第二次做拖拽吸邊的功能了，但還是費(fèi)了不少時(shí)間蘑险，所以簡單記錄下！

拖拽待锈、吸邊.gif

1.參數(shù)：

    <declare-styleable name="MoveFrameLayout">
        <!--是否需要自動(dòng)吸邊-->
        <attr name="IsAttach" format="boolean" />
        <!--是否可拖曳-->
        <attr name="IsDrag" format="boolean" />
    </declare-styleable>

2.代碼：

package 包名.weight;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.OvershootInterpolator;
import android.widget.FrameLayout;

import com.blankj.utilcode.util.SizeUtils;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import 包名.R;

/**
 * Des: 拖拽漠其、自吸邊控件
 * Created by kele on 2021/1/6.
 * E-mail:984127585@qq.com
 */
public class MoveFrameLayout extends FrameLayout {

    public MoveFrameLayout(@NonNull Context context) {
        this(context, null);
    }

    public MoveFrameLayout(@NonNull Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public MoveFrameLayout(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        initAttrs(context, attrs);
    }

    private boolean isAttach;//是否自動(dòng)吸邊
    private boolean isDrag;//是否可拖動(dòng)

    /**
     * 初始化自定義屬性
     */
    private void initAttrs(Context context, AttributeSet attrs) {
        TypedArray mTypedAttay = context.obtainStyledAttributes(attrs, R.styleable.MoveFrameLayout);
        isAttach = mTypedAttay.getBoolean(R.styleable.MoveFrameLayout_IsAttach, true);
        isDrag = mTypedAttay.getBoolean(R.styleable.MoveFrameLayout_IsDrag, true);
        mTypedAttay.recycle();
    }

    private int mParentWidth = 0;//父控件的寬
    private int mParentHeight = 0;//父控件的高

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        //獲取父控件寬高
        ViewGroup mViewGroup = (ViewGroup) getParent();
        if (mViewGroup != null) {
            int[] location = new int[2];
            mViewGroup.getLocationOnScreen(location);
            //獲取父布局的高度
            mParentHeight = mViewGroup.getMeasuredHeight();
            mParentWidth = mViewGroup.getMeasuredWidth();
        }
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        //點(diǎn)擊點(diǎn)在控件區(qū)域內(nèi)，接受事件
        boolean inRangeOfView = inRangeOfView(this, ev);
        return inRangeOfView;
    }

    private float mLastX;//按下位置x
    private float mLastY;//按下位置Y
    private boolean isDrug = false;//是否是拖動(dòng)

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        if (isDrag) {
            //請求父控件將事件交由自己處理
            getParent().requestDisallowInterceptTouchEvent(true);
            float mX = ev.getX();
            float mY = ev.getY();
            switch (ev.getAction()) {
                case MotionEvent.ACTION_DOWN:
                    //重置拖動(dòng)狀態(tài)
                    isDrug = false;
                    //記錄按下的位置
                    mLastX = mX;
                    mLastY = mY;
                    break;
                case MotionEvent.ACTION_MOVE:
                    //手指X軸滑動(dòng)距離
                    float differenceValueX = mX - mLastX;
                    //手指Y軸滑動(dòng)距離
                    float differenceValueY = mY - mLastY;
                    //判斷是否為拖動(dòng)操作
                    if (!isDrug) {
                        if (Math.sqrt(differenceValueX * differenceValueX + differenceValueY * differenceValueY) < 2) {
                            isDrug = false;
                        } else {
                            isDrug = true;
                        }
                    }
                    //獲取手指按下的距離與控件本身X軸的距離
                    float ownX = getX();
                    //獲取手指按下的距離與控件本身Y軸的距離
                    float ownY = getY();
                    //理論中X軸拖動(dòng)的距離
                    float endX = ownX + differenceValueX;
                    //理論中Y軸拖動(dòng)的距離
                    float endY = ownY + differenceValueY;
                    //X軸可以拖動(dòng)的最大距離
                    float maxX = mParentWidth - getWidth();
                    //Y軸可以拖動(dòng)的最大距離
                    float maxY = mParentHeight - getHeight() - SizeUtils.dp2px(getPaddingBottom() + 15);
                    //X軸邊界限制---這里對X軸拖動(dòng)不做限制
                    //endX = endX < 0 ? 0 : endX > maxX ? maxX : endX;
                    //Y軸邊界限制
                    endY = endY < 0 ? 0 : endY > maxY ? maxY : endY;
                    //開始移動(dòng)
                    setX(endX);
                    setY(endY);
                    break;
                case MotionEvent.ACTION_UP:
                    //根據(jù)自定義屬性判斷是否需要貼邊
                    if (isAttach) {
                        //判斷是否為點(diǎn)擊事件
                        float center = mParentWidth / 2;
                        //自動(dòng)貼邊
                        if (ev.getRawX() <= center) {
                            //向左貼邊
                            animate()
                                    //.setInterpolator(new BounceInterpolator())
                                    .setInterpolator(new OvershootInterpolator())
                                    .setDuration(400)
                                    .x(SizeUtils.dp2px(0))
                                    .start();
                        } else {
                            //向右貼邊
                            animate()
                                    .setInterpolator(new OvershootInterpolator())
                                    .setDuration(400)
                                    .x(mParentWidth - getWidth() - SizeUtils.dp2px(0))
                                    .start();
                        }
                    }
                    break;
            }
        }
        return isDrug ? true : super.onTouchEvent(ev);
    }

