我有一个视图,我想在点击时更改其大小.

我有以下测试布局：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <pro.labster.coloringbook.ui.view.ColorView
        android:id="@+id/colorView"
        android:layout_width="@dimen/colorSize"
        android:layout_height="@dimen/colorSize"
        android:layout_centerInParent="true"
        app:normalSize="@dimen/colorSize"
        app:selectedSize="@dimen/selectedColorSize" />

</RelativeLayout>

以下代码：

val colorView = findViewById<ColorView>(R.id.colorView)
colorView.setBackgroundColor(Color.RED)
colorView.setonClickListener {
    isSelected = !isSelected
    colorView.setColorSelected(isSelected)
}

尺码变更代码：

fun setColorSelected(isSelected: Boolean) {
        if (isColorSelected != isSelected) {
            if (isSelected) {
                setCurrentSize(selectedSize.toInt())
            } else {
                setCurrentSize(normalSize.toInt())
            }
        }

        isColorSelected = isSelected
    }

private fun setCurrentSize(size: Int) {
    if (layoutParams.height != size || layoutParams.width != size) {
        layoutParams.width = size
        layoutParams.height = size
        requestLayout()
    }
}

它运作良好：

https://www.youtube.com/watch?v=Ft8xcX5Qxbg

但是,如果我将此视图添加到RecyclerView,它会在大小更改上滞后：

class ColorsAdapter(colorsHex: List<String>) : RecyclerView.Adapter<ColorsAdapter.ViewHolder>() {

    private val colors = mutablelistof<Int>()
    private var selectedPosition: Int = 0

    init {
        colorsHex.forEach {
            colors.add(Color.parseColor(it))
        }
    }

    override fun getItemCount() = colors.size

    override fun onBindViewHolder(holder: ViewHolder,position: Int) {
        val color = colors[position]

        holder.colorView.setBackgroundColor(color)
        holder.colorView.tag = position

        holder.colorView.setColorSelected(position == selectedPosition)
    }

    override fun onCreateViewHolder(parent: ViewGroup?,viewType: Int): ViewHolder {
        val inflater = LayoutInflater.from(parent?.context)

        val view = inflater.inflate(R.layout.view_item_color,parent,false)

        return ViewHolder(view)
    }


    inner class ViewHolder(itemView: View?) : RecyclerView.ViewHolder(itemView) {
        val colorView: ColorView = itemView!!.findViewById(R.id.colorView)

        init {
            colorView.setonClickListener {
                val oldPosition = selectedPosition

                selectedPosition = colorView.tag as Int

                if (oldPosition != selectedPosition) {
                    notifyItemChanged(oldPosition)
                    notifyItemChanged(selectedPosition)
                }
            }
        }
    }

}

view_item_color.xml：

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="@dimen/selectedColorSize"
    android:layout_height="@dimen/selectedColorSize">

    <pro.labster.coloringbook.ui.view.ColorView
        android:id="@+id/colorView"
        android:layout_width="@dimen/colorSize"
        android:layout_height="@dimen/colorSize"
        android:layout_gravity="center"
        app:normalSize="@dimen/colorSize"
        app:selectedSize="@dimen/selectedColorSize" />

</FrameLayout>

https://www.youtube.com/watch?v=m8g6zpj9aDg

正如我所看到的,它也试图改变尺寸变化的动画 – 这是真的吗？

以及如何解决这个滞后？

如 docs of DefaultItemAnimator所示：

This implementation of RecyclerView.ItemAnimator provides basic animations on remove,add,and move events that happen to the items in a RecyclerView. RecyclerView uses a DefaultItemAnimator by default.

如果要删除这些动画,请忽略默认动画师：

recyclerview.itemAnimator = null

在我的程序中,关闭 java.util.RandomAccessFile有时需要45秒(几乎恰好在44.998和45.003秒之间).该程序创建和关闭大量小文件.通常关闭文件非常快(0到0.1秒之间).如果我调试该程序,它将被粘贴在本地方法RandomAccessFile.close0中.

当使用FileOutputStream而不是RandomAccessFile(在这种情况下,程序在本地方法FileOutputStream.close0中被阻止)时,也会出现同样的问题.

有人有想法可能是什么？你可以重现系统上的问题(我只能在Mac上重现,而不是在Windows XP上,我还没有在Linux上测试)？

更新2：

这仅仅是在Mac OS X上发生.我使用JDK 1.6.0_22-b04.它发生在32位和64位.在Windows XP上似乎并没有发生.

我的测试用例是：

import java.io.File;
import java.io.RandomAccessFile;
public class TestFileClose {
    public static void main(String... args) throws Exception {
        for (int i = 0; i < 100000; i++) {
            String name = "test" + i;
            RandomAccessFile r = new RandomAccessFile(name,"rw");
            r.write(0);
            long t = System.currentTimeMillis();
            r.close();
            long close = System.currentTimeMillis() - t;
            if (close > 200) {
                System.out.println("closing " + name +
                        " took " + close + " ms!");
            }
            if (i % 2000 == 0) {
                System.out.println("test " + i + "/100000");
            }
            new File(name).delete();
        }
    }
}

在我的机器上输出示例：

test 0/100000
test 2000/100000
test 4000/100000
test 6000/100000
test 8000/100000
test 10000/100000
closing test10030 took 44998 ms!
test 12000/100000
test 14000/100000
test 16000/100000
closing test16930 took 44998 ms!
test 18000/100000
test 20000/100000

这可能是我的机器上安装的McAfee防病毒软件.我不得不安装它…但是如果禁用按访问扫描,问题也会显示出来.

为了唯一的方法来验证它不是防病毒是有人在他的机器上重复测试(没有防病毒),并得到相同的问题,我猜.