如何在RecyclerView中对整个内容进行缩放？
如何在RecyclerView中对整个内容进行缩放？
提问于 2016-07-05 11:26:03
我需要放大/缩小RecyclerView的全部内容。实际上，我需要根据宽度调整所有子视图的大小，并调整每个项中的文本大小。
public class ViewHolder {
Button btn;
...
}当用户进行缩放时，按钮的文本应该减少到8sp，如果用户继续放大，则会消失。
所以，现在我进退两难:我需要做什么？调整适配器中的项的大小，或在LayoutManager中调整它们的大小，并更新整个适配器。
这两种场景似乎都会影响视觉效果的表现，所以我需要帮助。也许你能给我一个更好的解决方案。
对于2016年11月21日的情况，我找不到任何解决方案。
因此，我决定写我自己的视图，并在每个缩放比例因子变化中重新测量可见视图。
回答 3
Stack Overflow用户
发布于 2016-11-21 10:51:02
您使用哪个适配器？
我尝试了水平LinearLayoutManager，并在适配器中调整了条目的大小：
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
...
final ViewGroup.LayoutParams layoutParams = viewHolder.rootView.getLayoutParams();
layoutParams.width = getItemWidth(position); //width calculation using current zoom level
layoutParams.height = mItemLayoutHeight;
viewHolder.rootView.setLayoutParams(layoutParams);
...和setZoom(..)活动/片段的方法如下所示：
public void setZoom(float newValue) {
int dScroll = (int) ((ADAPTER_ZOOM - newValue) * getResources().getDisplayMetrics().widthPixels/2f); //assume you Recycler view uses whole display
ADAPTER_ZOOM = newValue;
resetBoundaries();
//
epgAdapter.notifyDataSetChanged();
//
epgRecyclerView.scrollBy(dScroll, 0);
}但是，由于我的自定义LayoutManager性能很差，似乎在LinearLayoutManager中有一个优化列表。
Stack Overflow用户
发布于 2021-09-06 12:10:26
要全面实施，请参阅：
github.com/mosayeb-masoumi/zoom_whole_recyclerview
Stack Overflow用户
发布于 2017-06-07 06:01:01
使用此代码。它可以很好地放大回收视图的所有内容。
import android.content.Context;
import android.graphics.Canvas;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
/**
@author yogesh
* */
public class PinchRecyclerView extends RecyclerView {
private static final int INVALID_POINTER_ID = -1;
private int mActivePointerId = INVALID_POINTER_ID;
private ScaleGestureDetector mScaleDetector;
private float mScaleFactor = 1.f;
private float maxWidth = 0.0f;
private float maxHeight = 0.0f;
private float mLastTouchX;
private float mLastTouchY;
private float mPosX;
private float mPosY;
private float width;
private float height;
public PinchRecyclerView(Context context) {
super(context);
if (!isInEditMode())
mScaleDetector = new ScaleGestureDetector(getContext(), new ScaleListener());
}
public PinchRecyclerView(Context context, AttributeSet attrs) {
super(context, attrs);
if (!isInEditMode())
mScaleDetector = new ScaleGestureDetector(getContext(), new ScaleListener());
}
public PinchRecyclerView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
if (!isInEditMode())
mScaleDetector = new ScaleGestureDetector(getContext(), new ScaleListener());
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
width = MeasureSpec.getSize(widthMeasureSpec);
height = MeasureSpec.getSize(heightMeasureSpec);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
try {
return super.onInterceptTouchEvent(ev);
} catch (IllegalArgumentException ex) {
ex.printStackTrace();
}
return false;
}
@Override
public boolean onTouchEvent(@NonNull MotionEvent ev) {
super.onTouchEvent(ev);
final int action = ev.getAction();
mScaleDetector.onTouchEvent(ev);
switch (action & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN: {
final float x = ev.getX();
final float y = ev.getY();
mLastTouchX = x;
mLastTouchY = y;
mActivePointerId = ev.getPointerId(0);
break;
}
case MotionEvent.ACTION_MOVE: {
/* this line is replaced because here came below isssue
java.lang.IllegalArgumentException: pointerIndex out of range
ref http://stackoverflow.com/questions/6919292/pointerindex-out-of-range-android-multitouch
*/
//final int pointerIndex = ev.findPointerIndex(mActivePointerId);
final int pointerIndex = (action & MotionEvent.ACTION_POINTER_INDEX_MASK)
>> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
final float x = ev.getX(pointerIndex);
final float y = ev.getY(pointerIndex);
final float dx = x - mLastTouchX;
final float dy = y - mLastTouchY;
mPosX += dx;
mPosY += dy;
if (mPosX > 0.0f)
mPosX = 0.0f;
else if (mPosX < maxWidth)
mPosX = maxWidth;
if (mPosY > 0.0f)
mPosY = 0.0f;
else if (mPosY < maxHeight)
mPosY = maxHeight;
mLastTouchX = x;
mLastTouchY = y;
invalidate();
break;
}
case MotionEvent.ACTION_UP: {
mActivePointerId = INVALID_POINTER_ID;
break;
}
case MotionEvent.ACTION_CANCEL: {
mActivePointerId = INVALID_POINTER_ID;
break;
}
case MotionEvent.ACTION_POINTER_UP: {
final int pointerIndex = (action & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
final int pointerId = ev.getPointerId(pointerIndex);
if (pointerId == mActivePointerId) {
final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
mLastTouchX = ev.getX(newPointerIndex);
mLastTouchY = ev.getY(newPointerIndex);
mActivePointerId = ev.getPointerId(newPointerIndex);
}
break;
}
}
return true;
}
@Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.save(Canvas.MATRIX_SAVE_FLAG);
canvas.translate(mPosX, mPosY);
canvas.scale(mScaleFactor, mScaleFactor);
canvas.restore();
}
@Override
protected void dispatchDraw(@NonNull Canvas canvas) {
canvas.save(Canvas.MATRIX_SAVE_FLAG);
if (mScaleFactor == 1.0f) {
mPosX = 0.0f;
mPosY = 0.0f;
}
canvas.translate(mPosX, mPosY);
canvas.scale(mScaleFactor, mScaleFactor);
super.dispatchDraw(canvas);
canvas.restore();
invalidate();
}
private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
@Override
public boolean onScale(ScaleGestureDetector detector) {
mScaleFactor *= detector.getScaleFactor();
mScaleFactor = Math.max(1.0f, Math.min(mScaleFactor, 3.0f));
maxWidth = width - (width * mScaleFactor);
maxHeight = height - (height * mScaleFactor);
invalidate();
return true;
}
}
}摘自此StackOverflow答案的代码：Android change recycler view column no. on pinch zoom
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/38202268
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