将数据从第二个 activity 传递到第三个 activity

Question

在这个程序中，我有三个活动 Main、Second 和 Third。当应用程序打开时，有一个空白的文本视图和按钮。选择该按钮会将您带到第二个 activity，用户可以在其中输入姓名、phone 号码和电子邮件地址。填写完这些表格后，用户将点击一个按钮来存储该信息并将它们带回主 activity。当返回主 activity 时，用户将看到他们输入的名称显示在曾经空白的文本视图中。然后，他们可能 select 文本视图会将他们带到第三个 activity，显示他们在第二个 activity 中输入的姓名、phone 号码和电子邮件地址。

除了将数据从第二个 activity 传递到第三个之外，我一切正常。我做了一些研究，发现可以使用捆绑包和共享首选项做很多事情。我对他们不太熟悉，因为这对我来说很陌生。我确实尝试过实施它们，但没有任何运气。无论如何，代码在下面，我们将不胜感激任何帮助、反馈或指导。先感谢您！

主要Activity:

public class MainActivity extends AppCompatActivity {

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

}
  public void onClick(View view){ 
     startActivityForResult(new Intent(getApplicationContext(),SecondActivity.class),999);
}

public void onClickText(View v)
{ 
    startActivityForResult(new Intent(getApplicationContext(),ThirdActivity.class),999);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
   super.onActivityResult(requestCode, resultCode, data);
    if(requestCode == 999 && resultCode == RESULT_OK)
    { TextView contactView = (TextView) findViewById(R.id.contactDisplay);
      contactView.setText(data.getStringExtra("Name"));

    }


}}

第二个Activity:

public class SecondActivity extends AppCompatActivity {
public String textName;
public String emailAddress;
public int phoneNumber;
private TextView textNameView2;
EditText textPersonName;
EditText number;
EditText textEmailAddress;


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

}


public void onClickTwo(View view)
{
    textPersonName = (EditText) findViewById(R.id.name);
    number = (EditText) findViewById(R.id.number);
    textEmailAddress = (EditText) findViewById(R.id.email);

    textName = textPersonName.getText().toString();
    emailAddress = textEmailAddress.getText().toString();
    phoneNumber = Integer.valueOf(number.getText().toString());
    showToast(textName +"added");


    Intent backMain = new Intent(this, MainActivity.class);
   // Intent backMain = new Intent();
    backMain.putExtra("Name",textName);
   // backMain.putExtra("Email", emailAddress);
   // backMain.putExtra("Phone", phoneNumber);
    setResult(RESULT_OK, backMain);

    Intent thirdMain = new Intent(this, ThirdActivity.class);
    thirdMain.putExtra("Name",textName);
    thirdMain.putExtra("Email",emailAddress);
    thirdMain.putExtra("Phone",phoneNumber);
    setResult(RESULT_OK,thirdMain);
    finish();
}

private  void showToast(String text)
{
    Toast.makeText(this,text, Toast.LENGTH_LONG).show();

}}

第三个Activity:

public class ThirdActivity extends AppCompatActivity {

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

}


   protected void onActivityResult(int requestCode, int resultCode, Intent data){
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == 999 && resultCode == RESULT_OK) {

            TextView contact = (TextView) findViewById(R.id.contactNameView);
            contact.setText(data.getStringExtra("Name"));

            TextView phone = (TextView) findViewById(R.id.phoneView);
           phone.setText(data.getStringExtra("Phone"));

            TextView email = (TextView) findViewById(R.id.emailView);
            email.setText(data.getStringExtra("Email"));
        }

}
}

Answer 1

关注此线程，了解使用 intent 在活动之间传递数据：

How do I pass data between Activities in Android application?

但是，如果您想使用共享首选项传递数据，请使用此代码段：

public class SharedPreferenceManager {
    private static final String PREFS_NAME = Config.SHARED_PREF_NAME;

    /**
     * @param context
     * @param key
     * @param value
     * @return
     */
    public static boolean saveToPreference(Context context, String key, String value) {
        SharedPreferences settings = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = settings.edit();
        editor.putString(key, value);
        return editor.commit();
    }


    /**
     * @param context
     * @param key
     * @return
     */
    public static String loadFromPreference(Context context, String key) {
        SharedPreferences settings = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
        return settings.getString(key, "");
    }
}

要保存到首选项，您需要传入应用程序上下文、要保存的键和字符串。要从 SharedPreference 加载已保存的字符串，您传入 Context 和 activity 中的 Key 假设我想在一个 activity 中将字符串电子邮件保存到我的共享首选项，然后将其加载到另一个 activity 中，这是我会怎么做：

//Save to shared Preference in Activity A
SharedPreferenceManager.saveToPreference(this, "email", emailAddress.getText().toString());

//Load from shared preference in activity b
String emailAddress = SharedPreferenceManager.loadFromPreference(this, "email");

将数据从第二个 activity 传递到第三个 activity

Passing data from second activity to third activity

java

android

user-input

textview

android-activity