我在视图布局中有三个 EditText
组件。有没有一种方法可以为这三个 EditText
使用一个单独的 TextWatcher
?
我在视图布局中有三个 EditText
组件。有没有一种方法可以为这三个 EditText
使用一个单独的 TextWatcher
?
我刚遇到了这个问题。我通过创建一个内部类实现TextWatcher
并将一个View作为参数传递来解决它。然后,在方法实现中,只需根据视图进行切换以查看Editable
来自哪个视图。
声明:
private class GenericTextWatcher implements TextWatcher{
private View view;
private GenericTextWatcher(View view) {
this.view = view;
}
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {}
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {}
public void afterTextChanged(Editable editable) {
String text = editable.toString();
switch(view.getId()){
case R.id.name:
model.setName(text);
break;
case R.id.email:
model.setEmail(text);
break;
case R.id.phone:
model.setPhone(text);
break;
}
}
}
用法:
name = (EditText) findViewById(R.id.name);
name.setText(model.getName());
name.addTextChangedListener(new GenericTextWatcher(name));
email = (EditText) findViewById(R.id.email);
email.setText(model.getEmail());
email.addTextChangedListener(new GenericTextWatcher(email));
phone = (EditText) findViewById(R.id.phone);
phone.setText(model.getPhone());
phone.addTextChangedListener(new GenericTextWatcher(phone));
如果你想要仅在文本变化后比较可编辑内容:
@Override
public void afterTextChanged(Editable editable) {
if (editable == mEditText1.getEditableText()) {
// DO STH
} else if (editable == mEditText2.getEditableText()) {
// DO STH
}
}
==
才能正确运行,使用 .equals()
会无效。 - Jarett Millardpublic class MultiTextWatcher {
private TextWatcherWithInstance callback;
public MultiTextWatcher setCallback(TextWatcherWithInstance callback) {
this.callback = callback;
return this;
}
public MultiTextWatcher registerEditText(final EditText editText) {
editText.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
callback.beforeTextChanged(editText, s, start, count, after);
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
callback.onTextChanged(editText, s, start, before, count);
}
@Override
public void afterTextChanged(Editable editable) {
callback.afterTextChanged(editText, editable);
}
});
return this;
}
interface TextWatcherWithInstance {
void beforeTextChanged(EditText editText, CharSequence s, int start, int count, int after);
void onTextChanged(EditText editText, CharSequence s, int start, int before, int count);
void afterTextChanged(EditText editText, Editable editable);
}
}
new MultiTextWatcher()
.registerEditText(editText1)
.registerEditText(editText2)
.registerEditText(editText3)
.setCallback(new TextWatcherWithInstance() {
@Override
public void beforeTextChanged(EditText editText, CharSequence s, int start, int count, int after) {
// TODO: Do some thing with editText
}
@Override
public void onTextChanged(EditText editText, CharSequence s, int start, int before, int count) {
// TODO: Do some thing with editText
}
@Override
public void afterTextChanged(EditText editText, Editable editable) {
// TODO: Do some thing with editText
}
});
这段代码将起作用
TextWatcher watcher = new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
//YOUR CODE
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
//YOUR CODE
}
@Override
public void afterTextChanged(Editable s) {
String outputedText = s.toString();
mOutputText.setText(outputedText);
}
};
然后在oncreate中添加这个内容
mInputText.addTextChangedListener(watcher);
e2.addTextChangedListener(watcher);
e3.addTextChangedListener(watcher);
e4.addTextChangedListener(watcher);
如果你想要使用onTextChanged,请参考下面提到的hashCode()
进行比较 -
@Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
if(charSequence.hashCode() == first_edit_text.getText().hashCode()){
// do other things
}
if(charSequence.hashCode() == second_edit_text.getText().hashCode()){
// do other things
}
}
或者
如果你想使用 afterTextChanged,请比较下面提到的 Editable
-
@Override
public void afterTextChanged(Editable editable) {
if (editable == first_edit_text.getEditableText()) {
// do other things
} else if (editable == second_edit_text.getEditableText()) {
// do other things
}
}
val mTextWatcher = object : TextWatcher {
override fun afterTextChanged(et: Editable?) {
when {
et === et1.editableText -> {
Toast.makeText(this@MainActivity, "EditText 1", Toast.LENGTH_LONG).show()
}
