Warning: file_get_contents(/data/phpspider/zhask/data//catemap/7/rust/4.json): failed to open stream: No such file or directory in /data/phpspider/zhask/libs/function.php on line 167

Warning: Invalid argument supplied for foreach() in /data/phpspider/zhask/libs/tag.function.php on line 1116

Notice: Undefined index: in /data/phpspider/zhask/libs/function.php on line 180

Warning: array_chunk() expects parameter 1 to be array, null given in /data/phpspider/zhask/libs/function.php on line 181
Android 如何使用SharedReference保存和显示字符串?_Android_Sharedpreferences - Fatal编程技术网

Android 如何使用SharedReference保存和显示字符串?

Android 如何使用SharedReference保存和显示字符串?,android,sharedpreferences,Android,Sharedpreferences,我有以下代码,但应用程序强制在打开之前关闭。 我有一个编辑文本、一个按钮和一个文本视图。 单击按钮应将EditText中的字符串保存到SharedReference,并且SharedReference字符串应显示在TextView中。我做错了什么 package com.jainchiranjeev.arduinoremote.newcomponents; import android.content.SharedPreferences; import android.support.v7.a

我有以下代码,但应用程序强制在打开之前关闭。 我有一个编辑文本、一个按钮和一个文本视图。 单击按钮应将EditText中的字符串保存到SharedReference,并且SharedReference字符串应显示在TextView中。我做错了什么

package com.jainchiranjeev.arduinoremote.newcomponents;

import android.content.SharedPreferences;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;


public class MainActivity extends AppCompatActivity {

    EditText edittext;
    Button confirm;
    TextView text;

    public static final String Name = "MyPrefs";
    SharedPreferences.Editor editor = getSharedPreferences(Name, MODE_WORLD_WRITEABLE).edit();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        confirm.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                editor.putString("name", String.valueOf(edittext.getText()));
                editor.commit();
            }
        });

        SharedPreferences prefs = getSharedPreferences(Name, MODE_WORLD_READABLE);
        String restoredText = prefs.getString("name","Your name appears here");
        text.setText(restoredText);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

获取onCreateMethod中的共享首选项,不要将编辑器初始化为类的字段

SharedPreferences.Editor editor = context.getSharedPreferences(
            PREFERENCES_NAME, Context.MODE_MULTI_PROCESS | Context.MODE_PRIVATE).edit();
    editor.putString(setting, value);
    editor.apply();
也参加这次培训

初始化类后初始化prefs。你需要上下文。此外,对编辑器和编写器使用相同的pref:

SharedPreferences prefs = getSharedPreferences(Name, Context.MODE_PRIVATE);
//to write:
prefs.edit().putString("key", "value_to_save").apply();
//to read
String read = prefs.getString("key", "value_default");

但由于
editor=getSharedReferences(Name,MODE_WORLD_WRITEABLE).edit(),应用程序强制甚至在打开之前就关闭了行。要修复问题,请移动
editor=getSharedReferences(名称、模式\u WORLD\u可写)。编辑()内部
onCreate
方法