目前，我使用RecyclerView来表示动态配置列表表单。
每个配置项（RecyclerView列表中的条目）都包含一个EditText项。 为了避免错误的用户输入（某些字段只允许整数，其他字段只允许一个逗号后的数字），我实现了两个不同的TextWatcher过滤器来纠正非法输入（＆＃34; DecimalFilterDigitsAfterComma＆＃34;＆＃34; DecimalFilterInteger＆ ＃34）。 我的RecyclerView共有16个配置项，但一次最多只能显示8个。
我的问题是TextWatchers被分配给特定的项目（整数和小数点TextEdit）。但是当我滚动一点时，它们会改变它们的顺序，以便交换十进制和整数滤波器。
TextWatcher项目将在ConfigurationAdapter内创建，它是RecyclerView.Adapter。我管理的事件是，只使用 mListConfigInit （项目的布尔标志列表）为每个条目创建一次TextWatcher。
ConfigurationAdapter.java：
public class ConfigurationAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
/*
...
*/
private List<ConfigItem> mConfiguration = new ArrayList<>();
// make sure that DecimalFilter is only created once for each item
private List<Boolean> mListConfigInit = new ArrayList<>();
public ConfigurationAdapter() {
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(
R.layout.listitem_configuration,
parent,
false);
final ConfigurationViewHolder vh = new ConfigurationViewHolder(v);
/*
...
*/
return vh;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
final ConfigurationViewHolder vh = (ConfigurationViewHolder) holder;
ConfigItem config = mConfiguration.get(position);
if(config.ShowValueAsFloat()) {
vh.SetTextWatcherType(ConfigurationViewHolder.TextWatcherType.type_FloatActive);
} else {
vh.SetTextWatcherType(ConfigurationViewHolder.TextWatcherType.type_IntActive);
}
// set name and unit
vh.mName.setText(config.mName);
vh.mUnit.setText(config.mUnit);
/*
...
*/
}
@Override
public int getItemCount() {
return mConfiguration.size();
}
public void addConfigItem(ConfigItem item) {
mConfiguration.add(item);
mListConfigInit.add(new Boolean(false));
notifyItemInserted(mConfiguration.size() - 1);
//notifyDataSetChanged();
}
/*
...
*/
}
ConfigurationViewHolder.java（根据pskink-comments更改）：
public final class ConfigurationViewHolder extends RecyclerView.ViewHolder implements TextWatcher {
public TextView mName;
public CheckBox mCheckbox;
public SeekBar mSeekbar;
public EditText mValueEditText;
public TextView mUnit;
private List<TextWatcher> mListTextWatchers = new ArrayList<>();
public enum TextWatcherType {
type_FloatActive(0),
type_IntActive(1);
private int mValue;
TextWatcherType(int value) {
mValue = value;
}
int val() { return mValue; }
}
private TextWatcherType mTextWatcherType = TextWatcherType.type_FloatActive;
public ConfigurationViewHolder(View itemView) {
super(itemView);
mName = (TextView) itemView.findViewById(R.id.textView_configuration_name);
mValueEditText = (EditText) itemView.findViewById(R.id.editText_configuration_value);
mUnit = (TextView) itemView.findViewById(R.id.textView_configuration_unit);
mCheckbox = (CheckBox) itemView.findViewById(R.id.checkbox_configuration);
mSeekbar = (SeekBar) itemView.findViewById(R.id.seekBar_configuration);
mListTextWatchers.add(0, new DecimalFilterDigitsAfterComma(mValueEditText, 1));
mListTextWatchers.add(1, new DecimalFilterInteger(mValueEditText));
mValueEditText.addTextChangedListener(this);
}
public void SetTextWatcherType(TextWatcherType textWatcherType) {
mTextWatcherType = textWatcherType;
}
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {}
@Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {}
@Override
public void afterTextChanged(Editable editable) {
mListTextWatchers.get(mTextWatcherType.val()).afterTextChanged(editable);
}
}
DecimalFilterInteger.java
public class DecimalFilterInteger implements TextWatcher {
private final static String TAG = ConfigurationAdapter.class.getSimpleName();
private final EditText mEditText;
private String mLastTextValue = new String("");
public DecimalFilterInteger(EditText editText) {
this.mEditText = editText;
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
@Override
public synchronized void afterTextChanged(final Editable text) {
String strInput = text.toString().trim();
if(strInput.isEmpty()) {
return;
}
if(strInput.equals(mLastTextValue)) { // return when same value as last time to avoid endless loop
return;
}
if ((strInput.charAt(0) == '.')) { // handle dot at beginning
strInput = "";
}
if(strInput.contains(".")){ // cut trailing comma
String numberBeforeDecimal = strInput.split("\\.")[0];
strInput = numberBeforeDecimal;
}
mEditText.removeTextChangedListener(this);
mEditText.getText().clear(); // do not use setText here to avoid changing the keyboard
mEditText.append(strInput); // back to default (e. g. from 123-mode to abc-mode),
// see: http://stackoverflow.com/questions/26365808/edittext-settext-changes-the-keyboard-type-to-default-from-123-to-abc
mLastTextValue = mEditText.getText().toString();
mEditText.setSelection(mEditText.getText().toString().trim().length());
mEditText.addTextChangedListener(this);
}
}
非常感谢您的帮助！
答案 0 :(得分：0)
RecyclerView中两个不同TextWatcher实现的交换/切换行为的原因是我在removeTextChangedListener - 方法中调用addTextChangedListener和afterTextChanged以避免重新触发afterTextChanged - 方法。
避免重新触发的最佳方法是简单检查自上次调用后文本是否发生了变化：
public class DecimalFilterInteger implements TextWatcher {
private final static String TAG = ConfigurationAdapter.class.getSimpleName();
private final EditText mEditText;
private String mLastTextValue = new String("");
// ...
@Override
public synchronized void afterTextChanged(final Editable text) {
String strInput = text.toString().trim();
if(strInput.isEmpty()) {
return;
}
if(strInput.equals(mLastTextValue)) { // return when same value as last time to avoid endless loop
return;
}
if ((strInput.charAt(0) == '.')) { // handle dot at beginning
strInput = "";
}
if(strInput.contains(".")){ // cut trailing comma
String numberBeforeDecimal = strInput.split("\\.")[0];
strInput = numberBeforeDecimal;
}
//mEditText.removeTextChangedListener(this); // CAUSE OF SWAP-ERROR !!!
mEditText.getText().clear(); // do not use setText here to avoid changing the keyboard
mEditText.append(strInput); // back to default (e. g. from 123-mode to abc-mode),
// see: http://stackoverflow.com/questions/26365808/edittext-settext-changes-the-keyboard-type-to-default-from-123-to-abc
mLastTextValue = mEditText.getText().toString();
mEditText.setSelection(mEditText.getText().toString().trim().length());
//mEditText.addTextChangedListener(this); // CAUSE OF SWAP-ERROR !!!
}
}