.getImg();
    String imageUrl = currentItem.getImageurl();

    if (localDrawable != null) {
        // Priority 1: Use the TextDrawable if it exists
        holder.img.setImageDrawable(localDrawable);
    } else if (imageUrl != null && imageUrl.startsWith("http")) {
        // Priority 2: Load network image if URL is valid
        Glide.with(context)
             .load(imageUrl)
             .placeholder(R.drawable.default_profile_placeholder) // Optional: Add a placeholder
             .error(R.drawable.error_profile_image) // Optional: Add an error fallback
             .into(holder.img);
    } else {
        // Fallback: Set a default image if neither data is available
        holder.img.setImageResource(R.drawable.default_profile);
    }

    rowView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent i = new Intent(context, DashBoardMain.class);
            i.putExtra("Name", currentItem.getName());
            i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            context.startActivity(i);
        }
    });

    return rowView;
}

Key Details Explained: #

• View Reuse: We check if convertView is null before inflating a new view—this cuts down on memory usage and makes scrolling smoother.
• Image Priority Logic:
  1. First, we check if getImg() returns a non-null TextDrawable and use that immediately.
  2. If no local drawable exists, we validate that imageurl is a valid network URL (starts with "http") and use Glide to load it.
  3. A fallback default image is set if neither data type is available—replace the drawable IDs with your own assets.
• Fixed getItem(): Changed it to return the actual UserListingModel instead of the position, which is more standard and useful for future changes.

Alternative: Using Picasso #

If you prefer Picasso over Glide, replace the Glide code block with this:

Picasso.get()
       .load(imageUrl)
       .placeholder(R.drawable.default_profile_placeholder)
       .error(R.drawable.error_profile_image)
       .into(holder.img);

And add Picasso's dependency to your build.gradle:

implementation 'com.squareup.picasso:picasso:2.71828'

内容的提问来源于stack exchange，提问作者NIraj Kumar