我需要在我的Android应用程序中实现一个水平列表视图。我做了一些研究,遇到了如何在Android中创建一个水平的ListView ?和横向列表视图在Android?然而,这些问题是在Recyclerview发布之前提出的。有没有更好的方法来实现这个现在与Recyclerview?
当前回答
如果你想使用RecyclerView和GridLayoutManager,这是实现水平滚动的方法。
recyclerView.setLayoutManager(
new GridLayoutManager(recyclerView.getContext(), rows, GridLayoutManager.HORIZONTAL, false));
其他回答
有没有更好的方法来实现这个现在与RecyclerView现在?
Yes.
当您使用RecyclerView时,您需要指定一个LayoutManager,该LayoutManager负责布局视图中的每个项。LinearLayoutManager允许你指定一个方向,就像一个正常的LinearLayout一样。
要用RecyclerView创建一个水平列表,你可以这样做:
LinearLayoutManager layoutManager
= new LinearLayoutManager(requireContext(), LinearLayoutManager.HORIZONTAL, false);
RecyclerView myList = (RecyclerView) findViewById(R.id.my_recycler_view);
myList.setLayoutManager(layoutManager);
您可以在代码或布局xml文件中更改方向。
在xml文件中
在你的布局xml文件中,将orientation设置为水平,layoutManager设置为LinearLayoutManager, GridLayoutManager, StaggeredGridLayoutManager之一。根据您的要求选择。
<androidx.recyclerview.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager" />
在代码中
如果希望以编程方式更改方向,请将layoutManager设置为水平方向。
recyclerView.layoutManager = LinearLayoutManager(context, RecyclerView.HORIZONTAL, false)
有一个名为HorizontalGridView的RecyclerView子类。你可以用它来表示水平方向。 垂直方向的VerticalGridView。
水平动态回收视图。
回收器视图实现
RecyclerView musicList = findViewById(R.id.MusicList);
// RecyclerView musiclist = findViewById(R.id.MusicList1);
// RecyclerView musicLIST = findViewById(R.id.MusicList2);
LinearLayoutManager layoutManager = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
musicList.setLayoutManager(layoutManager);
String[] names = {"RAP", "CH SHB", "Faheem", "Anum", "Shoaib", "Laiba", "Zoki", "Komal", "Sultan","Mansoob Gull"};
musicList.setAdapter(new ProgrammingAdapter(names));'
回收器视图的适配器类,其中有一个视图持有者用于持有该回收器的视图
public class ProgrammingAdapter
extendsRecyclerView.Adapter<ProgrammingAdapter.programmingViewHolder> {
private String[] data;
public ProgrammingAdapter(String[] data)
{
this.data = data;
}
@Override
public programmingViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
View view = inflater.inflate(R.layout.list_item_layout, parent, false);
return new programmingViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull programmingViewHolder holder, int position) {
String title = data[position];
holder.textV.setText(title);
}
@Override
public int getItemCount() {
return data.length;
}
public class programmingViewHolder extends RecyclerView.ViewHolder{
ImageView img;
TextView textV;
public programmingViewHolder(View itemView) {
super(itemView);
img = itemView.findViewById(R.id.img);
textV = itemView.findViewById(R.id.textt);
}
}
XML文件
<HorizontalScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.RecyclerView
android:id="@+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:scrollbars="vertical|horizontal" />
</HorizontalScrollView>
Code
import androidx.appcompat.app.AppCompatActivity;
import android.content.Context;
import android.content.ContextWrapper;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.widget.ImageView;
import android.widget.Toast;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
public class MainActivity extends AppCompatActivity{
ImageView mImageView1;
Bitmap bitmap;
String mSavedInfo;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mImageView1 = (ImageView) findViewById(R.id.image);
}
public Bitmap getBitmapFromURL(String src) {
try {
java.net.URL url = new java.net.URL(src);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(input);
return myBitmap;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
public void button2(View view) {
new DownloadImageFromTherad().execute();
}
private class DownloadImageFromTherad extends AsyncTask<String, Integer, String> {
@Override
protected String doInBackground(String... params) {
bitmap = getBitmapFromURL("https://cdn.pixabay.com/photo/2016/08/08/09/17/avatar-1577909_960_720.png");
return null;
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
File sdCardDirectory = Environment.getExternalStorageDirectory();
File image = new File(sdCardDirectory, "test.png");
boolean success = false;
FileOutputStream outStream;
mSavedInfo = saveToInternalStorage(bitmap);
if (success) {
Toast.makeText(getApplicationContext(), "Image saved with success", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getApplicationContext(), "Error during image saving" + mSavedInfo, Toast.LENGTH_LONG).show();
}
}
}
private String saveToInternalStorage(Bitmap bitmapImage) {
ContextWrapper cw = new ContextWrapper(getApplicationContext());
// path to /data/data/yourapp/app_data/imageDir
File directory = cw.getDir("imageDir", Context.MODE_PRIVATE);
File mypath = new File(directory, "profile.jpg");
FileOutputStream fos = null;
try {
fos = new FileOutputStream(mypath);
bitmapImage.compress(Bitmap.CompressFormat.PNG, 100, fos);
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return directory.getAbsolutePath();
}
private void loadImageFromStorage(String path) {
try {
File f = new File(path, "profile.jpg");
Bitmap b = BitmapFactory.decodeStream(new FileInputStream(f));
mImageView1.setImageBitmap(b);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
public void showImage(View view) {
loadImageFromStorage(mSavedInfo);
}
}
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