Android拖放startDragAndDrop拖拽onDrawShadow动态添加View，Kotlin（3）

旧城等待， 2024-02-21 11:48 33阅读 0赞

### Android拖放startDragAndDrop拖拽onDrawShadow动态添加View，Kotlin（3） ###

import android.content.ClipData
    import android.graphics.Canvas
    import android.graphics.Point
    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.FrameLayout
    import android.widget.ImageView
    import androidx.appcompat.app.AppCompatActivity
    import androidx.core.content.ContextCompat
    
    class 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)
    
            val builder = MyDragShadowBuilder(imageView)
            imageView.setOnLongClickListener(object : OnLongClickListener {
                //长按事件触发拖拽
                override fun onLongClick(v: View?): Boolean {
                    Log.d(TAG, "onLongClick")
    
                    val data = ClipData.newPlainText("name", "phil")
                    imageView.startDragAndDrop(
                        data,
                        builder,
                        null,
                        0 or View.DRAG_FLAG_GLOBAL or View.DRAG_FLAG_OPAQUE
                    )
    
                    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 mView: View) :
            View.DragShadowBuilder() {
    
            override fun onProvideShadowMetrics(outShadowSize: Point?, outShadowTouchPoint: Point?) {
                val width: Int = mView.width * 2
                val height: Int = mView.height * 2
    
                //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) {
                val width: Int = mView.width * 2
                val height: Int = mView.height * 2
    
                val image = ImageView(mView.context)
                image.setImageResource(android.R.drawable.stat_notify_error)
                image.layoutParams = FrameLayout.LayoutParams(width, height)
    
                val frameLayout = FrameLayout(mView.context)
                frameLayout.setBackgroundColor(
                    ContextCompat.getColor(
                        mView.context,
                        android.R.color.holo_green_light
                    )
                )
                frameLayout.addView(image)
    
                frameLayout.measure(width, height)
                frameLayout.layout(0, 0, width, height)
                frameLayout.draw(canvas)
            }
        }
    }

图像随着手指拖放滑动：

![5461a4daea8a41bbbee7cbd43fa955a9.png][]

[Android View拖拽/拖放DragAndDrop自定义View.DragShadowBuilder，Kotlin（2）-CSDN博客文章浏览阅读54次。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。Android View拖拽startDragAndDrop，Kotlin-CSDN博客。![favicon32.ico][]https://blog.csdn.net/zhangphil/article/details/134008458][Android View_DragAndDrop_View.DragShadowBuilder_Kotlin_2_-CSDN_54_Android DynamicGrid_Android DynamicGrid_DynamicGrid_github_https_github.com_askerov_DynamicGrid_view_android _Android View_startDragAndDrop_Kotlin-CSDN_favicon32.ico_https_blog.csdn.net_zhangphil_article_details_134008458]

[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。![favicon32.ico][]https://blog.csdn.net/zhangphil/article/details/133994955][Android View_startDragAndDrop_Kotlin-CSDN_Android_Android DynamicGrid_Android DynamicGrid_DynamicGrid_github_https_github.com_askerov_DynamicGrid_view_android _favicon32.ico_https_blog.csdn.net_zhangphil_article_details_133994955]

[5461a4daea8a41bbbee7cbd43fa955a9.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/21/dca7955301854b9bbb24529095568808.png
[favicon32.ico]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/21/79327dd8e6de49f29eef63c3192a420d.png
[Android View_DragAndDrop_View.DragShadowBuilder_Kotlin_2_-CSDN_54_Android DynamicGrid_Android DynamicGrid_DynamicGrid_github_https_github.com_askerov_DynamicGrid_view_android _Android View_startDragAndDrop_Kotlin-CSDN_favicon32.ico_https_blog.csdn.net_zhangphil_article_details_134008458]: https://blog.csdn.net/zhangphil/article/details/134008458
[Android View_startDragAndDrop_Kotlin-CSDN_Android_Android DynamicGrid_Android DynamicGrid_DynamicGrid_github_https_github.com_askerov_DynamicGrid_view_android _favicon32.ico_https_blog.csdn.net_zhangphil_article_details_133994955]: https://blog.csdn.net/zhangphil/article/details/133994955