首先将您的EditText转换为MultiAutoCompleteTextView。MultiAutoCompleteTextView允许您替换文本中的某些部分,例如“@”后面的文本。
然后您可以像这样操作:
final MultiAutoCompleteTextView inputEditText = (MultiAutoCompleteTextView) dialog.findViewById(R.id.MyEditText);
String[] COUNTRIES = new String[] { "Belgium", "France", "Italy", "Germany", "Spain" };
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line, COUNTRIES);
inputEditText.setAdapter(adapter);
inputEditText.setThreshold(1);
inputEditText.setTokenizer(new Tokenizer() {
@Override
public CharSequence terminateToken(CharSequence text) {
int i = text.length();
while (i > 0 && text.charAt(i - 1) == ' ') {
i--;
}
if (i > 0 && text.charAt(i - 1) == ' ') {
return text;
} else {
if (text instanceof Spanned) {
SpannableString sp = new SpannableString(text + " ");
TextUtils.copySpansFrom((Spanned) text, 0, text.length(), Object.class, sp, 0);
return sp;
} else {
return text + " ";
}
}
}
@Override
public int findTokenStart(CharSequence text, int cursor) {
int i = cursor;
while (i > 0 && text.charAt(i - 1) != '@') {
i--;
}
if (i < 1 || text.charAt(i - 1) != '@') {
return cursor;
}
return i;
}
@Override
public int findTokenEnd(CharSequence text, int cursor) {
int i = cursor;
int len = text.length();
while (i < len) {
if (text.charAt(i) == ' ') {
return i;
} else {
i++;
}
}
return len;
}
});
这种方式的一个“问题”是弹出窗口将出现在EditText视图下方。为了将其移动并放置在当前编写文本下方,您可以执行以下操作:
inputEditText.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
Layout layout = inputEditText.getLayout();
int pos = inputEditText.getSelectionStart();
int line = layout.getLineForOffset(pos);
int baseline = layout.getLineBaseline(line);
int bottom = inputEditText.getHeight();
inputEditText.setDropDownVerticalOffset(baseline - bottom);
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void afterTextChanged(Editable s) {
}
});
注意:目前还没有处理下拉菜单位置的问题,如果编辑文本中有超过编辑文本可以显示的行数,则需要注意。