Android 可拖拽的view，不影响下层点击，不影响子view点击

转载请注明原创出处，谢谢！

• GitHub: @Ricco

import android.annotation.SuppressLint;
import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.LinearLayout;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.customview.widget.ViewDragHelper;

public class MyViewDragLinearLayout extends LinearLayout {

    public MyViewDragLinearLayout(@NonNull Context context) {
        super(context);
        init();
    }

    public MyViewDragLinearLayout(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        init();
    }

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

    private ViewDragHelper mViewDragHelper;

    private void init() {
        mViewDragHelper = ViewDragHelper.create(this, 1.0f, new ViewDragHelper.Callback() {
            @Override
            public boolean tryCaptureView(@NonNull View child, int pointerId) {
                return true;
            }

            @Override
            public int clampViewPositionVertical(@NonNull View child, int top, int dy) {
                if (top <= 0) {
                    return 0;
                }
                return Math.min(top, getMeasuredHeight() - child.getMeasuredHeight());
            }

            @Override
            public int clampViewPositionHorizontal(@NonNull View child, int left, int dx) {
                if (left <= 0) {
                    return 0;
                }
                return Math.min(left, getMeasuredWidth() - child.getMeasuredWidth());
            }

            @Override
            public int getViewHorizontalDragRange(@NonNull View child) {
                return 1; // 返回1不影响子view的点击事件
            }

            @Override
            public int getViewVerticalDragRange(@NonNull View child) {
                return 1; // 返回1不影响子view的点击事件
            }
        });
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        return mViewDragHelper.shouldInterceptTouchEvent(ev);
    }

    @SuppressLint("ClickableViewAccessibility")
    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        mViewDragHelper.processTouchEvent(ev);
        // 判断触摸是否在子View的范围内，不影响底部view的时间
        return mViewDragHelper.isViewUnder(getChildAt(0), (int) ev.getX(), (int) ev.getY());
    }
}

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

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center">

        <Button
            android:id="@+id/btn4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="底层按钮" />
    </LinearLayout>

    <com.demo.MyViewDragLinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal">

        <LinearLayout
            android:id="@+id/ll"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="#afa"
            android:orientation="horizontal"
            android:padding="@dimen/dp_10">

            <Button
                android:id="@+id/btn1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="#faf"
                android:text="按钮1" />

            <Button
                android:id="@+id/btn2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="#aaf"
                android:text="按钮1" />

            <Button
                android:id="@+id/btn3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="#ffa"
                android:text="按钮3" />
        </LinearLayout>
    </com.demo.MyViewDragLinearLayout>
</FrameLayout>

如果需要设置ll的开始位置，动态设置LayoutParams的topMargin和leftMargin就可以