我正在开发一个将值从kW转换为km的应用程序，当我在EditText1中输入值而不使用任何按钮在视图中自动执行此操作时，我希望看到EditText2中的分数，但我没有想法如何做到这一点。现在我必须从Spinner中选择正确的值才能在EditText2中获得结果。这怎么改变？也许是以错误的方式我正在寻找Spinner的搜索值？我还会问你如何改进应用程序。谢谢。
我尝试使用TextWeatcher，但它仍无效。
MainActivity.java
public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
Spinner spinner1, spinner2;
EditText editText1, editText2;
double count = 1.36;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
spinner1 = (Spinner) findViewById(R.id.spinner1);
spinner2 = (Spinner) findViewById(R.id.spinner2);
editText1 = (EditText) findViewById(R.id.editText1);
editText2 = (EditText) findViewById(R.id.editText2);
editText1.addTextChangedListener(new TextWatcher() {
@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) {
String c = s.toString();
editText2.setText(c);
}
});
ArrayAdapter<CharSequence> adapter1 = ArrayAdapter.createFromResource(this, R.array.przelicznik_arrayKM,
android.R.layout.simple_spinner_item);
adapter1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner1.setAdapter(adapter1);
spinner1.setOnItemSelectedListener(this);
ArrayAdapter<CharSequence> adapter2 = ArrayAdapter.createFromResource(this, R.array.przelicznik_arraykW,
android.R.layout.simple_spinner_item);
adapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner2.setAdapter(adapter2);
spinner2.setOnItemSelectedListener(this);
}
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
Spinner spinner = (Spinner) parent;
String text = spinner1.getSelectedItem().toString();
String text2 = spinner2.getSelectedItem().toString();
if(text.equals("kW") & text2.equals("KM") ) {
try {
double a = Double.parseDouble(editText1.getText().toString());
double suma = a / count;
editText2.setText(String.valueOf(suma));
}catch (NumberFormatException e){
Toast.makeText(this, "Enter yout value!", Toast.LENGTH_SHORT).show();
}
}
if(text.equals("KM") & text2.equals("kW")){
try {
double a = Double.parseDouble(editText1.getText().toString());
double suma = a /count;
editText2.setText(String.valueOf(suma));
}catch (NumberFormatException e){
Toast.makeText(this, "Enter your value!", Toast.LENGTH_SHORT).show();
}
} else {
String textString = editText1.getText().toString();
editText2.setText(String.valueOf(textString));
}
}
@Override
public void onNothingSelected(AdapterView<?> parent) {}
public void clearEditText(View view) {
editText1.setText("");
editText2.setText("");
}
}
Strings.xml
<resources>
<string name="app_name">PrzelicznikMocySilnika</string>
<string-array name="przelicznik_arraykW">
<item>kW</item>
<item>KM</item>
</string-array>
<string-array name="przelicznik_arrayKM">
<item>KM</item>
<item>kW</item>
</string-array>
</resources>
Layout.xmln
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.hfad.przelicznikmocysilnika.MainActivity">
<EditText
android:id="@+id/editText1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:inputType="number"
android:hint="Enter your value"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_toLeftOf="@+id/spinner1"
android:layout_toStartOf="@+id/spinner1" />
<EditText
android:id="@+id/editText2"
android:hint="Enter your value"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_below="@+id/editText1"
android:ems="10"
android:inputType="number"
android:layout_toLeftOf="@+id/spinner2"
android:layout_toStartOf="@+id/spinner2" />
<Spinner
android:id="@+id/spinner1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_above="@+id/editText2" />
<Spinner
android:id="@+id/spinner2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="@+id/button"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_below="@+id/editText1" />
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/editText2"
android:layout_centerHorizontal="true"
android:layout_marginTop="25dp"
android:text="Reset"
android:textAllCaps="false"
android:onClick="clearEditText"/>
</RelativeLayout>
答案 0 :(得分：1)
使用onTextChanged方法
要获取当前值，请使用editText1.getText().toString()
答案 1 :(得分：0)
在onTextChanged而不是afterTextChanged
中添加你的逻辑editText1.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after){
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
String c = editText1.getText().toString();
editText2.setText(c);
}
@Override
public void afterTextChanged(Editable s) {
}
}
答案 2 :(得分：0)
对于两个EditText视图之间的双向转换，只有在edittext处于焦点时才需要进行转换。示例代码如下。
editText1.addTextChangedListener(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) {
if (editText1.isFocused()) {
String str = editText1.getText().toString().trim();
if (!str.isEmpty()) {
//your conversion logic here
editText2.setText(String.valueOf(convertedValue));
}else{
etTo.setText("0");
}
}
}
});
尝试使用类似的方法从editText2转换为editText1。
答案 3 :(得分：-1)
使用侦听器进行文本更改。
your_edittext.addTextChangedListener(new InputValidator());
private class InputValidator implements TextWatcher {
public void afterTextChanged(Editable s) {
}
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
}
public void onTextChanged(CharSequence s, int start, int before,
int count) {
}
}
}