我的应用程序上有一个新闻部分,该部分从我的网站加载一些新闻,其中一些包含图片,因此我从互联网上加载它们。但是,当未加载图片时,会有一个绿色方块,只有在加载图片时才会消失。
未加载图片:
然后加载图片:
我想使绿色正方形不可见。
为简单起见,我们假设我什至不加载图像,只是想使绿色正方形不可见,而不用空文本替换图像标签。
代码:
val exampleText = "Example <br> <img src=\"https://www.w3schools.com/images/w3schools_green.jpg\" alt=\"W3Schools.com\"> <br> Example"
tv_body.text = fromHtml(exampleText)
fun fromHtml(html: String?): Spanned? {
return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
Html.fromHtml(html,Html.FROM_HTML_MODE_LEGACY);
} else {
Html.fromHtml(html);
}
}
有没有一种方法可以更改默认图像而不进行任何欺骗?
我的解决方法:
我要做的就是改编自定义的fromHtml函数。
private var drawable: Drawable? = null
fun fromHtml(context: activity?,tv: TextView?,text: String?) {
if (TextUtils.isEmpty(text) || context == null || tv == null) return
//Replace all image tags with an empty text
val noImageText = text!!.replace("<img.*?>".toRegex(),"")
//Set the textview text with the imageless html
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
tv.text = Html.fromHtml(noImageText,Html.FROM_HTML_MODE_LEGACY)
} else {
tv.text = Html.fromHtml(noImageText)
}
Thread {
//Creating the imageGetter
val imageGetter = ImageGetter { url ->
drawable = getImageFromNetwork(url)
if (drawable != null) {
var w = drawable!!.intrinsicWidth
var h = drawable!!.intrinsicHeight
// Scaling the width and height
if (w < h && h > 0) {
val scale = 400.0f / h
w = (scale * w).toInt()
h = (scale * h).toInt()
} else if (w > h && w > 0) {
val scale = 1000.0f / w
w = (scale * w).toInt()
h = (scale * h).toInt()
}
drawable!!.setbounds(0,w,h)
} else if (drawable == null) {
return@ImageGetter null
}
drawable!!
}
val textWithImage = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
Html.fromHtml(text,Html.FROM_HTML_MODE_LEGACY,imageGetter,null)
} else {
Html.fromHtml(text,null)
}
// update runOnUiThread and change the textview text from the textWithoutImage to the textWithImage
context.runOnUiThread(Runnable { tv.text = textWithImage })
}.start()
}
private fun getImageFromNetwork(imageUrl: String): Drawable? {
var myFileUrl: URL? = null
var drawable: Drawable? = null
try {
myFileUrl = URL(imageUrl)
val conn = myFileUrl
.openConnection() as HttpURLConnection
conn.doInput = true
conn.connect()
val `is` = conn.inputStream
drawable = Drawable.createFromStream(`is`,null)
`is`.close()
} catch (e: Exception) {
e.printStackTrace()
return null
}
return drawable
}
所以当我打电话给这个
val exampleText = "Example <br> <img src=\"https://www.w3schools.com/images/w3schools_green.jpg\" alt=\"W3Schools.com\"> <br> Example"
fromHtml((activity as Newsactivity?),tv_body,exampleText)
它首先显示了这一点:
(因为我用空文本替换了图片标签)
然后在图像加载时显示以下内容:
我仍然认为制作无图像的文字不是解决方案,而是适当的解决方案,我认为可能更简单一些:
<style name="LIGHT" parent="Theme.AppCompat.DayNight.DarkactionBar">
<item name="android:placeHolderDefaultImage">@drawable/invisible</item>
因此,绿色方块将是一个不可见的可绘制对象,尽管我真的不知道如何更改该默认占位符图像,但我不需要设置两次html文本。猜猜我会坚持解决方法