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Android View拖拽/拖放DragAndDrop自定义View.DragShadowBuilder，Kotlin（2）

news 2025/9/13 17:57:31

Android View拖拽/拖放DragAndDrop自定义View.DragShadowBuilder，Kotlin（2）

import android.graphics.Canvas
import android.graphics.Point
import android.graphics.drawable.ColorDrawable
import android.os.Bundle
import android.util.Log
import android.view.DragEvent
import android.view.View
import android.view.View.OnDragListener
import android.view.View.OnLongClickListener
import android.widget.ImageView
import androidx.appcompat.app.AppCompatActivity
import androidx.core.content.ContextCompatclass MainActivity : AppCompatActivity() {private val TAG = "fly"override fun onCreate(savedInstanceState: Bundle?) {super.onCreate(savedInstanceState)setContentView(R.layout.activity_main)val imageView = findViewById<ImageView>(R.id.image)imageView.setOnLongClickListener(object : OnLongClickListener {//长按事件触发拖拽override fun onLongClick(v: View?): Boolean {Log.d(TAG, "onLongClick")val builder = MyDragShadowBuilder(imageView)imageView.startDragAndDrop(null,builder,null,0)return true}})imageView.setOnDragListener(object : OnDragListener {override fun onDrag(v: View?, event: DragEvent?): Boolean {when (event?.action) {DragEvent.ACTION_DRAG_STARTED -> Log.d(TAG, "DragEvent.ACTION_DRAG_STARTED")DragEvent.ACTION_DRAG_ENTERED -> Log.d(TAG, "DragEvent.ACTION_DRAG_ENTERED")DragEvent.ACTION_DRAG_ENDED -> Log.d(TAG, "DragEvent.ACTION_DRAG_ENDED")}return true}})}class MyDragShadowBuilder(private var imageView: ImageView) : View.DragShadowBuilder() {//自定义绘制一个拖放时显示的阴影色块private val shadow = ColorDrawable(ContextCompat.getColor(imageView.context,android.R.color.holo_green_light))override fun onProvideShadowMetrics(outShadowSize: Point?, outShadowTouchPoint: Point?) {val width: Int = imageView.width * 2val height: Int = imageView.height * 2shadow.setBounds(0, 0, width, height)//拖动图像的宽和高outShadowSize?.set(width, height)//手指在拖动图像的位置 中点outShadowTouchPoint?.set(width / 2, height / 2)}override fun onDrawShadow(canvas: Canvas) {shadow.draw(canvas)}}
}

Android View拖拽startDragAndDrop，Kotlin-CSDN博客一个Android手势缩放图片的工具类；Android DynamicGrid：拖曳交换位置Android DynamicGrid是一个第三方开源项目，DynamicGrid在github上的项目主页是：https://github.com/askerov/DynamicGrid它实现在一个网格布局内，拖曳任意子view实现动态的交换位置，这很类似手机的桌面，手机桌面的图标，均可自由拖曳实现摆放位置的交换，如动图所示：_android 拖拽交换位置。但是还有一些遗漏问题尚未解决：垂直方向的拖曳。https://blog.csdn.net/zhangphil/article/details/133994955