如何使用EditTextPreference作为屏蔽密码文本字段？

Question

我有一个非常简单的问题:
我有一个EditTextPreference对话框,我想用它来获取用户的密码,我希望它被屏蔽.

我怎样才能做到这一点？

Answer 1

以下是使用xml的简短示例:

<EditTextPreference
    android:key="@string/key"
    android:title="@string/title"
    android:summary="@string/summary"   
    android:inputType="textPassword" />

或者你可以用numberPassword而不是textPassword.

Answer 2

对于androidx库，您应该以编程方式执行此操作，例如您可以按如下方式执行此操作，我可以选择根据密码的长度设置带有星号的摘要：

[...]
import android.os.Bundle;
import android.text.InputType;
import android.widget.EditText;

import androidx.annotation.NonNull;

import androidx.preference.EditTextPreference;
import androidx.preference.Preference;
import androidx.preference.PreferenceFragmentCompat;
import androidx.preference.PreferenceManager;

import static androidx.preference.EditTextPreference.*;

public class MySettingsFragment extends PreferenceFragmentCompat {
    @Override
    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
        setPreferencesFromResource(R.xml.preferences, rootKey);

        final EditTextPreference preference = findPreference("password");

        if (preference != null) {
            preference.setSummaryProvider(new SummaryProvider() {
                @Override
                public CharSequence provideSummary(Preference preference) {

                    String getPassword = PreferenceManager.getDefaultSharedPreferences(getContext()).getString("password", "not set");

                    //we assume getPassword is not null
                    assert getPassword != null;

                    //return "not set" else return password with asterisks
                    if (getPassword.equals("not set")) {
                        return getPassword;
                    } else {
                        return (setAsterisks(getPassword.length()));
                    }
                }
            });

            //set input type as password and set summary with asterisks the new password
            preference.setOnBindEditTextListener(
                    new OnBindEditTextListener() {
                        @Override
                        public void onBindEditText(@NonNull final EditText editText) {
                            editText.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);
                            preference.setSummaryProvider(new SummaryProvider() {
                                @Override
                                public CharSequence provideSummary(Preference preference) {
                                    return setAsterisks(editText.getText().toString().length());
                                }
                            });
                        }
                    });
        }
    }

    //return the password in asterisks
    private String setAsterisks(int length) {
        StringBuilder sb = new StringBuilder();
        for (int s = 0; s < length; s++) {
            sb.append("*");
        }
        return sb.toString();
    }
}

在 xml 中你应该有类似的内容：

<EditTextPreference
    android:dialogMessage="Enter your password"
    android:dialogTitle="Password"
    android:key="password"
    android:title="Password" />

欲了解更多信息，请查看developer.android