Question

我正在开发应用程序，其中我想在列表视图中显示一些引号和语句，并且还希望在用户单击列表项时显示新布局文件中的每个引号。这是我的主要活动代码与简单列表视图： -

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;

/**
 * Created by Tauseef on 11/11/2015.
 */
public class MainActivity extends AppCompatActivity {

    private String[] loveArray = { 
            "Jo Pyar Hamesha Sath Rahe Wo Sacha Hai Ji,\n" +
            "Jo Musibaton Mein Kaam Aaye Wo Acha Hai Ji,\n" +
            "Kabhi Kabhi Humse Bhi Ho Jati Hai Nadaniya,\n" +
            "Kyonki Dil To Baccha Hai Ji.", "Chor to sakta hu,\n" +
            "Magar Chor nahipate use,\n" +
            "Wo shaks meri bigri huyi,\n" +
            "Aadat ki trha hai.", 

            "Ek shaam aati hai tumhari yaad lekar,\n" +
            "Ek shaam jaati hai tumhari yaad dekar,\n" +
            "Par hume intezaar hai us shaam ka,\n" +
            "Jo aaye sirf tumhe saath lekar" 
};

    private ListView loveListView;
    private ArrayAdapter arrayAdapter;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_love);

        Intent intent = getIntent();

        loveListView = (ListView) findViewById(R.id.loveList);

        // this-The current activity context.
        // Second param is the resource Id for list layout row item
        // Third param is input array
        arrayAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, loveArray);
        loveListView.setAdapter(arrayAdapter);

        loveListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {                      

                Intent newIntent = new Intent(LoveActivity.this, MainContent.class);
                newIntent.putExtra("loveArray", position);
                startActivity(newIntent);
            }
        });
    }
}

以下是仅包含textview的新活动，我想在其中将所点击的列表项目显示为textView： -

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;

/**
 * Created by Tauseef on 11/11/2015.
 */
public class MainContent extends AppCompatActivity {

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

        TextView textView =(TextView)findViewById(R.id.mainContentTextView);
        Intent intent = getIntent();
        String data = "";
        if(intent!= null){
            Bundle extras = intent.getExtras();
            if(extras != null){
                data = extras.getString("loveArray");
            }
        }
            }
}

每当我运行这个应用程序并点击列表项时，它会显示空指针和其他一些东西。我没有得到这个代码中实际出现的错误。

Answer 1

你的爱情阵应该有多个项目。因此，当您通过单击listview启动活动时，它应该采取位置数组，以便更改

newIntent.putExtra("loveArray", position);

到

newIntent.putExtra("loveArray", loveArray[position]);

所以它需要位置数据的数据

Answer 2

Bundle extras = intent.getExtras();
            if(extras != null){
                data = extras.getInt("loveArray");
            }

并使用getInt("loveArray")代替getString()

Bçoz你传递的位置，即int

Intent newIntent = new Intent(LoveActivity.this, MainContent.class);
newIntent.putExtra("loveArray", position);//Int not string

修改 如果您传递引用消息而不是位置，请在下方使用。

Intent newIntent = new Intent(LoveActivity.this, MainContent.class);
newIntent.putExtra("loveArray", loveArray [position]);// Pass the quote as string

然后

data = extras.getString("loveArray");将有效

Answer 3

问题来自您传递整数（位置）值的MainActivity活动，以及您收到字符串值的MainContent活动。你需要写

data = extras.getInt("loveArray");

墨水瓶架

data = extras.getString("loveArray");

Answer 4

按照以下步骤

不要仅传递位置，只需通过执行

传递String

Intent intent = new Intent(LoveActivity.this, MainContent.class);
intent.putExtra("loveArray", loveArray[position]);// this will pass the string of this position`

然后在MainContent Activity中，执行

data= extras.getString("loveArray"); 它必须工作`

如何通过单击在新布局中显示Android ListView项目

4 个答案: