java - android 点击后颜色没有变化是为什么？

Question

如题，android 点击后颜色没有变化是为什么？ 以下是具体代码

public class HomeFragmentVM extends ViewModel {    @SuppressLint("StaticFieldLeak")    private HomeFragment fragment;    public static final String SORT_COLUMN_AUTO = "auto";    public static final String SORT_COLUMN_ACTIVE = "active";    public static final String SORT_COLUMN_DISTANCE = "distance";    public static final String SORT_COLUMN_MATCH = "match";    public static final String SORT_ICON_DOWN = "sort:icon:down";    public static final String SORT_ICON_UP = "sort:icon:up";    public final MutableLiveData<SearchForm> searchForm = new MutableLiveData<>();    @SuppressLint("StaticFieldLeak")    public View rootView;    private static class SearchForm {        public String sortType = "asc";        public String sortColumn = SORT_COLUMN_ACTIVE;    }    public HomeFragmentVM(HomeFragment fragment, View rootView) {        this.fragment = fragment;        this.rootView = rootView;        this.init();    }    private void init() {        this.searchForm.setValue(new SearchForm());    }    public int getSortTextColor(String sortColumn) {        SearchForm searchForm = this.searchForm.getValue();        int color = R.color.color_333;        int colorActive = R.color.color_red_1;        if (searchForm == null) {            return color;        }        if (searchForm.sortColumn.equals(sortColumn)) {            return colorActive;        }        return color;    }    public void handleSort(String column) {        SearchForm searchForm = this.searchForm.getValue();        if (searchForm.sortColumn.equals(column) && column.equals(SORT_COLUMN_AUTO)) {            return ;        }        if (searchForm.sortColumn.equals(column)) {            // 重复点击搜索项 - 取消排序            searchForm.sortColumn = null;            searchForm.sortType = null;        } else {            searchForm.sortColumn = column;            if (column.equals(SORT_COLUMN_AUTO)) {                searchForm.sortType = null;            } else {                if (searchForm.sortType == null) {                    searchForm.sortType = "asc";                }                if (searchForm.sortType.equals("asc")) {                    searchForm.sortType = "desc";                }                if (searchForm.sortType.equals("desc")) {                    searchForm.sortType = null;                }            }        }        // 更新数据        this.searchForm.setValue(searchForm);    }

视图代码如下：

<?xml version="1.0" encoding="utf-8"?><layout    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">    <data>        <import type="com.gv.yinyuan.app.android.consts.AppConsts"/>        <variable name="vm" type="com.gv.yinyuan.app.android.vm.HomeFragmentVM"/>    </data>    <TextView        style="@style/fragment_home_sort_text"        android:text="综合"        android:textColor='@{vm.getSortTextColor(vm.SORT_COLUMN_AUTO)}'        android:layout_marginEnd="10dp"        android:onClick='@{(view) -> vm.handleSort(vm.SORT_COLUMN_AUTO)}'    /></layout>

Answer 1

layout 文件写错了
android:textColor="@={model.xxx}"
应该采用双向绑定的方式，然后这个model.xxx 应该是一个 Observable,
然后点击 TextView 后执行操作，过程中更新改变 model.xxx，这样就可以实现点击变化颜色

Answer 2

Data Binding 设置是这样吗

HomeFragmentBinding binding = DataBindingUtil.setContentView(this, R.layout.fragment_home);HomeFragmentVM viewModel = new HomeFragmentVM(fragment, rootView);binding.setVm(viewModel);

用 ObservableField：

public final ObservableField<SearchForm> searchForm = new ObservableField<>();// ...public void handleSort(String column) {    SearchForm searchForm = this.searchForm.get();    // 更新 searchForm    // ...    this.searchForm.set(searchForm); // 触发绑定更新}