    /**
     * 點(diǎn)擊點(diǎn)是否在控件區(qū)域
     *
     * @param view
     * @param ev
     * @return
     */
    private boolean inRangeOfView(View view, MotionEvent ev) {
        Rect rect = new Rect();
        view.getGlobalVisibleRect(rect);
        int rawX = (int) ev.getRawX();
        int rawY = (int) ev.getRawY();
        if (rect.contains(rawX, rawY)) {
            return true;
        }
        return false;
    }
}

3.使用：

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:paddingBottom="@dimen/dp_50"
    android:layout_height="match_parent">

    <包名.weight.MoveFrameLayout
        android:id="@+id/mfl_fb"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|right"
        app:IsAttach="true"
        app:IsDrag="true"
        android:layout_marginBottom="@dimen/dp_50"
        android:padding="@dimen/dp_12">

        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/ic_fb" />
    </包名.weight.MoveFrameLayout>
</FrameLayout>

拖動(dòng)控件添加縮放功能

在上述MoveFrameLayout 類中添加方法和變量

    private boolean isScaled;//是否已經(jīng)放大
    private AnimatorSet mAnimatorSet;//動(dòng)畫集合

    /**
     * 執(zhí)行動(dòng)畫
     *
     * @param valueFrom
     * @param valueTo
     * @param duration
     */
    private void startScaleAnimator(float valueFrom, float valueTo, int duration) {
        ObjectAnimator scaleX = ObjectAnimator.ofFloat(this, "scaleX", valueFrom, valueTo);
        ObjectAnimator scaleY = ObjectAnimator.ofFloat(this, "scaleY", valueFrom, valueTo);
        if (null == mAnimatorSet) {
            mAnimatorSet = new AnimatorSet();
        }
        mAnimatorSet.play(scaleX).with(scaleY);
        mAnimatorSet.setDuration(duration);
        mAnimatorSet.start();
    }

在上述MoveFrameLayout-onTouchEvent();中添加代碼：

            switch (ev.getAction()) {
                case MotionEvent.ACTION_DOWN:
                    //...
                    isScaled = false;
                    break;
                case MotionEvent.ACTION_MOVE:
                    //...
                    if (isDrug && !isScaled) {
                        //放大動(dòng)畫
                        startScaleAnimator(1.0f, 1.1f, 300);
                        //Animator scaleAnimator = AnimatorInflater.loadAnimator(getContext(), R.animator.anim_scale_up);
                        //scaleAnimator.setTarget(this);
                        //scaleAnimator.start();
                        isScaled = true;
                    }
                    break;
                case MotionEvent.ACTION_UP:
                    //...
                    if (isScaled) {
                        //縮小動(dòng)畫
                        startScaleAnimator(1.1f, 1.0f, 300);
                        //Animator scaleAnimator = AnimatorInflater.loadAnimator(getContext(), R.animator.anim_scale_down);
                        //scaleAnimator.setTarget(this);
                        //scaleAnimator.start();
                        isScaled = false;
                    }
                    break;
            }