切换紧凑型 Android SharedPreferences 不起作用答案

【问题标题】：Switch compact Android SharedPreferences is not working切换紧凑型 Android SharedPreferences 不起作用
【发布时间】：2019-03-14 06:53:24
【问题描述】：

以下代码中的SharedPreferences 不能按要求工作。我哪里错了？ SharedPreferences 在点击时保存，同样是在我的 Android 活动中检索 OnCreate 和 OnResume 的值。

代码：

mySwitch = (SwitchCompat) findViewById(R.id.atten);
strttime = (TextView) findViewById(R.id.textView5);
endtime = (TextView) findViewById(R.id.textView6);
SharedPreferences settings = getSharedPreferences(PREFS_NAME, MODE_PRIVATE);
silent = settings.getBoolean("switchkey", false);
mySwitch.setChecked(silent);

mySwitch.setOnClickListener(new View.OnClickListener() {

    @Override
    public void onClick(View v) {
        final SwitchCompat btn = (SwitchCompat) v;
        final boolean switchChecked = silent;

        String message = "Are you sure you want to Logout?";
        if (!btn.isChecked()) {
            message = "Are you sure you want to Login?";
        }
        AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this, R.style.MyAlertDialogStyle); // Change "this" to `getActivity()` if you're using this on a fragment
        builder.setMessage(message).setPositiveButton("Ok", new DialogInterface.OnClickListener() {@Override
            public void onClick(DialogInterface dialog, int i) {
                // "Yes" button was clicked
                if (switchChecked) {

                    Log.d("You are :", "Checked");

                    SharedPreferences settings = getSharedPreferences(PREFS_NAME, MODE_PRIVATE);
                    SharedPreferences.Editor editor = settings.edit();
                    editor.putBoolean("switchkey", true);
                    editor.apply();
                } else {
                    SharedPreferences settings = getSharedPreferences(PREFS_NAME, MODE_PRIVATE);
                    SharedPreferences.Editor editor = settings.edit();
                    editor.putBoolean("switchkey", false);
                    editor.apply();
                }
            }
        }).setNegativeButton("Cancel", null).show();
    }
});

【问题讨论】：

您忘记提及在onCreate 或onResume 中由sharedperference 保存的错误值在哪里

标签： android sharedpreferences android-switch

【解决方案1】：

这是因为final boolean switchChecked = silent; 在您的setOnClickListener 中发生的

您在switchChecked 中保持沉默，因此沉默总是错误的 silent = settings.getBoolean("switchkey", false);（如果没有可用值）

所以你所要做的就是像这样在switchChecked 中传递正确的值

final boolean switchChecked = btn.isChecked();

因为您需要检查用户是否按下了您的开关

现在switchChecked 将根据用户输入具有正确的值

所以你的代码将是

  mySwitch = (SwitchCompat) findViewById(R.id.atten);
    strttime = (TextView) findViewById(R.id.textView5);
    endtime = (TextView) findViewById(R.id.textView6);
    SharedPreferences settings = getSharedPreferences(PREFS_NAME, MODE_PRIVATE);
    silent = settings.getBoolean("switchkey", false);
    mySwitch.setChecked(silent);

    mySwitch.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            final SwitchCompat btn = (SwitchCompat) v;
            final boolean switchChecked = btn.isChecked();

            String message = "Are you sure you want to Logout?";
            if (!btn.isChecked()) {
                message = "Are you sure you want to Login?";
            }
            AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
            builder.setMessage(message)
                    .setPositiveButton("Ok", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int i) {
                            // "Yes" button was clicked
                            if (switchChecked) {

                                Log.d("You are :", "Checked");

                                SharedPreferences settings = getSharedPreferences(PREFS_NAME, MODE_PRIVATE);
                                SharedPreferences.Editor editor = settings.edit();
                                editor.putBoolean("switchkey", true);
                                editor.apply();
                            } else {
                                SharedPreferences settings = getSharedPreferences(PREFS_NAME, MODE_PRIVATE);
                                SharedPreferences.Editor editor = settings.edit();
                                editor.putBoolean("switchkey", false);
                                editor.apply();
                            }

                        }
                    })
                    .setNegativeButton("Cancel", null)
                    .show();

        }

    });

【讨论】：

这修复了它！

【解决方案2】：

为什么您似乎有两个不同的SwitchCompat 视图，分别称为mySwitch 和btn？很难说你想要完成什么。

无论如何，试试这个来获取SwitchCompat的状态：

builder.setMessage(message)
                .setPositiveButton("Ok", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int i) {
                        SharedPreferences settings = getSharedPreferences(PREFS_NAME, MODE_PRIVATE);
                        SharedPreferences.Editor editor = settings.edit();
                        editor.putBoolean("switchkey", mySwitch.isChecked());
                        //or maybe you want btn.isChecked()? I don't know
                        editor.apply();
                    }

【讨论】：