android 35 ListView增删改差

MainActivity

package com.sxt.day05_11;

import java.util.ArrayList;

import java.util.List;

import android.app.Activity;

import android.app.AlertDialog;

import android.content.DialogInterface;

import android.content.Intent;

import android.content.DialogInterface.OnClickListener;

import android.os.Bundle;

import android.view.View;

import android.view.ViewGroup;

import android.widget.AdapterView;

import android.widget.AdapterView.OnItemLongClickListener;

import android.widget.BaseAdapter;

import android.widget.ImageView;

import android.widget.ListView;

import android.widget.TextView;

import com.sxt.day05_11.entity.GeneralBean;

public class MainActivity extends Activity {

    ListView mlvGeneral;

    List<GeneralBean> mGenerals;

    GeneralAdapter mAdapter;

    private static final int ACTION_DETAILS=0;

    private static final int ACTION_ADD=1;

    private static final int ACTION_DELETE=2;

    private static final int ACTION_UPDATE=3;

    int mPosition;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        initData();

        initView();

        setListener();

    }

    private void setListener() {

        mlvGeneral.setOnItemLongClickListener(new OnItemLongClickListener() {

            @Override

            public boolean onItemLongClick(AdapterView<?> parent, View view,

                    final int position, long id) {

                AlertDialog.Builder builder=new AlertDialog.Builder(MainActivity.this);

                builder.setTitle("选择以下操作")

                    .setItems(new String[]{"查看详情","添加数据","删除数据","修改数据"}, new OnClickListener() {//倒的包是import android.content.DialogInterface.OnClickListener;

                        @Override

                        public void onClick(DialogInterface dialog, int which) {

                            switch (which) {

                            case ACTION_DETAILS:

                                showDetails(position);//这个position在mGenerals.get(position);调用，说明position是资源总条数范围，

                                break;

                            case ACTION_ADD:

                                break;

                            case ACTION_DELETE:

                                mAdapter.remove(position);//调用适配器的删除方法

                                break;

                            case ACTION_UPDATE:

                                //启动修改的Activity，并将当前的军事家对象传递过去

                                Intent intent=new Intent(MainActivity.this, UpdateActivity.class);

                                intent.putExtra("general", mGenerals.get(position));//mGenerals.get(position)的对象要实现序列化接口

                                mPosition=position;

                                startActivityForResult(intent, ACTION_UPDATE);//要求返回结果，ACTION_UPDATE是requestCode

                                break;

                            }

                        }

                        private void showDetails(int position) {

                            GeneralBean general=mGenerals.get(position);

                            AlertDialog.Builder builder=new AlertDialog.Builder(MainActivity.this);

                            builder.setTitle(general.getName())

                                .setMessage(general.getDetails())

                                .setPositiveButton("返回", null);//直接关闭，没有响应事件

                            AlertDialog dialog = builder.create();

                            dialog.show();

                        }

                    });

                    AlertDialog dialog = builder.create();

                    dialog.show();

                return true;

            }

        });

    }

    private void initView() {

        mlvGeneral=(ListView) findViewById(R.id.lvGeneral);

        mAdapter=new GeneralAdapter(mGenerals, this);

        mlvGeneral.setAdapter(mAdapter);

    }

    private void initData() {

        String[] names=getResources().getStringArray(R.array.general);

        String[] details=getResources().getStringArray(R.array.details);

        int[] resid={

                R.drawable.baiqi,R.drawable.caocao,R.drawable.chengjisihan,

                R.drawable.hanxin,R.drawable.lishimin,R.drawable.nuerhachi,

                R.drawable.sunbin,R.drawable.sunwu,R.drawable.yuefei,

                R.drawable.zhuyuanzhang

            };

        mGenerals=new ArrayList<GeneralBean>();

        for (int i = 0; i < resid.length; i++) {

            GeneralBean general=new GeneralBean(resid[i], names[i], details[i]);

            mGenerals.add(general);

        }

    }

    class GeneralAdapter extends BaseAdapter{

        List<GeneralBean> generals;

        MainActivity context;

        public void remove(int position){//适配器移出方法，就是移除资源总数据，

            generals.remove(position);

            notifyDataSetChanged();//BaseAdapter的方法，执行后安卓系统会调用getView()方法重新绘制，

        }

        public void add(GeneralBean general){

            mGenerals.add(general);

            notifyDataSetChanged();

        }

        public void update(int position,GeneralBean general){

            mGenerals.set(position, general);

            notifyDataSetChanged();

        }

        public GeneralAdapter(List<GeneralBean> generals, MainActivity context) {

            super();

            this.generals = generals;

            this.context = context;

        }

        @Override

        public int getCount() {

            return generals.size();

        }

        @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;

        }

        @Override

        public View getView(int position, View convertView, ViewGroup parent) {

            ViewHolder holder=null;

            if(convertView==null){

                convertView=View.inflate(context, R.layout.item_general, null);

                holder=new ViewHolder();

                holder.ivThumb=(ImageView) convertView.findViewById(R.id.ivThumb);

                holder.tvName=(TextView) convertView.findViewById(R.id.tvName);

                convertView.setTag(holder);

