我构建了一个应用程序，其布局应与 WhatsApp 聊天 Activity 中使用的布局几乎相同。它应该有一个文本输入、相机和视频录制选项。项目应在回收器内居中，当数据集更改时，回收器应滚动到最后添加的项目。当用户单击 Editext 键盘时，应调整 View 大小，向上移动回收器并聚焦于数据集中的最后一项。
对于滚动部分，我使用了 SmoothScrollToPosiotion，但是当包含图像或视频的项目时， View 被切碎，自动滚动也会停止工作。一个奇怪的错误是，当我通过单击 editText 打开键盘时，回收器几乎滚动到最后一个项目，但不完全滚动，只有多次重新打开键盘时，它才会完全显示该项目。
已经尝试过在谷歌上找到的解决方案，但这里没有预期的结果:(
<小时/>编辑:几乎解决了，我刚刚将 SmoothScrollToposition 移动到每个按钮的 onClickListener 内。现在它不会滚动到最后一项，而是完全滚动到最后一项之前的项目:D
这里有一些代码: (如果需要完整代码，请访问https://github.com/MikeSys/ChatApp)
<小时/>主 Activity 布局
<android.support.constraint.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"
android:orientation="vertical"
tools:context=".MainActivity">
<android.support.v7.widget.RecyclerView
android:background="@drawable/sfondo"
android:id="@+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintBottom_toTopOf="@+id/linearLayout"
app:layout_constraintTop_toTopOf="parent"
/>
<LinearLayout
android:id="@+id/linearLayout"
android:layout_width="match_parent"
android:layout_height="55dp"
app:layout_constraintBottom_toBottomOf="parent"
android:orientation="horizontal">
<EditText
android:layout_gravity="center_vertical"
android:id="@+id/editText"
android:layout_width="255dp"
android:layout_height="55dp"
android:background="#0003A9F4"
android:hint="Scrivi"
android:padding="10dp" />
<Button
android:layout_gravity="center_vertical"
android:id="@+id/camera"
android:layout_width="50dp"
android:layout_height="50dp"
android:background="@drawable/camera"
/>
<Button
android:layout_gravity="center_vertical"
android:id="@+id/video"
android:layout_width="50dp"
android:layout_height="50dp"
android:background="@drawable/video"
/>
<Button
android:id="@+id/send"
android:layout_width="55dp"
android:layout_height="55dp"
android:background="@drawable/send" />
</LinearLayout>
</android.support.constraint.ConstraintLayout>
主要 Activity 代码
public class MainActivity extends AppCompatActivity {
private ArrayList<ModelloDati> dati = new ArrayList<>();
private LinearLayoutManager linearLayoutManager;
private static final String VIDEO_DIRECTORY = "/Chat";
private myAdapter adapter;
public Uri passUri;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Variables-----------------------------------------
final RecyclerView recyclerView = findViewById(R.id.recyclerView);
Button video = findViewById(R.id.video);
Button camera = findViewById(R.id.camera);
Button send = findViewById(R.id.send);
final EditText editText = findViewById(R.id.editText);
// Layout Manager------------------------------------------------
linearLayoutManager = new LinearLayoutManager(MainActivity.this);
linearLayoutManager.setReverseLayout(true);
recyclerView.setLayoutManager(linearLayoutManager);
// Adapter-----------------------------------------
if(dati.size()> 1){
adapter = new myAdapter(dati, this);
//Removed SmoothScroll form here
adapter.notifyDataSetChanged();
recyclerView.setAdapter(adapter);
}
else{
Collections.reverse(dati);
adapter = new myAdapter(dati,this);
recyclerView.setAdapter(adapter);
}
// Click Listener Video button---------------------------------------------
video.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);
startActivityForResult(intent,0);
//Added here SmotthScroll
recyclerView.smoothScrollToPosition(dati.size());
}
});
// Click Listener Camera button--------------------------------------------
camera.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent,1);
//Added here SmotthScroll
recyclerView.smoothScrollToPosition(dati.size());
}
});
// Click Listener Send button----------------------------------------------
send.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String string = editText.getText().toString();
dati.add(new ModelloDati(0,string));
editText.getText().clear();
//Added here SmotthScroll
recyclerView.smoothScrollToPosition(dati.size());
closeKeyboard();
}
});
}
private void closeKeyboard() {
View view = getCurrentFocus();
if(view != null){
InputMethodManager imm =
(InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(view.getWindowToken(),0);
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable
Intent data) {
super.onActivityResult(requestCode, resultCode, data);
switch (requestCode){
case 0:
try {
Uri contentURI = data.getData();
passUri = contentURI;
String recordedVideoPath = getPath(contentURI);
Log.d("frrr", recordedVideoPath);
saveVideoToInternalStorage(recordedVideoPath);
dati.add(new ModelloDati(2, contentURI));
}catch (Throwable o){Log.i("CAM","User aborted action");}
case 1:
try {
Bitmap bitmap = (Bitmap)data.getExtras().get("data");
dati.add(new ModelloDati(1,bitmap));
}catch(Throwable o){
Log.i("CAM","User aborted action");
}
}
}
private void saveVideoToInternalStorage (String filePath) {
File new file;
try {
File currentFile = new File(filePath);
File wallpaperDirectory = new
File(Environment.getExternalStorageDirectory() + VIDEO_DIRECTORY);
newfile = new File(wallpaperDirectory,
Calendar.getInstance().getTimeInMillis() + ".mp4");
if (!wallpaperDirectory.exists()) {
wallpaperDirectory.mkdirs();
}
if(currentFile.exists()){
InputStream in = new FileInputStream(currentFile);
