Android实现用户登录和注册界面

       我们在做android项目时经常会用到用户登录，这里呈上实现了Spinner的登录界面，初学的朋友可以直接拿过来使用。本界面使用的是流式布局，也是我最喜欢用的布局方式，同学们可以通过代码了解一下。代码中Intent的使用有点杂乱，主要是为了实现界面2选择完地址后，界面1已结填写的类容随着Activity来回传递，避免丢失。如果同学们有更好的实现方法就把那些Intent删除。

主界面MainActivity

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    private Spinner spinner;
    private ArrayAdapter adapterspin;
    String spinnertext;
    TextView textView;
    Button btn;
    EditText ed1,ed2,ed3;

    private static final String[] m={"汉族","回族","藏族","壮族","朝鲜族","维吾尔族"};
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        init();
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, cs.class);
                intent.putExtra("ed1",ed1.getText().toString() );
                intent.putExtra("ed2",ed2.getText().toString() );
                intent.putExtra("ed3",ed3.getText().toString() );
                startActivity(intent);
            }
        });
        Intent intent =getIntent();
            String dz = intent.getStringExtra("dz");
            String user = intent.getStringExtra("ed1");
            String password = intent.getStringExtra("ed2");
            String rpassword = intent.getStringExtra("ed3");
                ed1.setText(user);
                ed2.setText(password);
                ed3.setText(rpassword);
            textView.setText(dz);


    }
    public void init(){
        spinner=findViewById(R.id.spinner1);
        spinner.setOnItemSelectedListener(new SpinnerSelectedListener());
        adapterspin = new ArrayAdapter(this,android.R.layout.simple_spinner_item,m);
        adapterspin.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner.setAdapter(adapterspin);
        spinner.setOnItemSelectedListener(new SpinnerSelectedListener());
        spinner.setVisibility(View.VISIBLE);
        btn=findViewById(R.id.button);
        textView=findViewById(R.id.textView10);
        ed1=findViewById(R.id.ed1);
        ed2=findViewById(R.id.ed2);
        ed3=findViewById(R.id.ed3);
    }
    class SpinnerSelectedListener implements AdapterView.OnItemSelectedListener {

        public void onItemSelected(AdapterView arg0, View arg1, int arg2,
                                   long arg3) {

            spinnertext=m[arg2];

        }

        public void onNothingSelected(AdapterView arg0) {
        }
    }
}

Spinner地址选择界面cs.java

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.List;

public class cs extends AppCompatActivity {

    private ListView listView;
    private List mList = new ArrayList<>();
    private List mclist = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_cs);
        initList();
        Intent intent = getIntent();
        String ed1=intent.getStringExtra("ed1");
        String ed2=intent.getStringExtra("ed2");
        String ed3=intent.getStringExtra("ed3");
        mclist.add(ed1);
        mclist.add(ed2);
        mclist.add(ed3);
        this.listView = (ListView) findViewById(R.id.listView);

        final MyAdapter adapter = new MyAdapter(cs.this, mList,mclist);
        listView.setAdapter(adapter);
        //ListView item的点击事件
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView adapterView, View view, int i, long l) {

            }
        });
        //ListView item 中的删除按钮的点击事件
        adapter.setOnItemDeleteClickListener(new MyAdapter.onItemDeleteListener() {
            @Override
            public void onDeleteClick(int i) {

            }
        });
    }

    
    private void initList() {

        mList.add("北京");
        mList.add("上海");
        mList.add("深圳");
        mList.add("杭州");
        mList.add("广州");
        mList.add("杭州");

    }
}

适配器MyAdapter.java

import android.content.Context;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;

public class MyAdapter extends BaseAdapter {
    private Context mContext;
    private List mList = new ArrayList<>();
    private List mclist = new ArrayList<>();

    public MyAdapter(Context context, List list, List clist) {
        mContext = context;
        mList = list;
        mclist=clist;
    }

    @Override
    public int getCount() {
        return mList.size();
    }

    @Override
    public Object getItem(int i) {
        return mList.get(i);
    }

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

    @Override
    public View getView(final int i, View view, ViewGroup viewGroup) {
        ViewHolder viewHolder = null;
        if (view == null) {
            viewHolder = new ViewHolder();
            view = LayoutInflater.from(mContext).inflate(R.layout.list_item, null);
            viewHolder.mTextView = (TextView) view.findViewById(R.id.item_tv);
            viewHolder.mButton =  view.findViewById(R.id.item_btn);
            view.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) view.getTag();
        }
        viewHolder.mTextView.setText(mList.get(i));
        viewHolder.mButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(mContext, MainActivity.class);
                intent.putExtra("dz",mList.get(i) );
                intent.putExtra("ed1",mclist.get(0) );
                intent.putExtra("ed2",mclist.get(1) );
                intent.putExtra("ed3",mclist.get(2) );
                mContext.startActivity(intent);
            }
        });
        return view;
    }

    
    public interface onItemDeleteListener {
        void onDeleteClick(int i);
    }

    private onItemDeleteListener mOnItemDeleteListener;

    public void setOnItemDeleteClickListener(onItemDeleteListener mOnItemDeleteListener) {
        this.mOnItemDeleteListener = mOnItemDeleteListener;
    }

    class ViewHolder {
        TextView mTextView;
        Button mButton;
    }

}

对应的XML文件

activity_main.xml

activity_cs.xml

list_item.xml

结束。

后面同学们可以在MainActivity里添加按键的监听实现自己想要的功能了！其他一些改动可以自己完成。