Question

制作一个包含3项活动的受人尊敬的应用程序。第三个是信使，当我按下后退按钮并返回上一个活动（第一个）时，我刚刚在edittextes中写的所有内容都被清理（文本，数字），我想使用共享首选项，任何帮助？ ``

package com.example.AzaaadCompany.mymessenger;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.telephony.SmsManager;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class thirdActivity extends AppCompatActivity {
  EditText number;
  EditText msg;
  Button btnsend;

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

    number=(EditText)this.findViewById(R.id.noteText);
    msg=(EditText)this.findViewById(R.id.editTextmsg);
    btnsend=(Button)this.findViewById(R.id.button);

    btnsend.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        String mynumber = number.getText().toString();
        String mymsg = msg.getText().toString();
        if (mynumber.length() >10 ) {
          sendMessage(mynumber, mymsg);
        } else {

        }
      }
    });
  }

  private void sendMessage(String mynumber, String mymsg){
    try {
      SmsManager smsManager = SmsManager.getDefault();
      smsManager.sendTextMessage(mynumber,null,mymsg,null,null);
      Toast.makeText(getApplicationContext(), "sent", Toast.LENGTH_LONG).show();
    } catch (Exception e){
      Toast.makeText(getApplicationContext(),"something is wrong",Toast.LENGTH_LONG).show();
      e.printStackTrace();
    }
  }
}

Answer 1

获取共享偏好

 SharedPreferences prefs = this.getSharedPreferences(
  "com.example.app", Context.MODE_PRIVATE);

将数据写入SharedPreferences

 // Writing data to SharedPreferences
 Editor editor = prefs.edit();
 editor.putString("key", "some value"); // replace 'some value' with your edit text value
 editor.putInt("your_int_key", yourIntValue);
 editor.commit();

从SharedPreferences中读取数据

 // Reading from SharedPreferences
 String value = prefs.getString("key", ""); // replace empty string with some default string (useful if key not found)
 int intValue = prefs.getInt("your_int_key", -1);

希望这有助于：）

Answer 2

写

SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPref.edit();
editor.putInt(getString(R.string.saved_high_score), newHighScore);
editor.commit();

读

SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE);
int defaultValue = getResources().getInteger(R.string.saved_high_score_default);
long highScore = sharedPref.getInt(getString(R.string.saved_high_score), defaultValue);

自： https://developer.android.com/training/basics/data-storage/shared-preferences.html

Answer 3

非常感谢每3个答案，但是你的答案有不完美之处。我用我的知识结合你的答案，这就是结果。

@覆盖 protected void onDestroy（）{

    SharedPreferences preferences = getPreferences(Context.MODE_PRIVATE);
    String name = msg.getText().toString();
    String name2 = number.getText().toString();
    SharedPreferences.Editor editor = preferences.edit();
    editor.putString("MATN",name);
    editor.putString("MATN2",name2);
    editor.commit();
    super.onDestroy();
}

@Override
protected void onResume() {
    SharedPreferences preferences = getPreferences(Context.MODE_PRIVATE);
    String value = preferences.getString("MATN2", "");
    String matn = preferences.getString("MATN","Hello"):                                   


    msg=(EditText)this.findViewById(R.id.editTextmsg);
    number=(EditText)this.findViewById(R.id.numberText);
    msg.setText(matn);
    number.setText(value);

    super.onResume();
}

}

使用共享首选项保存活动

3 个答案: