Question

我在recyclerView中的notifyDataSetChanged期间在View中遇到问题。我实现了pull torefresh逻辑。所以我刷新了我的RecyclerView并调用notifyDataSetChanged。我动态创建一个线性布局并将其添加到父视图中。动态线性布局具有图像。最初加载时它会正确显示。在拉动刷新期间，图像会加载但会立即消失。我无法理解问题会是什么？

BindViewHolder的一部分

if(tempAvailable == true && heartAvailable == true && lungAvailable == true) {
    for(i in 1..3) {
        if(i == 1) {
            val df = DecimalFormat("#.##");
            var childLinearLayout:LinearLayout? = createChildView(BitmapFactory.decodeResource(context.getResources(), R.drawable.temperature), df.format(coreBodyTemp).toString(), context.getString(R.string.temperatureStr))
            parentLinearLayout.addView(childLinearLayout)
            //childLinearLayout = null
        } else if(i == 2) {
            var childLinearLayout:LinearLayout? = createChildView(BitmapFactory.decodeResource(context.getResources(), R.drawable.heart), heartRate.toString(), context.getString(R.string.heartRate))
            parentLinearLayout.addView(childLinearLayout)
            //childLinearLayout = null
        } else if(i == 3) {
            var childLinearLayout:LinearLayout? = createChildView(BitmapFactory.decodeResource(context.getResources(), R.drawable.lung), "", "")
            parentLinearLayout.addView(childLinearLayout)
           // childLinearLayout = null
        }
    }
} else if (tempAvailable) {
    val df = DecimalFormat("#.##");
    var childLinearLayout:LinearLayout? = createChildView(BitmapFactory.decodeResource(context.getResources(), R.drawable.temperature), df.format(coreBodyTemp).toString()+" \u00B0F", context.getString(R.string.temperatureStr))
    parentLinearLayout.addView(childLinearLayout)
    //childLinearLayout = null
} else if (heartAvailable) {
    var childLinearLayout:LinearLayout? = createChildView(BitmapFactory.decodeResource(context.getResources(), R.drawable.heart), heartRate.toString()+" bpm", context.getString(R.string.heartRate))
    parentLinearLayout.addView(childLinearLayout)
   // childLinearLayout = null
} else if (lungAvailable) {
    var childLinearLayout:LinearLayout? = createChildView(BitmapFactory.decodeResource(context.getResources(), R.drawable.lung), "", "")
    parentLinearLayout.addView(childLinearLayout)
    //childLinearLayout = null
}

动态创建线性布局的方法

fun createChildView(icon: Bitmap,readingVal: String, readingTag: String) : LinearLayout {
    val lp = LinearLayout.LayoutParams(0, ViewGroup.LayoutParams.WRAP_CONTENT)
    lp.weight = 1f
    val parent: LinearLayout = LinearLayout(context)
    parent.setOrientation(LinearLayout.HORIZONTAL)
    parent.setLayoutParams(lp)

    val imageView = ImageView(context)
    val layoutParams = LinearLayout.LayoutParams(0, ViewGroup.LayoutParams.WRAP_CONTENT)
    layoutParams.weight = 0.4f
    layoutParams.height = 60
    layoutParams.width = 60
    layoutParams.leftMargin = 10
    layoutParams.rightMargin = 10
    layoutParams.topMargin = 10
    layoutParams.bottomMargin =10

    imageView.setLayoutParams(layoutParams)
    imageView.setImageBitmap(icon)
    parent.addView(imageView)


    val readingLayout = LinearLayout(context)
    readingLayout.setOrientation(LinearLayout.VERTICAL)
    val lp1 = LinearLayout.LayoutParams(0, ViewGroup.LayoutParams.WRAP_CONTENT)
    lp1.weight = 0.6f
    lp1.topMargin = 10
    readingLayout.setLayoutParams(lp)

    val displayValue = TextView(context)
    val layoutParams1 = LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 0)
    layoutParams1.weight = 0.7f
    layoutParams1.topMargin = 24
    layoutParams1.bottomMargin = 4
    displayValue.setLayoutParams(layoutParams1)
    displayValue.setText(readingVal)
    displayValue.setTextSize(12f)
    displayValue.setTextColor(Color.BLACK)
    readingLayout.addView(displayValue)

    val displayTag = TextView(context)
    layoutParams1.weight = 0.3f
    layoutParams1.topMargin = 0
    displayTag.setLayoutParams(layoutParams1)
    displayTag.setText(readingTag)
    displayTag.setTextSize(8f)
    displayTag.setTextColor(Color.BLACK)
    displayTag.setAlpha(0.6f)
    readingLayout.addView(displayTag)
    parent.addView(readingLayout)

    return parent
}

更新：

我通过在Recycler视图构造函数

中放置setHasStableIds（true）来解决此问题

Answer 1

来自Android documentation，

setHasStableIds

void setHasStableIds（boolean hasStableIds）

指示数据集中的每个项目是否都可以用a表示 Long类型的唯一标识符。

您必须为回收视图设置setHasStableIds(true)

RecyclerView notifyDataset更改了问题

1 个答案:

setHasStableIds