问题描述

andriod gridview 空指针异常

package com.example.weishi03;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Intent;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import com.example.weishi03.utils.Md5;
import com.example.weishi03.utils.MyConstant;
import com.example.weishi03.utils.SpTool;

public class HomeActivity extends Activity {

private int[] icons = {R.drawable.oneR.drawable.twoR.drawable.three        R.drawable.fourR.drawable.fiveR.drawable.six        R.drawable.sevenR.drawable.eightR.drawable.nine};private String[] names = {""one""two""three""four""five""six""seven""eight""nine""};private GridView gv;private MyAdapter adapter;  private AlertDialog dialog;@Overrideprotected void onCreate(Bundle savedInstanceState) {    // TODO Auto-generated method stub    super.onCreate(savedInstanceState);    initView();    initData();    initEvent();}private void initEvent() {    gv.setOnItemClickListener(new OnItemClickListener() {        @Override        public void onItemClick(AdapterView<?> parent View view                int position long id) {            switch (position) {            case 0:                if (TextUtils.isEmpty(SpTool.getString(getApplicationContext() MyConstant.PASSWORD"))){                    showSetPassWord();                }else {                    showEnterPassWord();                }                break;            default:                break;            }        }    });}protected void showEnterPassWord() {    AlertDialog.Builder ab = new AlertDialog.Builder(this);    View view =View.inflate(getApplicationContext() R.layout.dialog_enterpass null);    final EditText pass = (EditText) findViewById(R.id.et_dialogenterpassword_pass);    Button confim = (Button) findViewById(R.id.bt_dialogenterpassword_confim);    Button cancel = (Button) findViewById(R.id.bt_dialogenterpassword_cancel);    ab.setView(view);    confim.setOnClickListener(new OnClickListener() {        @Override        public void onClick(View v) {            String passWord = pass.getText().toString();            String truePass = SpTool.getString(getApplicationContext() MyConstant.PASSWORD");            passWord = Md5.md5(Md5.md5(passWord));            if (passWord == null || passWord != truePass ) {                Toast.makeText(getApplicationContext()Wrong pass"" 1).show();                return;            }else {                Intent intent = new Intent(HomeActivity.thisLostFindActivity.class);                startActivity(intent);            }            dialog.dismiss();        }    });    cancel.setOnClickListener(new OnClickListener() {        @Override        public void onClick(View v) {            dialog.dismiss();        }    });    dialog = ab.create();    dialog.show();}protected void showSetPassWord() {    AlertDialog.Builder ab = new AlertDialog.Builder(this);    View view = View.inflate(getApplicationContext() R.layout.dialog_setpass null);    final EditText et_passone = (EditText) findViewById(R.id.et_dialogsetpass_passone);    final EditText et_passtwo = (EditText) findViewById(R.id.et_dialogsetpass_passtwo);    Button bt_confim = (Button) findViewById(R.id.bt_dialogsetpass_confim);    Button bt_cancel = (Button) findViewById(R.id.bt_dialogsetpass_cancel);    ab.setView(view);    bt_confim.setOnClickListener(new OnClickListener() {        @Override        public void onClick(View v) {            String passone = et_passone.getText().toString().trim();            String passtwo = et_passtwo.getText().toString().trim();            if (passone.equals("""") || passtwo.equals("""")) {                Toast.makeText(getApplicationContext()Pass is null"" 1).show();                return;            }else if (!passone.equals(passtwo)) {                Toast.makeText(getApplicationContext()Pass is nu"" 1).show();                return;            }else {                passone = Md5.md5(Md5.md5(passone));                SpTool.putString(getApplicationContext() MyConstant.PASSWORD passone);                dialog.dismiss();            }        }    });    bt_cancel.setOnClickListener(new OnClickListener() {        @Override        public void onClick(View v) {            dialog.dismiss();        }    });    dialog = ab.create();    dialog.show();}private void initData() {    adapter = new MyAdapter();    gv.setAdapter(adapter);}private class MyAdapter extends BaseAdapter{    @Override    public int getCount() {        return icons.length;    }    @Override    public View getView(int position View convertView ViewGroup parent) {        View view = View.inflate(getBaseContext() R.layout.item_gridview null);        ImageView iv = (ImageView) findViewById(R.id.iv_item_gridview_icon);        TextView tv = (TextView) findViewById(R.id.tv_item_gridview_name);        iv.setImageResource(icons[position]);        tv.setText(names[position]);        return view;    }    @Override    public Object getItem(int position) {        // TODO Auto-generated method stub        return null;    }    @Override    public long getItemId(int position) {        // TODO Auto-generated method stub        return 0;    }}private void initView() {    setContentView(R.layout.activity_home);    gv = (GridView) findViewById(R.id.gv_home_gridview);}

}

上面的代码我是按照视频里敲的但是在 iv.setImageResource(icons[position]);这里报空指针异常我该怎么改?

解决方案

 View view = View.inflate(getBaseContext() R.layout.item_gridview null);        ImageView iv = (ImageView) findViewById(R.id.iv_item_gridview_icon);        TextView tv = (TextView) findViewById(R.id.tv_item_gridview_name);    改成    View view = View.inflate(getBaseContext() R.layout.item_gridview null);        ImageView iv = (ImageView)view.findViewById(R.id.iv_item_gridview_icon);        TextView tv = (TextView) view.findViewById(R.id.tv_item_gridview_name);

解决方案二：
太粗心了.多谢danielinbiti