【问题标题】:how to use if in click listener for go different activity?如何在点击侦听器中使用 if 进行不同的活动?
【发布时间】:2013-12-21 17:46:48
【问题描述】:

我的应用程序的第一页有搜索栏,当我写到搜索栏打开搜索助手(帮助列表视图)时,我想单击列表视图的每个项目以转到不同的活动。

问题:我不知道在此列表视图中使用if 来进行其他活动。我测试了这段代码,但只是在第一个 if 中进行了第一个活动。

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.SimpleAdapter;
import android.widget.TextView;


public class MainActivity extends Activity {

    ArrayList<HashMap<String,String>> adp;
    // Array of strings storing country names
    String[] countries = new String[] {
            "India",
            "Pakistan",
            "Sri Lanka",
            "China",
            "Bangladesh",
            "Nepal",
            "Afghanistan",
            "North Korea",
            "South Korea",
            "Japan"
    };

 // Array of integers points to images stored in /res/drawable-ldpi/
    int[] flags = new int[]{
                R.drawable.india,
                R.drawable.pakistan,
                R.drawable.srilanka,
                R.drawable.china,
                R.drawable.bangladesh,
                R.drawable.nepal,
                R.drawable.afghanistan,
                R.drawable.nkorea,
                R.drawable.skorea,
                R.drawable.japan
    };

    // Array of strings to store currencies
    String[] currency = new String[]{
        "Indian Rupee",
        "Pakistani Rupee",
        "Sri Lankan Rupee",
        "Renminbi",
        "Bangladeshi Taka",
        "Nepalese Rupee",
        "Afghani",
        "North Korean Won",
        "South Korean Won",
        "Japanese Yen"
    };




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


        // Each row in the list stores country name, currency and flag
        List<HashMap<String,String>> aList = new ArrayList<HashMap<String,String>>();


        for(int i=0;i<10;i++){
                HashMap<String, String> hm = new HashMap<String,String>();
            hm.put("txt", countries[i]);
            hm.put("flag", Integer.toString(flags[i]) );
            hm.put("cur", currency[i]);
            aList.add(hm);
        }

        // Keys used in Hashmap
        String[] from = { "flag","txt"};

        // Ids of views in listview_layout
        int[] to = { R.id.flag,R.id.txt};

        // Instantiating an adapter to store each items
        // R.layout.listview_layout defines the layout of each item
        SimpleAdapter adapter = new SimpleAdapter(getBaseContext(), aList, R.layout.autocomplete_layout, from, to);

        // Getting a reference to CustomAutoCompleteTextView of activity_main.xml layout file
        CustomAutoCompleteTextView autoComplete = ( CustomAutoCompleteTextView) findViewById(R.id.autocomplete);

        /** Defining an itemclick event listener for the autocompletetextview */
        OnItemClickListener itemClickListener = new OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {


            if(parent.getAdapter().getItem(position).equals("India")){
                    Intent intent = new Intent(MainActivity.this, TestPage.class);
                    startActivity(intent);
                } else if(parent.getAdapter().getItem(position).equals("Pakistan")){
                    Intent intent = new Intent(MainActivity.this, TestPage2.class);
                    startActivity(intent);
                }


            }
        };

        /** Setting the itemclick event listener */
        autoComplete.setOnItemClickListener(itemClickListener);

        /** Setting the adapter to the listView */
        autoComplete.setAdapter(adapter);

    }

    /** A callback method, which is executed when this activity is about to be killed
     * This is used to save the current state of the activity 
     * ( eg :  Configuration changes : portrait -> landscape )  
     */
    @Override
    protected void onSaveInstanceState(Bundle outState) {
        TextView tvCurrency = (TextView) findViewById(R.id.tv_currency) ;       
        outState.putString("currency", tvCurrency.getText().toString());
        super.onSaveInstanceState(outState);
    }

    /** A callback method, which is executed when the activity is recreated 
     * ( eg :  Configuration changes : portrait -> landscape )  
     */
    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        TextView tvCurrency = (TextView) findViewById(R.id.tv_currency) ;       
        tvCurrency.setText(savedInstanceState.getString("currency"));
        super.onRestoreInstanceState(savedInstanceState);
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }
}

【问题讨论】:

  • 如果您单击巴基斯坦的列表项会发生什么?
  • 你应该首先检查getItem()的返回类型。它会返回您认为它返回的项目吗?
  • 我怎样才能在我的代码中使用 getitem(),你到底是什么意思,对不起,我是 eclipse 的新手

标签: listview android-intent android-listview android


【解决方案1】:

在您的列表视图中,由于您使用的是自定义适配器,我可以看到在哈希图中,您添加了三个东西,因此您应该在列表视图的onItemClick 侦听器中使用contains 方法

您的代码是文件。 将equals 替换为contains

【讨论】:

  • 测试过了,但是不行。搜索项目后点击项目跳转应用
  • 首先调试你的应用程序,或者将整个项目粘贴到某个地方。我去看看
【解决方案2】:

自定义列表视图将不支持您正在使用的 onitemclicklistner。如果您在每行的 baseadapter 中调用 setonclicklistner 会更好。这将完美地工作。请尝试一下,如果您需要更多帮助,请告诉我。谢谢

【讨论】:

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