使用kotline 实现
时间: 2023-07-11 16:12:01 浏览: 42
以下是使用 Kotlin 实现 `NumSpaceTextWatcher` 的代码:
```kotlin
class NumSpaceTextWatcher(private val maxChars: Int, private val maxSpaces: Int) : TextWatcher {
private var numChars = 0
private var numSpaces = 0
override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
// do nothing
}
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
// update number of characters and spaces
numChars = countChars(s)
numSpaces = countSpaces(s)
}
override fun afterTextChanged(s: Editable?) {
// check if limits are exceeded
if (numChars > maxChars) {
removeExcessChars(s, numChars - maxChars)
}
if (numSpaces > maxSpaces) {
removeExcessSpaces(s, numSpaces - maxSpaces)
}
}
private fun countChars(s: CharSequence?): Int {
return s?.toString()?.replace("\\s".toRegex(), "")?.length ?: 0
}
private fun countSpaces(s: CharSequence?): Int {
return s?.toString()?.replace("\\S".toRegex(), "")?.length ?: 0
}
private fun removeExcessChars(s: Editable?, numExcessChars: Int) {
val start = s?.length?.minus(numExcessChars) ?: return
val end = s.length
s.delete(start, end)
}
private fun removeExcessSpaces(s: Editable?, numExcessSpaces: Int) {
val numSpacesToRemove = min(numExcessSpaces, numSpaces)
val numCharsToRemove = numExcessSpaces - numSpacesToRemove
val start = s?.length?.minus(numSpaces)?.minus(numCharsToRemove) ?: return
val end = s.length - numSpacesToRemove
s.delete(start, end)
}
}
```
使用方法:
```kotlin
val editText = findViewById<EditText>(R.id.editText)
editText.addTextChangedListener(NumSpaceTextWatcher(10, 3)) // limit to 10 characters and 3 spaces
```