从另一个 activity 接收共享 SharedPreferences 值的值

Question

我有这段代码可以从 edittext 中获取 SharedPreferences 的值，然后将它发送给其他人 activity 不知何故我无法从其他人那里使用它 activity 我在代码中遗漏的任何建议提前致谢

-那是我的第一个 activity，用于从 edittext 获取 SharedPreferences，我想将值从它发送到第二个 activity

public class NationalId extends Activity {
public static final String MyPREFERENCES = "MyPrefs" ;
public static final String Name = "nameKey";
SharedPreferences sharedpreferences;

final Context context = this;
private Button button;
private TextView result;

public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_national_id);

    // components from main.xml
    button = (Button) findViewById(R.id.button1);
    result = (TextView) findViewById(R.id.tv1);
    sharedpreferences = getSharedPreferences(MyPREFERENCES, Context.MODE_PRIVATE);

    // add button listener
    button.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View arg0) {


            // get prompts.xml view
            LayoutInflater li = LayoutInflater.from(context);
            View promptsView = li.inflate(R.layout.prompts, null);

            android.app.AlertDialog.Builder alertDialogBuilder = new android.app.AlertDialog.Builder(
                    context);

            // set prompts.xml to alertdialog builder
            alertDialogBuilder.setView(promptsView);

            final EditText userInput = (EditText) promptsView
                    .findViewById(R.id.editTextDialogUserInput);

            alertDialogBuilder
                    .setCancelable(false)
                    .setPositiveButton("OK",
                            new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog,int id) {
                                    String n  = userInput.getText().toString();
                                    SharedPreferences.Editor editor = sharedpreferences.edit();
                                    editor.putString(Name, n);
                                    editor.commit();
                                    // edit text
                                    result.setText(userInput.getText());
                                    Toast.makeText(NationalId.this,"saved:"+n,Toast.LENGTH_LONG).show();

                                }
                            })
                    .setNegativeButton("Cancel",
                            new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog,int id) {
                                    dialog.cancel();
                                }
                            });

            // create alert dialog
            android.app.AlertDialog alertDialog = alertDialogBuilder.create();

            // show it
            alertDialog.show();

        }
    });
}
}

这里是我想要的第二个 activity 在

中接收值

public class receive extends Activity {



private Button button;
private EditText etPhoneno;

public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_opreator_mobily);
    button = (Button) findViewById(R.id.buttonCall);
    etPhoneno = (EditText) findViewById(R.id.editText1);
    SharedPreferences prefs = getSharedPreferences("Name",
            MODE_PRIVATE);
    final String value = prefs.getString("n", "0");
    // add button listener\
    button.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View arg0) {

            Toast.makeText(receive.this,"saved:"+value,Toast.LENGTH_LONG).show();


        }
    });
}

}

Answer 1

在你的第二个 activity 中，你试图用不同的名称获取你的 sharedpreferences 实例，并用不同的键获取你保存的值。

替换为：

SharedPreferences prefs = getSharedPreferences("Name", MODE_PRIVATE);
final String value = prefs.getString("n", "0");

和

SharedPreferences prefs = getSharedPreferences("MyPrefs", MODE_PRIVATE);
final String value = prefs.getString("nameKey", "0");

Answer 2

替换下面这两行

SharedPreferences prefs = getSharedPreferences("Name",MODE_PRIVATE);
    final String value = prefs.getString("n", "0");

这些行

SharedPreferences prefs = getSharedPreferences("MyPrefs", MODE_PRIVATE);
final String value = prefs.getString("nameKey", "0");

从另一个 activity 接收共享 SharedPreferences 值的值

receive value of shared SharedPreferences value from another activity

android

sharedpreferences

android-sharedpreferences