java - 字符串根本不起作用

Question

我真的不知道为什么它不显示文字。

如果您查看第 2 类，那么我会将 nimi2 保存为共享首选项。但它没有出现在第1类中。我做了一个小测试。我将名称 2 替换为“plaplapla”(注意“”)，它显示为 plaplapla。但我希望它显示任何人输入的名字。我是java新手。我再次真的没有主意了:(。有人可以帮忙吗？

package viimane.voimalus;

import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.widget.TextView;

public class MainStuff extends Activity {
    TextView tere;
    String nimi;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.menu);
        tere = (TextView) findViewById(R.id.tvTere);
        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
        boolean nimiOlemas = preferences.getBoolean("nimionolemas", false);
        nimi = preferences.getString("nimi2", "");
        if (nimiOlemas == false){
             startActivityForResult(new Intent(this, nimekysija.class), 0);
             finish();
        }
        if (nimiOlemas == true){
            tere.setText("Tere " + nimi);
        }

    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // get data from shared preference here
        super.onActivityResult(requestCode, resultCode, data);
    }
}

<小时/>

package viimane.voimalus;

import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class nimekysija extends Activity {

    EditText nimi;
    SharedPreferences preferences;
    String nimi2;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.nimekysija);
        preferences = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
        nimi = (EditText) findViewById(R.id.etNimekysija);
        nimi2 = nimi.getText().toString();
        Button kysOk = (Button) findViewById(R.id.bNimekysija);
        kysOk.setOnClickListener(new View.OnClickListener() {      

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub

                SharedPreferences.Editor editor = preferences.edit();
                editor.putString("nimi2", nimi2); // nime kirjutamine
                editor.putBoolean("nimionolemas", true); // nimi on kirjutatud!
                editor.commit();
                startActivity(new Intent("viimane.voimalus.MAINSTUFF"));
                finish();

            }
        });
    }

}

<小时/>

and XML

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    <TextView android:text="" android:id="@+id/tvTere" android:layout_width="fill_parent" android:layout_height="wrap_content"></TextView>
</LinearLayout>

<小时/>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="match_parent"
  android:layout_height="match_parent">
    <TextView android:text="Palun sisestage oma nimi!" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center"></TextView>
    <EditText android:id="@+id/etNimekysija" android:layout_height="wrap_content" android:layout_width="fill_parent">
    </EditText>
    <Button android:text="OK!" android:id="@+id/bNimekysija" android:layout_width="fill_parent" android:layout_height="wrap_content" android:onClick="onAddClick"></Button>

</LinearLayout>

Answer 1

不要使用 startActivity()，而是使用名为 startActivityForResult() 的方法。在类 1 中重写另一个名为 onActivityResult() 的方法，在该方法中您尝试获取 String。现在，您正在尝试从 sharedPreference 获取值，然后再将其存储在 class2 中。

//已编辑

package viimane.voimalus;

import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.widget.TextView;

public class MainStuff extends Activity {
    TextView tere;
    String nimi;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.menu);
        tere = (TextView) findViewById(R.id.tvTere);
        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
        boolean nimiOlemas = preferences.getBoolean("nimionolemas", false);
        if (nimiOlemas == false){
             startActivity(new Intent("viimane.voimalus.NIMEKYSIJA"));
             finish();
        }
        if (nimiOlemas == true){
            nimi = preferences.getString("nimi2", "");
            System.out.print("töötab!");

            tere.setText("Tere " + nimi);
        }
        System.out.print("töötab2!");
    }
@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // get data from shared preference here
        super.onActivityResult(requestCode, resultCode, data);
    }
}

编辑:我不小心编辑了它。现已修复