CODEWITHSUNDEEP
android-databindingandroid-mvvm
DevinM
DevinM

Reputation: 1312

Android Data Binding "cannot find method"

This is seemingly old at this point. I have been reviewing Android Data Binding Documentation

As well pouring over posts here on SO however nothing seems to work.

No matter how I format the XML I get the same results. When I originally got this working (using lambda without passing arguments) took me a lot of trial and error. Now that i need to pass View in an onClick, im back to trial and error yet nothing is functional.

MainViewModel.java

private void navClicked(@NonNull View view) {
    switch (view.getId()) {
        case R.id.btn1:
            break;
        case R.id.btn2:
            break;
    }
}

public void testBtn() {}

activity_main.xml

<data>
    <variable
        name="mainViewModel"
        type="com.example.viewmodel.MainViewModel" />
</data>

<!-- Works perfectly -->
<!-- however I would need a method for every button and that becomes redundant -->
<Button
    android:id="@+id/testBtn"
    android:onClick="@{() -> mainViewModel.testBtn()}"
    android:text="@string/testBtn" />

<!-- "msg":"cannot find method navClicked(android.view.View) in class com.example.viewmodel.MainViewModel" -->
<Button
    android:id="@+id/btn1"
    android:onClick="@{(v) -> mainViewModel.navClicked(v)}"
    android:text="@string/btn1" />

<!-- "msg":"cannot find method navClicked(android.view.View) in class com.example.viewmodel.MainViewModel" -->
<Button
    android:id="@+id/btn2"
    android:onClick="@{mainViewModel::navClicked}"
    android:text="@string/btn2" />

<!-- "msg":"Could not find identifier \u0027v\u0027\n\nCheck that the identifier is spelled correctly, and that no \u003cimport\u003e or \u003cvariable\u003e tags are missing." -->
<!-- This is missing (view) in the lambda - makes sense to fail -->
<Button
    android:id="@+id/btn3"
    android:onClick="@{() -> mainViewModel.navClicked(v)}"
    android:text="@string/btn2" />

Upvotes: 1

Views: 1953

Answers (2)

Sepehr
Sepehr

Reputation: 1

Once I tried this and it worked:

XML:

android:onClick="@{() -> model.clickEvent(123)}"

Model:

public void clickEvent(int id) {...}

I used string for id but I think it also works with integer.

Upvotes: 0

DevinM
DevinM

Reputation: 1312

navClicked() was private...

// **denotes change, will not compile like that**
**public** void navClicked(@NonNull View view) {
    switch (view.getId()) {
        case R.id.btn1:
            break;
        case R.id.btn2:
            break;
    }
}

Upvotes: 1

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