如何在Android的
EditText
上设置最大字数限制。我知道如何设置字符限制,但是我正在寻找字数限制。EditText
上设置最大字数限制。我知道如何设置字符限制,但是我正在寻找字数限制。您需要向您的EditText
添加一个TextChangedListener
,然后应用一个InputFilter
,请参考以下代码。
edDesc.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {}
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
int wordsLength = countWords(s.toString());// words.length;
// count == 0 means a new word is going to start
if (count == 0 && wordsLength >= MAX_WORDS) {
setCharLimit(edDesc, edDesc.getText().length());
} else {
removeFilter(edDesc);
}
tvWordCount.setText(String.valueOf(wordsLength) + "/" + MAX_WORDS);
}
@Override
public void afterTextChanged(Editable s) {}
});
private int countWords(String s) {
String trim = s.trim();
if (trim.isEmpty())
return 0;
return trim.split("\\s+").length; // separate string around spaces
}
private InputFilter filter;
private void setCharLimit(EditText et, int max) {
filter = new InputFilter.LengthFilter(max);
et.setFilters(new InputFilter[] { filter });
}
private void removeFilter(EditText et) {
if (filter != null) {
et.setFilters(new InputFilter[0]);
filter = null;
}
}
为了防止用户粘贴超过规定字数,您需要拦截粘贴事件。您可以拦截Android中的EditText
粘贴事件[了解更多]
我为EditText制作了扩展函数,它运行得非常完美。
fun EditText.addWordCounter(func: (wordCount: Int?) -> Unit) {
addTextChangedListener(object :TextWatcher{
override fun afterTextChanged(s: Editable?) {}
override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {}
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
val trim = s?.trim()
val wordCount = if (trim?.isEmpty()!!or(false)) 0 else trim.split("\\s+".toRegex()).dropLastWhile { it.isEmpty() }.toTypedArray().size
func(wordCount)
}
})}
etDesc.addWordCounter { wordCount ->
Log.d(TAG, "addWordCounter: $wordCount")
}
binding.etSectionDesc.doAfterTextChanged { val count = binding.etSectionDesc.content().wordCount()
绑定.etSectionDesc.在文本更改后执行{ val count = binding.etSectionDesc.content().wordCount() }
if (count >= ValidationConst.MAX_COURSE_DESC_LENGTH_SHOW) {
setCharLimit(binding.etSectionDesc, binding.etSectionDesc.content().length)
} else {
removeFilter(binding.etSectionDesc)
}
binding.tvDescTotalChar.apply {
text = count.toString()
if (count < ValidationConst.MAX_COURSE_DESC_LENGTH_SHOW) {
setTextColor(ContextCompat.getColor(context, R.color.black))
} else {
setTextColor(context.getAttrResource(R.attr.accentColor_Red))
}
}
}
你可以限制在EditText中输入的字数。
简单地说,只需添加以下内容:
android:maxLength="10"
完整代码:
<EditText
android:id="@+id/uname"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="textPersonName"
android:maxLength="10"/>
官方文档 在这里
编程愉快 :)