15
Próbuję użyć RecyclerView i GridLayoutManager zrobić siatkę 3 kolumny i używam ItemDecoration aby odstępy między kolumnami, teraz problemem jest pozycja na szerokość w trzeciej kolumnie jest mniejsza niż w pierwszej i drugiej kolumnie! Zobacz zrzut ekranu poniżej.przedmioty nie są tej samej szerokości przy użyciu RecyclerView GridLayoutManager aby odstępy kolumny ItemDecoration
Gdybym nie dodawać zwyczaj ItemDecoration do RecyclerView, wszystko jest OK.
Oto mój kod:
MainActivity.java:
public class MainActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
private MyAdapter mAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mRecyclerView = (RecyclerView) findViewById(R.id.recycler_view);
mAdapter = new MyAdapter();
mRecyclerView.setAdapter(mAdapter);
GridLayoutManager gridLayoutManager = new GridLayoutManager(this, 3);
mRecyclerView.setLayoutManager(gridLayoutManager);
int horizontalSpacing = 20;
int verticalSpacing = 10;
SpacingDecoration decoration = new SpacingDecoration(horizontalSpacing, verticalSpacing, true);
mRecyclerView.addItemDecoration(decoration);
}
private static class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private int[] mColors = new int[]{Color.RED, Color.BLUE, Color.MAGENTA};
private static class ItemHolder extends RecyclerView.ViewHolder {
public MyTextView title;
public ItemHolder(View itemView) {
super(itemView);
title = (MyTextView) itemView.findViewById(android.R.id.text1);
title.setTextColor(Color.WHITE);
}
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item, parent, false);
ItemHolder holder = new ItemHolder(itemView);
holder.itemView.setOnClickListener(itemClickListener);
return holder;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder rHolder, int position) {
ItemHolder holder = (ItemHolder) rHolder;
holder.title.setText(String.format("[%d]width:%d", position, holder.itemView.getWidth()));
holder.itemView.setBackgroundColor(mColors[position % mColors.length]);
holder.itemView.setTag(position);
holder.title.setTag(position);
}
@Override
public int getItemCount() {
return 50;
}
private View.OnClickListener itemClickListener = new View.OnClickListener() {
@Override
public void onClick(View v) {
int position = (int) v.getTag();
showText(v.getContext(), String.format("[%d]->width:%d", position, v.getWidth()));
}
};
}
public static class SpacingDecoration extends RecyclerView.ItemDecoration {
private int mHorizontalSpacing = 5;
private int mVerticalSpacing = 5;
private boolean isSetMargin = true;
public SpacingDecoration(int hSpacing, int vSpacing, boolean setMargin) {
isSetMargin = setMargin;
mHorizontalSpacing = hSpacing;
mVerticalSpacing = vSpacing;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
boolean isSetMarginLeftAndRight = this.isSetMargin;
int bottomOffset = mVerticalSpacing;
int leftOffset = 0;
int rightOffset = 0;
RecyclerView.LayoutParams lp = (RecyclerView.LayoutParams) view.getLayoutParams();
if (parent.getLayoutManager() instanceof GridLayoutManager) {
GridLayoutManager lm = (GridLayoutManager) parent.getLayoutManager();
GridLayoutManager.LayoutParams gridLp = (GridLayoutManager.LayoutParams) lp;
if (gridLp.getSpanSize() == lm.getSpanCount()) {
// Current item is occupied the whole row
// We just need to care about margin left and right now
if (isSetMarginLeftAndRight) {
leftOffset = mHorizontalSpacing;
rightOffset = mHorizontalSpacing;
}
} else {
// Current item isn't occupied the whole row
if (gridLp.getSpanIndex() > 0) {
// Set space between items in one row
leftOffset = mHorizontalSpacing;
} else if (gridLp.getSpanIndex() == 0 && isSetMarginLeftAndRight) {
// Set left margin of a row
leftOffset = mHorizontalSpacing;
}
if (gridLp.getSpanIndex() == lm.getSpanCount() - gridLp.getSpanSize() && isSetMarginLeftAndRight) {
// Set right margin of a row
rightOffset = mHorizontalSpacing;
}
}
}
outRect.set(leftOffset, 0, rightOffset, bottomOffset);
}
}
private static Toast sToast;
public static void showText(Context context, String text) {
if (sToast != null) {
sToast.cancel();
}
sToast = Toast.makeText(context, text, Toast.LENGTH_LONG);
sToast.show();
}
}
activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
android:id="@+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</RelativeLayout>
item.xml
<?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"
android:orientation="vertical">
<com.example.liuqing.rvgldemo.MyTextView
android:id="@android:id/text1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="5dp"
android:textColor="#ffffff"
android:textAppearance="?android:attr/textAppearanceMedium"/>
</LinearLayout>
MyTextView.java
public class MyTextView extends TextView {
public MyTextView(Context context) {
super(context);
}
public MyTextView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public MyTextView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@Override
public void onWindowFocusChanged(boolean hasWindowFocus) {
super.onWindowFocusChanged(hasWindowFocus);
if (hasWindowFocus) {
setText("[" + getTag() + "]width:" + getWidth());
}
}
}
Będzie to bardzo ważne, jeśli ktoś może wyjaśnić ten problem.
W swojej formule '+ 1 'w prawym marginesie rzeczywistości nie jest' + 1', powinno być '+ spanSize z cell'. (możesz pobrać rozmiar span za pomocą spanSizeLookup lub w LayoutParams komórki) – pdegand59