适用于Android的MVVM活动意图

Question

I am trying out MVVM for Android. I have a button which opens up another activity onClick. Codes below:

View:

    <LinearLayout
            android:id="@+id/activity_test"
            android:orientation="vertical"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            tools:context=".mvvm.view.TestActivity">

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Activity"
            android:onClick="@{viewModel.onClickButton1}"/>

    </LinearLayout>

ViewModel:

public View.OnClickListener onClickButton1() {
    return view -> {
        mContext.startActivity(new Intent(mContext, MockActivity.class));
    };
}

This doesn't seem to work for me. When I click on the button, MockActivity doesn't get started. What could be the problem?

Answer 1

in your view file did u bind your view to your viewmodel?

binding.setViewModel(viewModel);

Answer 2

As a suggestion, it is better to not include view event listeners in your ViewModel but instead putting them inside the View (activity or fragment here), Then you can call the view model methods to do the work. The idea is, ViewModel should not have any reference to view classes at all but in your code your passing a view to the onClickButton1 method.

Answer 3

尝试使用viewModel :: onClickButton1而不是viewModel.onClickButton1

Answer 4

The code in your VM class should be

public void onMyButtonClicked(View view) {
    // YOUR CODE HERE
}

And in the xml:

<Button
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:onClick="@{offlineDownloadsVM::onMyButtonClicked}"/>