使用DataBinding单击按钮后如何显示和隐藏视图

Question

我有2个Editfields，一个提交按钮和一个Textview，首先用户填写了编辑字段，然后单击提交按钮。我必须检查所有字段是否有效，如果有效，那么我想显示使用数据绑定显示textview。我在xml中遇到了数据绑定问题。我想我错过了什么这是我的textview

<data>

    variable
        name="helper"
        type="com.abc.online.views.helper.OtpNoteBinderHelper" />
</data>
<TextView
                    android:id="@+id/idtverrorMsg"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="@dimen/_3sdp"
                    android:fontFamily="@font/montserrat_regular"
                    android:gravity="center_horizontal"
                    android:letterSpacing="-0.01"
                    android:text="@string/ops_looks_like_you_apos_ve_entered_a_wrong_code"
                    android:textColor="#ff3b30"
                    android:textSize="@dimen/text_size_9"
                    app:presentation_note="false"
                    android:visibility="@{helper.is_presentation_note_visible ? View.VISIBLE : View.GONE}" />

这是我的助手课程

public class OtpNoteBinderHelper extends BaseObservable {
    private Boolean presentation_note;
    private Boolean timerElementsVisible;

    public OtpNoteBinderHelper(){
        this.presentation_note = true;
        this.timerElementsVisible = false;
    }
    public void setPresentationNoteViewVisible(boolean presentationElementsVisible) {
        this.presentation_note = presentationElementsVisible;

    }

    @Bindable
    public Boolean getPresentation_note() {
        return presentation_note;
    }

}

Answer 1

这可能不是你会发现的最好的答案，但它确实完成了工作..

由于我们没有使用双向数据绑定，我在MainActivity中听取了提交按钮的onClick，我在其中更改了NoteBinderhelper变量

    @Override
   protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    mainBinding = DataBindingUtil.setContentView(this, R.layout.activity_main);

    final NoteBinderhelper noteBinderhelper = new NoteBinderhelper();

    mainBinding.setHelper(noteBinderhelper);

    mainBinding.button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            String textOne = mainBinding.editText1.getText().toString();
            String textTwo = mainBinding.editText2.getText().toString();

            if(textOne.isEmpty() || textTwo.isEmpty()){
                noteBinderhelper.setPresentationNoteViewVisible(false);

            } else {
                noteBinderhelper.setPresentationNoteViewVisible(true);
            }
            mainBinding.setHelper(noteBinderhelper);
        }
    });

}

在NoteBinderHelper类中稍作修改

public class NoteBinderhelper extends BaseObservable {
private Boolean presentation_note;
private Boolean timerElementsVisible;

public NoteBinderhelper(){
    this.presentation_note = true;
    this.timerElementsVisible = false;
}
public void setPresentationNoteViewVisible(boolean presentationElementsVisible) {
    this.presentation_note = presentationElementsVisible;
    notifyPropertyChanged(BR.presentation_note);


 }

 @Bindable
 public Boolean getPresentation_note() {
    return presentation_note;
  } 
 }

我将textView的可见性更改为此

 android:visibility="@{helper.presentation_note ? View.VISIBLE : View.GONE}"

Answer 2

你应该在你的MainActivity中做，因为隐藏或显示textView是updateUI，所以你不要在OtpNoteBinderHelper类中做