android - 在适配器中启动 Intent

Question

我想从这个基础适配器开始一个新的 Activity 。

public class EfficientAdapter extends BaseAdapter {

    private Activity activity;
    private ArrayList<ComptePost> data;
    private static LayoutInflater inflater = null;
    public ImageLoader imageLoader; 
    public  Boolean isActusAstuce;
    public static int flag = 0, counter=0;

    private Context context;

    public EfficientAdapter(Context context) {
        this.context = context;     
    }

    NVirementEmmeteur main;

    int num = 0;

    ViewHolder holder;
    static String src;

    public EfficientAdapter(Activity a, ArrayList<ComptePost> d) {
        activity = a;
        data = d;
        inflater = (LayoutInflater) activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        //  imageLoader = new ImageLoader(activity.getApplicationContext());
        imageLoader=new ImageLoader(activity.getApplicationContext());
    }

    public EfficientAdapter(NVirementEmmeteur m) {
        main = m;
    }

    @Override
    public int getCount() {
        return data.toArray().length;
    }

    @Override
    public Object getItem(int position) {
        return position;
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    public static class ViewHolder {
        public TextView one;
        public TextView two;
        public TextView three;
        public ImageView image;
        public RelativeLayout relative_layout;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        View vi = convertView;
        holder.relative_layout.setOnClickListener(new OnClickListener(){

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                v.getContext().startActivity(new Intent(context, NVirementEmmeteur.class)); 
            }
        });
        return vi;
    }
}

我试过了

context.startActivity(new Intent(context, NVirementEmmeteur.class));

和

v.getContext().startActivity(new Intent(context, NVirementEmmeteur.class));

但它强制关闭了我的应用程序。

Intent 应该在列表适配器的 onclicklistener() 中启动。有人可以告诉我如何从我的 efficientadapter.class 启动一个 intent。

这是我的 logcat 输出:

04-11 10:07:50.878: E/AndroidRuntime(11179): FATAL EXCEPTION: main 04-11 10:07:50.878: E/AndroidRuntime(11179): java.lang.NullPointerException 04-11 10:07:50.878: E/AndroidRuntime(11179): at android.content.ComponentName.(ComponentName.java:75) 04-11 10:07:50.878: E/AndroidRuntime(11179): at android.content.Intent.(Intent.java:2863) 04-11 10:07:50.878: E/AndroidRuntime(11179): at.adapter.EfficientAdapter$1.onClick(EfficientAdapter.java:141) 04-11 10:07:50.878: E/AndroidRuntime(11179): at android.view.View.performClick(View.java:2538) 04-11 10:07:50.878: E/AndroidRuntime(11179): at android.view.View$PerformClick.run(View.java:9152) 04-11 10:07:50.878: E/AndroidRuntime(11179): at android.os.Handler.handleCallback(Handler.java:587) 04-11 10:07:50.878: E/AndroidRuntime(11179): at android.os.Handler.dispatchMessage(Handler.java:92) 04-11 10:07:50.878: E/AndroidRuntime(11179): at android.os.Looper.loop(Looper.java:130) 04-11 10:07:50.878: E/AndroidRuntime(11179): at android.app.ActivityThread.main(ActivityThread.java:3687) 04-11 10:07:50.878: E/AndroidRuntime(11179): at java.lang.reflect.Method.invokeNative(Native Method) 04-11 10:07:50.878: E/AndroidRuntime(11179): at java.lang.reflect.Method.invoke(Method.java:507) 04-11 10:07:50.878: E/AndroidRuntime(11179): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:842) 04-11 10:07:50.878: E/AndroidRuntime(11179): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600) 04-11 10:07:50.878: E/AndroidRuntime(11179): at dalvik.system.NativeStart.main(Native Method)

Answer 1

您已经在构造函数中传递了 Activity 上下文，因此您也可以使用；

activity.startActivity(new Intent(activity, NVirementEmmeteur.class));

---

检查这里是示例代码，您知道该怎么做:

像这样设置适配器:adapter = new MyArrayAdapter(MainActivity.this, COUNTRIES);

适配器代码:

package com.example.testapp;

import com.example.main.util.testActivity;

import android.content.Context;
import android.content.Intent;
import android.text.Html;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

class MyArrayAdapter extends BaseAdapter {

    private LayoutInflater mInflater;
    private Context mcon;
    private String[] COUNTRIES_;

    public MyArrayAdapter(Context con, String[] countries) {
        // TODO Auto-generated constructor stub
        mcon = con;
        COUNTRIES_ = countries;
        mInflater = LayoutInflater.from(con);
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return COUNTRIES_.length;
    }

    @Override
    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return position;
    }

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        final ListContent holder;
        View v = convertView;
        if (v == null) {
            v = mInflater.inflate(R.layout.my_spinner_style, null);
            holder = new ListContent();
            holder.line = (LinearLayout) v.findViewById(R.id.line_);
            holder.name = (TextView) v.findViewById(R.id.textView1);
            holder.name1 = (TextView) v.findViewById(R.id.textView2);
            holder.name2 = (ImageView) v.findViewById(R.id.imageView1);

            v.setTag(holder);
        } else {

            holder = (ListContent) v.getTag();
        }

        holder.name.setText("" + Html.fromHtml("" + COUNTRIES_[position]));
        holder.name1.setText("" + Html.fromHtml("" + COUNTRIES_[position]));

        holder.line.setOnClickListener(new OnClickListener() {

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

                mcon.startActivity(new Intent(mcon, testActivity.class));
            }
        });

        return v;
    }

}

class ListContent {

    TextView name;
    TextView name1;
    ImageView name2;
    LinearLayout line;

}

---

已编辑:

如果您使用此构造函数:则 list.setadapter(new EfficientAdapter(myactivity.this));

public EfficientAdapter(Context context) {
          this.context = context;     
     }

然后使用:context.startActivity(new Intent(context, NVirementEmmeteur.class));

---

如果你使用这个构造函数 list.setadapter(new EfficientAdapter(myactivity.this, ComptePostarray));

public EfficientAdapter(Activity a, ArrayList<ComptePost> d) {

        activity = a;
        data = d;
        inflater = (LayoutInflater) activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    //  imageLoader = new ImageLoader(activity.getApplicationContext());
        imageLoader=new ImageLoader(activity.getApplicationContext());
    }

然后使用 activity.startActivity(new Intent(activity, NVirementEmmeteur.class));

希望你明白....