我最近实现了 Android 开发者网站上提供的拖动和缩放代码 FOUND HERE
我遇到的问题是关于将 View 添加到布局后移动 View 的能力。图像可通过手势缩放，但不可移动。
如果有帮助，这个 View 将被添加到 Fragment 中的 FrameLayout。
有没有人遇到过在自定义 View 中实现这个 Android 示例的类似问题？或者有人可以告诉我我错过了什么，我无法移动我正在添加的 View 。
public class CustomImageView extends View {
private static final int INVALID_POINTER_ID = 0;
Drawable _drawable;
// private static readonly int InvalidPointerId = -1;
// private int _activePointerId = InvalidPointerId;
private float _posX;
private float _posY;
private float mScaleFactor = 1.0f;
private int mActivePointerId = INVALID_POINTER_ID;
// gesture listeners
private ScaleGestureDetector mScaleDetector;
private float mLastTouchX;
private float mLastTouchY;
private float mPosY;
private float mPosX;
public CustomImageView(Context context, int resourceId) {
super(context, null, 0);
_drawable = getResources().getDrawable(resourceId);
_drawable.setBounds(0, 0, 200, 200);
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
// TODO Auto-generated constructor stub
}
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.save();
canvas.translate(_posX, _posY);
canvas.scale(mScaleFactor, mScaleFactor);
_drawable.draw(canvas);
canvas.restore();
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
// Let the ScaleGestureDetector inspect all events.
mScaleDetector.onTouchEvent(ev);
final int action = MotionEventCompat.getActionMasked(ev);
switch (action) {
case MotionEvent.ACTION_DOWN: {
final int pointerIndex = MotionEventCompat.getActionIndex(ev);
final float x = MotionEventCompat.getX(ev, pointerIndex);
final float y = MotionEventCompat.getY(ev, pointerIndex);
// Remember where we started (for dragging)
mLastTouchX = x;
mLastTouchY = y;
// Save the ID of this pointer (for dragging)
mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
break;
}
case MotionEvent.ACTION_MOVE: {
// Find the index of the active pointer and fetch its position
final int pointerIndex = MotionEventCompat.findPointerIndex(ev,
mActivePointerId);
final float x = MotionEventCompat.getX(ev, pointerIndex);
final float y = MotionEventCompat.getY(ev, pointerIndex);
// Calculate the distance moved
final float dx = x - mLastTouchX;
final float dy = y - mLastTouchY;
mPosX += dx;
mPosY += dy;
invalidate();
// Remember this touch position for the next move event
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 = MotionEventCompat.getActionIndex(ev);
final int pointerId = MotionEventCompat.getPointerId(ev,
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 = MotionEventCompat.getX(ev, newPointerIndex);
mLastTouchY = MotionEventCompat.getY(ev, newPointerIndex);
mActivePointerId = MotionEventCompat.getPointerId(ev,
newPointerIndex);
}
break;
}
}
return true;
}
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, 5.0f));
invalidate();
return true;
}
}
这是 XML，我要将 View 添加到的 root_layout 是一个 FrameLayout
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:clickable="true" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="@dimen/ab_height"
android:background="@color/red" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<ImageButton
android:id="@+id/btn_Back"
android:layout_width="@dimen/width"
android:layout_height="fill_parent"
android:background="@color/red"
android:contentDescription="@string/desc"
android:src="@drawable/ic_navigation_back" />
<LinearLayout
android:layout_width="@dimen/dim_1"
android:layout_height="fill_parent"
android:background="@color/red" >
</LinearLayout>
<TextView
android:id="@+id/text_name"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:ellipsize="end"
android:gravity="center"
android:singleLine="true"
android:tag="bold"
android:text="Pixagram"
android:textColor="@color/white"
android:textSize="@dimen/tex_size_xxxlarge"
android:textStyle="bold" />
<LinearLayout
android:layout_width="@dimen/dim_1"
android:layout_height="fill_parent"
android:background="@color/red" >
</LinearLayout>
<ImageButton
android:id="@+id/btn_Accept"
android:layout_width="@dimen/width"
android:layout_height="fill_parent"
android:background="@color/red"
android:contentDescription="@string/desc"
android:src="@drawable/ic_navigation_accept" />
</LinearLayout>
</RelativeLayout>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="@dimen/dim_1"
android:background="@color/red" >
</LinearLayout>
<FrameLayout
android:id="@+id/root_layout"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1" >
<ImageView
android:id="@+id/imageViewEdit"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="@drawable/abc_ab_solid_dark_holo" />
</FrameLayout>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="50dp"
android:background="@color/red"
android:orientation="horizontal" >
<HorizontalScrollView
android:id="@+id/horizontalScrollView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_gravity="bottom"
android:gravity="bottom"
android:background="@color/transparent" >
<LinearLayout
android:id="@+id/linearLayout1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal"
android:background="@color/transparent" >
<ImageButton
android:id="@+id/imageButton1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/abc_ic_clear" />
<ImageButton
android:id="@+id/imageButton2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/abc_tab_selected_pressed_holo" />
<ImageButton
android:id="@+id/imageButton3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/abc_ic_clear" />
<ImageButton
android:id="@+id/imageButton4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/abc_tab_selected_pressed_holo" />
<ImageButton
android:id="@+id/imageButton5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/abc_ic_clear" />
<ImageButton
android:id="@+id/imageButton6"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/abc_tab_selected_pressed_holo" />
<ImageButton
android:id="@+id/imageButton7"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/abc_ic_clear" />
<ImageButton
android:id="@+id/imageButton8"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/abc_tab_selected_pressed_holo" />
<ImageButton
android:id="@+id/imageButton9"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/abc_ic_clear" />
<ImageButton
android:id="@+id/imageButton10"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/abc_tab_selected_pressed_holo" />
</LinearLayout>
</HorizontalScrollView>
</LinearLayout>
</LinearLayout>
这似乎表明 ACTION_MOVE 没有被调用
09-23 23:14:46.310: I/ViewRootImpl(24235): ViewRoot's Touch Event : Touch Down
09-23 23:14:46.350: I/ViewRootImpl(24235): ViewRoot's Touch Event : Touch UP
09-23 23:14:47.300: I/ViewRootImpl(24235): ViewRoot's Touch Event : Touch Down
09-23 23:14:47.790: I/ViewRootImpl(24235): ViewRoot's Touch Event : Touch UP
09-23 23:14:48.000: I/ViewRootImpl(24235): ViewRoot's Touch Event : Touch Down
09-23 23:14:48.030: I/ViewRootImpl(24235): ViewRoot's Touch Event :261
09-23 23:14:48.670: I/ViewRootImpl(24235): ViewRoot's Touch Event :6
09-23 23:14:48.710: I/ViewRootImpl(24235): ViewRoot's Touch Event : Touch UP
09-23 23:14:48.980: I/ViewRootImpl(24235): ViewRoot's Touch Event : Touch Down
09-23 23:14:49.320: I/ViewRootImpl(24235): ViewRoot's Touch Event : Touch UP
最佳答案
虽然我没有仔细研究你的所有代码，但在你的 onDraw() 方法中，你似乎正在通过 _posX 和 进行翻译_posY，但您不会在手势处理的任何地方更改这些。尝试在 onDraw() 中使用 mPosX 和 mPosY。
关于android - 自定义View不随手势移动，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/26001426/