Question

我正在尝试在编辑文本的textchanged事件上设置微调器的项目。但是我可以在textchanged事件上举杯，但不能设置微调框的选择

我想制作一个让客户可以从微调器列表中选择项目的应用程序客户也可以搜索该项目，并通过在编辑文本中输入该项目的特定部分，将其设置在微调器中。

Members_Spinner=findViewById(R.id.spinner_Members);
List<String> Members = hlpr.getParty();
membersArrayAdapter=new ArrayAdapter<String>(
        this,R.layout.spinner_layout_left,Members
);

membersArrayAdapter.setDropDownViewResource((R.layout.spinner_layout_left));
Members_Spinner.setAdapter((membersArrayAdapter));

etmemCode=findViewById(R.id.etMemCode);
etmemCode.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 a = s.toString();
        // This is  working ----
//Toast.makeText(activity_milk_purchase.this, a, Toast.LENGTH_SHORT).show();
        loadMember(a);----- this is not working...
    }

    @Override
    public void afterTextChanged(Editable s) {


    }
});

public void loadMember(String idTxt){
    int b=idTxt.length();
     if (b > 0) {
         for (int position = 0; position < membersArrayAdapter.getCount(); position++) {
            String c = membersArrayAdapter.getItem(position).toString();
            String d = c.substring(0, b);
            if (d == idTxt) {
                Members_Spinner.setSelection(position);
            }
        }
    }
}

XML

<EditText
    android:id="@+id/etMemCode"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_below="@+id/spinner_Session"
    android:hint="CODE"
    android:textSize="24dp"
    android:textAlignment="center"
    android:layout_margin="25dp"
    android:inputType="number"/>

<Spinner
    android:id="@+id/spinner_Members"
    android:layout_below="@id/etMemCode"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginLeft="25dp"
    android:layout_marginRight="25dp"
    android:padding="10dp"/>

Log Cat - Error:
2019-02-19 16:04:29.949 13005-13005/com.ksheera.lsstech.ksheerasagara 
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.ksheera.lsstech.ksheerasagara, PID: 13005
java.lang.StringIndexOutOfBoundsException: length=0; regionStart=0; regionLength=1
    at java.lang.String.substring(String.java:1931)
    at com.ksheera.lsstech.ksheerasagara.activity_milk_purchase.loadMember(activity_milk_purchase.java:69)
    at com.ksheera.lsstech.ksheerasagara.activity_milk_purchase$2.onTextChanged(activity_milk_purchase.java:87)
    at android.widget.TextView.sendOnTextChanged(TextView.java:8560)
    at android.widget.TextView.handleTextChanged(TextView.java:8625)
    at android.widget.TextView$ChangeWatcher.onTextChanged(TextView.java:10784)
    at android.text.SpannableStringBuilder.sendTextChanged(SpannableStringBuilder.java:1226)
    at android.text.SpannableStringBuilder.replace(SpannableStringBuilder.java:591)
    at android.text.SpannableStringBuilder.replace(SpannableStringBuilder.java:520)
    at android.text.SpannableStringBuilder.replace(SpannableStringBuilder.java:519)
    at android.text.method.NumberKeyListener.onKeyDown(NumberKeyListener.java:121)
    at android.widget.TextView.doKeyDown(TextView.java:6429)
    at android.widget.TextView.onKeyDown(TextView.java:6219)
    at android.view.KeyEvent.dispatch(KeyEvent.java:2754)
    at android.view.View.dispatchKeyEvent(View.java:9972)
    at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1697)
    at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1697)
    at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1697)
    at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1697)
    at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1697)
    at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1697)
    at com.android.internal.policy.DecorView.superDispatchKeyEvent(DecorView.java:427)
    at com.android.internal.policy.PhoneWindow.superDispatchKeyEvent(PhoneWindow.java:1822)
    at android.support.v4.view.KeyEventDispatcher.activitySuperDispatchKeyEventPre28(KeyEventDispatcher.java:130)
    at android.support.v4.view.KeyEventDispatcher.dispatchKeyEvent(KeyEventDispatcher.java:87)
    at android.support.v4.app.SupportActivity.dispatchKeyEvent(ComponentActivity.java:126)
    at android.support.v7.app.AppCompatActivity.dispatchKeyEvent(AppCompatActivity.java:535)
    at android.support.v7.view.WindowCallbackWrapper.dispatchKeyEvent(WindowCallbackWrapper.java:59)
    at android.support.v7.app.AppCompatDelegateImpl$AppCompatWindowCallback.dispatchKeyEvent(AppCompatDelegateImpl.java:2533)
    at com.android.internal.policy.DecorView.dispatchKeyEvent(DecorView.java:334)
    at android.view.ViewRootImpl$ViewPostImeInputStage.processKeyEvent(ViewRootImpl.java:4812)
    at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4777)
    at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4288)
    at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4341)
    at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4307)
    at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4454)
    at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4315)
    at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4511)
    at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4288)
    at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4341)
    at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4307)
    at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4315)
    at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4288)
    at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:6812)
    at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:6786)
    at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:6729)
    at android.view.ViewRootImpl$ViewRootHandler.handleMessage(ViewRootImpl.java:4074)
    at android.os.Handler.dispatchMessage(Handler.java:110)
    at android.os.Looper.loop(Looper.java:208)
    at android.app.ActivityThread.main(ActivityThread.java:6267)
2019-02-19 16:04:29.950 13005-13005/com.ksheera.lsstech.ksheerasagara E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1063)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:924)

Answer 1

我以为@ManishPrajapati是正确的建议.equals（）而不是==。但是您说您尝试了所有操作，但没有成功。因此，我像您一样制作了整个场景，使用.equals（）可以正常工作。并且在这里无法使用==。这是我的完整代码。

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
android:layout_margin="16dp"
android:gravity="center"
android:orientation="vertical"
tools:context=".MainActivity">

<EditText
    android:id="@+id/edittext_planet"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center"
    android:hint="Type text for spinner" />

<Spinner
    android:id="@+id/spinner_planet"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" />
</LinearLayout>

MainActivity.java

public class MainActivity extends AppCompatActivity {

private EditText planetEdittext;
private Spinner planetSpinner;
private List<String> planetList = new ArrayList<>();
ArrayAdapter<String> adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    planetEdittext=findViewById(R.id.edittext_planet);
    planetSpinner=findViewById(R.id.spinner_planet);

    planetEdittext.addTextChangedListener(textWatcher);

    planetList.add("Mercury");
    planetList.add("Venus");
    planetList.add("Earth");
    planetList.add("Mars");
    planetList.add("Jupiter");
    planetList.add("Saturn");

    adapter =new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, planetList) ;
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    planetSpinner.setAdapter(adapter);
}

public void loadSpinnerData(String planetName)
{
    for(int position=0;position<adapter.getCount();++position)
    {
        if(planetName.equals(adapter.getItem(position).toString()))
        {
            planetSpinner.setSelection(position);
        }
    }
}

TextWatcher textWatcher = 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) {
        loadSpinnerData(s.toString());
    }

    @Override
    public void afterTextChanged(Editable s) {
    }
};
}

请确保您输入的编辑文本与列表（金星/水星）中的行星名称完全相同，因为我不会区分大小写。

在编辑文本的文本更改事件上设置微调框的选定项目

1 个答案: