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我正在嘗試製作一個應用程序,用戶單擊圖像。 點擊圖片後,會出現3個矩形,可以根據圖片中的文字進行移動和調整大小。Android中的可調整大小的矩形覆蓋
所以我的問題是如何使這3個矩形在視圖從圖像的一部分選擇文本
請幫我做出這個問題
我正在嘗試製作一個應用程序,用戶單擊圖像。 點擊圖片後,會出現3個矩形,可以根據圖片中的文字進行移動和調整大小。Android中的可調整大小的矩形覆蓋
所以我的問題是如何使這3個矩形在視圖從圖像的一部分選擇文本
請幫我做出這個問題
它不正是你想要的解決方案,但這個例子顯示如何繪製一個單一的矩形超過ImageView
和縮放/移動它:
public class OverlayImageView extends ImageView {
private static final int INVALID_POINTER_ID = -1;
private float mPosX;
private float mPosY;
private float mLastTouchX;
private float mLastTouchY;
private int mActivePointerId = INVALID_POINTER_ID;
private ScaleGestureDetector mScaleDetector;
private float mScaleFactor = 1.f;
private Rect mInitialRect;
private Paint mDrawPaint;
public OverlayImageView(Context context) {
this(context, null, 0);
}
public OverlayImageView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public OverlayImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
mDrawPaint = new Paint();
mDrawPaint.setColor(Color.RED);
mDrawPaint.setStyle(Paint.Style.STROKE);
mDrawPaint.setStrokeWidth(5);
mInitialRect = new Rect(10, 10, 100, 100);
}
@Override
public boolean onTouchEvent(@NonNull MotionEvent ev) {
// Let the ScaleGestureDetector inspect all events.
mScaleDetector.onTouchEvent(ev);
final int action = ev.getAction();
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: {
final int pointerIndex = ev.findPointerIndex(mActivePointerId);
final float x = ev.getX(pointerIndex);
final float y = ev.getY(pointerIndex);
// Only move if the ScaleGestureDetector isn't processing a gesture.
if (!mScaleDetector.isInProgress()) {
final float dx = x - mLastTouchX;
final float dy = y - mLastTouchY;
mPosX += dx;
mPosY += dy;
invalidate();
}
mLastTouchX = x;
mLastTouchY = y;
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 = (ev.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK)
>> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
final int pointerId = ev.getPointerId(pointerIndex);
if (pointerId == mActivePointerId) {
// This was our active pointer going up. Choose a new
// active pointer and adjust accordingly.
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(@NonNull Canvas canvas) {
super.onDraw(canvas);
canvas.save();
canvas.translate(mPosX, mPosY);
canvas.scale(mScaleFactor, mScaleFactor);
canvas.drawRect(mInitialRect, mDrawPaint);
canvas.restore();
}
private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
@Override
public boolean onScale(ScaleGestureDetector detector) {
mScaleFactor *= detector.getScaleFactor();
// Don't let the object get too small or too large.
mScaleFactor = Math.max(0.1f, Math.min(mScaleFactor, 10.0f));
invalidate();
return true;
}
}
}
感謝您的幫助。我已經做了矩形,但我想要三個矩形可聚焦,當我試圖添加這些矩形一個是可以聚焦和其他兩個不能正常工作。幫助,如何添加兩個可調整大小的矩形。 – Corrupt
@Corrupt你可以存儲矩形的數組,並在onTouchEvent中檢測哪一個位於MotionEvent中。在onDraw方法中繪製每個矩形縮放。 – Oleksandr