OutputStream out = new FileOutputStream(newfile);
// Copy the bits from instream to outstream
byte[] buf = new byte[1024];
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
in.close();
out.close();
Log.v("vii", "Video file saved successfully.");
}else{
Log.v("vii", "Video saving failed. Source file missing.");
}
} catch (Exception e) {
e.printStackTrace();
}
}
public String getPath(Uri uri) {
String[] projection = { MediaStore.Video.Media.DATA };
Cursor cursor = getContentResolver().query(uri, projection, null, null,
null);
if (cursor != null) {
// HERE YOU WILL GET A NULLPOINTER IF CURSOR IS NULL
// THIS CAN BE, IF YOU USED OI FILE MANAGER FOR PICKING THE MEDIA
int column_index = cursor
.getColumnIndexOrThrow(MediaStore.Video.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
} else
return null;
}
}
最佳答案
通过在 onClickListerner 内移动 smoothScrollToPosition 来解决(视频/相机按钮我必须将其移动到 onActivityResult 内)。
<小时/>更新了主要内容
public class MainActivity extends AppCompatActivity {
private ArrayList<ModelloDati> dati = new ArrayList<>();
private LinearLayoutManager linearLayoutManager;
private static final String VIDEO_DIRECTORY = "/Chat";
private myAdapter adapter;
private RecyclerView recyclerView;
private VideoView videoView;
public Uri passUri;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Variables-----------------------------------------
recyclerView = findViewById(R.id.recyclerView);
Button video = findViewById(R.id.video);
Button camera = findViewById(R.id.camera);
Button send = findViewById(R.id.send);
final EditText editText = findViewById(R.id.editText);
// Layout Manager------------------------------------------------
linearLayoutManager = new LinearLayoutManager(MainActivity.this);
linearLayoutManager.setStackFromEnd(true);
RecyclerView.ItemAnimator itemAnimator = new DefaultItemAnimator();
recyclerView.setLayoutManager(linearLayoutManager);
recyclerView.setItemAnimator(itemAnimator);
// Adapter-----------------------------------------
//adapter.notifyDataSetChanged();
adapter = new myAdapter(dati, this);
recyclerView.setAdapter(adapter);
// Click Listener Video button----------------------------------------------
video.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);
startActivityForResult(intent,0);
}
});
// Click Listener Camera button----------------------------------------------
camera.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent,1);
}
});
// Click Listener Send button------------------------------------------------
send.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String string = editText.getText().toString();
dati.add(new ModelloDati(0,string));
adapter.notifyItemInserted(dati.size());
editText.getText().clear();
recyclerView.smoothScrollToPosition(dati.size());
closeKeyboard();
}
});
}
private void closeKeyboard() {
View view = getCurrentFocus();
if(view != null){
InputMethodManager imm =
(InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(view.getWindowToken(),0);
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data)
{
super.onActivityResult(requestCode, resultCode, data);
switch (requestCode){
case 0:
try {
Uri contentURI = data.getData();
passUri = contentURI;
String recordedVideoPath = getPath(contentURI);
saveVideoToInternalStorage(recordedVideoPath);
dati.add(new ModelloDati(2, contentURI));
adapter.notifyItemInserted(dati.size());
recyclerView.smoothScrollToPosition(dati.size());
}catch (Throwable o){Log.i("CAM","User aborted action");}
case 1:
try {
Bitmap bitmap = (Bitmap)data.getExtras().get("data");
dati.add(new ModelloDati(1,bitmap));
adapter.notifyItemInserted(dati.size());
recyclerView.smoothScrollToPosition(dati.size());
}catch(Throwable o){
Log.i("CAM","User aborted action");
}
}
}
private void saveVideoToInternalStorage (String filePath) {
File newfile;
try {
File currentFile = new File(filePath);
File wallpaperDirectory = new File(Environment.getExternalStorageDirectory() +
VIDEO_DIRECTORY);
newfile = new File(wallpaperDirectory, Calendar.getInstance().getTimeInMillis()
+ ".mp4");
if (!wallpaperDirectory.exists()) {
wallpaperDirectory.mkdirs();
}
if(currentFile.exists()){
InputStream in = new FileInputStream(currentFile);
OutputStream out = new FileOutputStream(newfile);
// Copy the bits from instream to outstream
byte[] buf = new byte[1024];
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
in.close();
out.close();
Log.v("vii", "Video file saved successfully.");
}else{
Log.v("vii", "Video saving failed. Source file missing.");
}
} catch (Exception e) {
e.printStackTrace();
}
}
public String getPath(Uri uri) {
String[] projection = { MediaStore.Video.Media.DATA };
Cursor cursor = getContentResolver().query(uri, projection, null, null, null);
if (cursor != null) {
// HERE YOU WILL GET A NULLPOINTER IF CURSOR IS NULL
// THIS CAN BE, IF YOU USED OI FILE MANAGER FOR PICKING THE MEDIA
int column_index = cursor
.getColumnIndexOrThrow(MediaStore.Video.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
} else
return null;
}
}
关于java - 如何制作像 WhatsApp 聊天 Activity 一样的 RecyclerView？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/56289702/