et === et2.editableText -> {
Toast.makeText(this@MainActivity, "EditText 2", Toast.LENGTH_LONG).show()
}
}
}
override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
}
override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
}
}
et1.addTextChangedListener(mTextWatcher)
et2.addTextChangedListener(mTextWatcher)
我知道这是一个旧问题,但有正确的决定。我将写下自己的解决方案,希望能帮到某些人。
模拟一个经典例子,我们有N个EditText,如果所有字段都填满,我们想要显示按钮。这个例子很有意义,尤其是如果进一步为每个字段使用验证器。
我根据这个问题制作了一个示例,但您可以进行任何设置
MultiEditText.class
public class MultiEditText extends AppCompatActivity{
EditText ed_1, ed_2, ed_3;
Button btn_ok;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.multi_edit_text);
ed_1 = (EditText) findViewById(R.id.ed_1);
ed_2 = (EditText) findViewById(R.id.ed_2);
ed_3 = (EditText) findViewById(R.id.ed_3);
btn_ok = (Button) findViewById(R.id.btn_ok);
btn_ok.setEnabled(false);
//if want more here can cycle interface List
EditText[] edList = {ed_1, ed_2, ed_3};
CustomTextWatcher textWatcher = new CustomTextWatcher(edList, btn_ok);
for (EditText editText : edList) editText.addTextChangedListener(textWatcher);
}
}
现在看起来非常简单。
自定义文本监听器类
public class CustomTextWatcher implements TextWatcher {
View v;
EditText[] edList;
public CustomTextWatcher(EditText[] edList, Button v) {
this.v = v;
this.edList = edList;
}
@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 void afterTextChanged(Editable s) {
for (EditText editText : edList) {
if (editText.getText().toString().trim().length() <= 0) {
v.setEnabled(false);
break;
}
else v.setEnabled(true);
}
}
}
我将添加一个布局,以便您不会浪费时间。
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="16dp">
<EditText
android:id="@+id/ed_1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="8dp" />
<EditText
android:id="@+id/ed_2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/ed_1"
android:layout_centerHorizontal="true"
android:layout_marginTop="8dp" />
<EditText
android:id="@+id/ed_3"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/ed_2"
android:layout_centerHorizontal="true"
android:layout_marginTop="8dp" />
<Button
android:id="@+id/btn_ok"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/ed_3"
android:layout_centerHorizontal="true"
android:layout_marginTop="8dp"
android:text="OK" />
</RelativeLayout>
让你的类继承自Activity并实现TextWatcher。
然后通过多态的魔力,你只需要订阅事件。
这不会告诉你TextEdit改变了什么,但是使用这个和Sky Kelsey的答案的组合,你可以很好地解决这个问题。
public YourActivity extends Activity implements TextWatcher {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_YourActivity);
//Subscribe to the events
EditText txt1 = (EditText) findViewById(R.id.txt1);
txt1.addTextChangedListener(this);
EditText txt2 = (EditText) findViewById(R.id.txt2);
txt2.addTextChangedListener(this);
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
EditText txt1 = (EditText) findViewById(R.id.txt1);
EditText txt2 = (EditText) findViewById(R.id.txt2);
// You probably only want the text value from the EditText. But you get the idea.
doStuff(txt1,txt2);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.calc, menu);
return true;
}
@Override
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
// TODO Auto-generated method stub
}
}
TextWatcher watcher = new TextWatcher(){
@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) {
}
};
然后:
editText1.addTextChangedListener(watcher);
editText2.addTextChangedListener(watcher);
editText3.addTextChangedListener(watcher);
public class MainActivity extends AppCompatActivity{
EditText value1, value2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//instantiate EditText controls
value1 = (EditText)findViewById(R.id.txtValue1);
value2 = (EditText)findViewById(R.id.txtValue2);
//set up text changed listener
value1.addTextChangedListener(new TextChange(value1));
value2.addTextChangedListener(new TextChange(value2));
//inner class
private class TextChange implements TextWatcher {
View view;
private TextChange (View v) {
view = v;
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
switch (view.getId()) {
case R.id.txtValue1:
//insert your TextChangedListener codes here
break;
case R.id.txtValue2:
//insert your TextChangedListener codes here
break;
}
}
}
}
}