如何在Android中的DataBinding的ViewModel类中获取R.string [英] How to Get R.string in ViewModel Class of DataBinding in Android

问题描述

我当前正在将 databinding 用于我的android应用程序项目。我想在 R.string.txtOldPassWordError CustomTextView 中设置错误消息code>并从另一个名为 ViewModelClass 的类进行设置。

I am currently using databinding for my android application project. I want to set the error message on my CustomTextView from R.string.txtOldPassWordError and set it up from another class called ViewModelClass.

这是我的XML代码

<com.horseproject.widget.CustomEditText
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="center_vertical"
    android:layout_marginTop="@dimen/dp_20"
    android:drawablePadding="@dimen/dp_10"
    android:hint="@string/enter_old_password"
    android:inputType="textPassword"
    android:lines="1"
    android:text="@={ChangePasswordVM.userOldPassword}"
    android:textColorHint="@color/gray_text"
    app:drawableLeftCompat="@drawable/ic_password_lock"
    app:drawableTintCompat="@color/gray_app"
    app:error="@{ChangePasswordVM.userOldPasswordError}" />

这是ViewModelClass.java

public class ChangePasswordViewModel extends BaseObservable {

    public ObservableField<String> userOldPassword = new ObservableField<>("");

    public void userPasswordChange() {

        if ((TextUtils.isEmpty(userOldPassword.get()))) {
            userOldPasswordError.set("Please enter your old password");
            return;
        } else if (userOldPassword.get().length() <= 5) {
            userOldPasswordError.set("Password should contain minimum 6 characters");
            return;
        } else {
            userOldPasswordError.set(null);
        }
    }
}

strings.xml

and this is string from strings.xml

<string name="select">Please Enter Old Password</string>

因此，我想在我的viewModel类中访问此字符串并将其设置为错误消息，而不是直接将其硬编码为字符串。

So, I want to access this string in my viewModel class and set it as error message instead of hardcoded it directly as string.

那么我该如何实现呢？我正在使用Android Studio 3.0 Beta版。

So how can i achieve this? I am using Android Studio 3.0 Beta Version. Any help would be really appreciated.

推荐答案

创建 ResourceProvider 类

public class ResourceProvider {

    private Context mContext;

    public ResourceProvider(Context mContext) {
        this.mContext = mContext;
    }

    public String getString(int resId) {
        return mContext.getString(resId);
    }

    public String getString(int resId, String value) {
        return mContext.getString(resId, value);
    }
}

现在转到您的 ApplicationClass 并粘贴

public class YourAppName extends Application {
  // Resource Provider
    private ResourceProvider mResourceProvider;
    public ResourceProvider getResourceProvider() {
        if (mResourceProvider == null)
            mResourceProvider = new ResourceProvider(this);

        return mResourceProvider;
    }
}

现在转到您的 ChangePasswordViewModel 并创建ResourceProvider的对象

now go to your ChangePasswordViewModel and create object of ResourceProvider

private ResourceProvider mResourceProvider;

并将其传递给 constroctor 的 ChangePasswordViewModel

您可以通过以下方式访问它

than you can access it by

 userOldPasswordError.set(mResourceProvider.getString(R.string.select));

这篇关于如何在Android中的DataBinding的ViewModel类中获取R.string的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！