            }else{//滚屏的时候重复利用convertView

                holder=(ViewHolder) convertView.getTag();

            }

            GeneralBean general=generals.get(position);

            holder.ivThumb.setImageResource(general.getResid());

            holder.tvName.setText(general.getName());

            return convertView;

        }

        class ViewHolder{

            ImageView ivThumb;

            TextView tvName;

        }

    }

    @Override

    //处理UpdateActivity返回的结果

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {

        super.onActivityResult(requestCode, resultCode, data);

        if(resultCode!=RESULT_OK){//判断resultCode

            return ;

        }

        switch (requestCode) {//判断requestCode

        case ACTION_UPDATE:

            GeneralBean general=(GeneralBean) data.getSerializableExtra("general");//获取修改完以后的对象

            mAdapter.update(mPosition, general);//调用适配器的更新方法，mPosition是修改的对象在集合的索引

            break;

        case ACTION_ADD:

            break;

        }

    }

}

mainactivity页面：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"

    android:layout_height="match_parent" >

    <ListView

        android:id="@+id/lvGeneral"

        android:layout_width="match_parent"

        android:layout_height="match_parent"/>

</RelativeLayout>

修改Activity：

package com.sxt.day05_11;

import android.app.Activity;

import android.content.Intent;

import android.os.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.EditText;

import android.widget.ImageView;

import com.sxt.day05_11.entity.GeneralBean;

public class UpdateActivity extends Activity {

    //要修改对象的名字（控件显示），详细信息（控件显示），

    EditText metName,metDetails;

    ImageView mivThumb;//图片

    int mPhotoId;//图片id

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_update);

        initView();

        initData();

        setListener();

    }

    private void setListener() {

        setOKClickListtener();

        setCancelClickListener();

    }

    private void setCancelClickListener() {

        findViewById(R.id.btnCancel).setOnClickListener(new OnClickListener() {

            @Override

            public void onClick(View v) {

                finish();

            }

        });

    }

    private void setOKClickListtener() {

        findViewById(R.id.btnOK).setOnClickListener(new OnClickListener() {

            @Override

            public void onClick(View v) {

                String details=metDetails.getText().toString();

                String name=metName.getText().toString();

                //不能根据图片控件获取图片的id，所以多用一个变量保存图片的id

                GeneralBean general=new GeneralBean(mPhotoId, name, details);

                Intent intent=new Intent(UpdateActivity.this, MainActivity.class);

                intent.putExtra("general", general);

                setResult(RESULT_OK, intent);//RESULT_OK是resultCode结果码

                finish();//关闭当前页面

            }

        });

    }

    //接收数据

    private void initData() {

        Intent intent = getIntent();

        GeneralBean general=(GeneralBean) intent.getSerializableExtra("general");

        //数据显示在控件里面

        metDetails.setText(general.getDetails());

        metName.setText(general.getName());

        mivThumb.setImageResource(general.getResid());//图片是根据id获取的

        mPhotoId=general.getResid();//保存图片id

    }

    private void initView() {

        //用布局实例化对象

        metDetails=(EditText) findViewById(R.id.etDetails);

        metName=(EditText) findViewById(R.id.etName);

        mivThumb=(ImageView) findViewById(R.id.iv_updae_thumb);

    }

}

修改Activity页面：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"

    android:layout_height="match_parent">

    <ImageView

        android:id="@+id/iv_updae_thumb"

        android:layout_width="80dp"

        android:layout_height="80dp"

        android:scaleType="fitXY"

        android:src="@drawable/baiqi"/>

    <EditText                                           可编辑的输入框

        android:id="@+id/etName"

        android:layout_below="@id/iv_updae_thumb"

        android:layout_width="80dp"

        android:layout_height="wrap_content"

        android:text="白起"/>

    <EditText

        android:id="@+id/etDetails"

        android:layout_width="match_parent"

        android:layout_height="110dp"

        android:text="@string/detail"

        android:layout_toRightOf="@id/iv_updae_thumb"/>

    <Button

        android:id="@+id/btnOK"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="修改"

        android:layout_below="@id/etDetails"

        android:layout_marginLeft="50dp"

        android:layout_marginTop="20dp"/>

    <Button

        android:id="@+id/btnCancel"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="放弃"

        android:layout_below="@id/etDetails"

        android:layout_marginTop="20dp"

        android:layout_toRightOf="@id/btnOK"

        android:layout_marginLeft="50dp"/>

</RelativeLayout>

item_general.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="horizontal" >         横向

    <ImageView

        android:id="@+id/ivThumb"

        android:layout_width="60dp"

        android:layout_height="60dp"

        android:scaleType="fitXY"                  自动缩放

        android:src="@drawable/baiqi"/>

    <TextView

        android:id="@+id/tvName"

        android:layout_width="wrap_content"

        android:layout_height="60dp"

        android:gravity="center_vertical"        内部垂直居中

        android:textSize="20sp"

        android:text="白起"

        android:layout_marginLeft="10dp"/>

</LinearLayout>