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我開始認爲缺乏OpenGL我不能拖動一個簡單的視圖。說真的，我已經閱讀了10-15個教程來拖拽視圖，並且每個教程都會向您展示如何將drawable拖拽到視圖中，或者拖拽imageview中的圖像（通過矩陣轉換）。但是沒有任何教程告訴你如何在超級視圖中拖動一個簡單的視圖。它真的很簡單。我有一個超級視圖，我添加可以說10個子視圖。無論我的手指觸碰到什麼，我爲iOS http://www.facebook.com/MakeASnowman製作了一個應用程序（任何一天都會點擊應用商店），並試圖爲Android構建它。但是沒有簡單的方法來做iOS中那麼簡單的事情（雙指旋轉，拖動視圖等）。這就是我想要的：我有一個自定義視圖，可以在其畫布上繪製圖像。然後，我將這些自定義視圖中的一個或多個實例化到「超級視圖」上。我可以拖拽/操作這些視圖（意思是我不翻譯這些視圖中的可繪畫，而是實際的視圖本身）。Android在一個超級視圖上拖動很多視圖
這裏是我的代碼，有正確的操作，但它執行視圖中繪製的他們：
package com.spentaklabs.view;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
public class MAView extends View
{
Drawable image;
private String imgName;
private float mPosX;
private float mPosY;
private float mLastTouchX;
private float mLastTouchY;
private static final int INVALID_POINTER_ID = -1;
private int mActivePointerId = INVALID_POINTER_ID;
private ScaleGestureDetector mScaleDetector;
private float mScaleFactor = 1.f;
public MAView(Context context)
{
super(context);
}
public MAView(Context context,String imgName)
{
this(context);
this.imgName = imgName;
image = context.getResources().getDrawable(R.drawable.hatshairears0);
image.setBounds(0, 0, image.getIntrinsicWidth(), image.getIntrinsicHeight());
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
}
public MAView(Context context, AttributeSet attrs, int defStyle)
{
super(context,attrs,defStyle);
}
@Override
public void onDraw(Canvas canvas)
{
canvas.save();
canvas.translate(mPosX, mPosY);
canvas.scale(mScaleFactor, mScaleFactor);
image.draw(canvas);
canvas.restore();
}
@Override
public boolean onTouchEvent(MotionEvent ev)
{
mScaleDetector.onTouchEvent(ev);
final int action = ev.getAction();
switch (action)
{
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:
{
// Extract the index of the pointer that left the touch sensor
final int pointerIndex = (action & MotionEvent.ACTION_POINTER_ID_MASK) >> MotionEvent.ACTION_POINTER_ID_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;
}
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;
}
}
}
我很想嘗試一下。在你的例子中，你僅僅使用一個列表來保存正在實例化的項目？ – spentak
正確，您可以拖動這些項目。我只是把一張圖片和一些文本放在那裏，以確保它能正常工作... – Matthieu
我把apk放在那裏：http://dl.dropbox.com/u/44437318/DragActivity-debug.apk所以你可以試試它看看它是否做你期望 – Matthieu