问题描述
这是我的 BaseAdapter 类,我想在这里实现视图绑定。我是怎么做到的。从而我可以减少没有。我的应用程序中的行数。
public class MyAdapter extends BaseAdapter {
Context c;
int items[];
MyAdapter(Context c,int arr[]) {
this.c = c;
items = arr;
}
@Override
public int getCount() {
return items.length;
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(int position,View convertView,ViewGroup parent) {
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) c.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.grid_layout,null);
}
ImageView imageView = convertView.findViewById(R.id.imageView);
imageView.setimageResource(items[position]);
return convertView;
}
}
这是 MainActivity.java 文件,对基适配器的调用来自这个类文件
public class MainActivity extends AppCompatActivity {
ActivityMainBinding binding;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
binding = ActivityMainBinding.inflate(getLayoutInflater());
setContentView(binding.getRoot());
int[] itemsarray = new int[] {
R.drawable.ic_launcher_background,R.drawable.ic_launcher_foreground,R.drawable.ic_launcher_background,};
MyAdapter adapter = new MyAdapter(this,itemsarray);
binding.gvImages.setAdapter(adapter);
}
}
这是activity_main.xml,MainActivity.java类的xml文件。这里是我们设计的所有地方
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<GridView
android:id="@+id/gvImages"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:numColumns="auto_fit"
android:horizontalSpacing="10dp"
android:verticalSpacing="10dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
这个id grid_layout.xml,也就是这个xml文件,用于自定义grid view中的view
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:tools="http://schemas.android.com/tools">
<ImageView
android:id="@+id/imageView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scaleType="center"
tools:srcCompat="@tools:sample/avatars" />
</LinearLayout>```
*Thanks in advance*
解决方法
像这样更改您的 BaseAdapter 代码
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import com.aijishnu.baseadaptersample.databinding.GridLayoutBinding;
public class MyAdapter extends BaseAdapter {
Context c;
int items[];
MyAdapter(Context c,int arr[]) {
this.c = c;
items = arr;
}
@Override
public int getCount() {
return items.length;
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(int position,View convertView,ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
GridLayoutBinding itemBinding = GridLayoutBinding.inflate(LayoutInflater.from(parent.getContext()),parent,false);
holder = new ViewHolder(itemBinding);
holder.view = itemBinding.getRoot();
holder.view.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.binding.imageView.setImageResource(items[position]);
return holder.view;
}
private static class ViewHolder {
private View view;
private GridLayoutBinding binding;
ViewHolder(GridLayoutBinding binding) {
this.view = binding.getRoot();
this.binding = binding;
}
}
}