带选择头像的用户注册界面

问题：

1）注意代码的位置，是不是在调用的时候相应的组件还没有被实例化
2）OnClickListener，按钮被点击时，是onClick方法被调用，方法外的代码不会被调用

代码：

MainActivity.java

package com.example.hello;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;

public class MainActivity extends Activity {

    final static int CODE = 0x11;

    private OnClickListener listener = new OnClickListener() {

        @Override
        public void onClick(View v) {
            Intent intent = new Intent(MainActivity.this, HeadActivity.class);
            startActivityForResult(intent, CODE);
        }
    };

    @Override
    public void onCreate(Bundle cx) {
        super.onCreate(cx);
        setContentView(R.layout.register);
        Button btn = (Button) findViewById(R.id.button1);
        btn.setOnClickListener(listener);

    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == CODE && resultCode == CODE) {
            Bundle bundle = data.getExtras();
            int imageId = bundle.getInt("imageId");
            ImageView iv = (ImageView) findViewById(R.id.imageView1);
            iv.setImageResource(imageId);
        }
    }

}

HeadActivity.java

package com.example.hello;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;

public class HeadActivity extends Activity {

    private int[] imageId = new int[] { R.drawable.cx1, R.drawable.cx2, R.drawable.cx3, R.drawable.cx4, R.drawable.cx5,
            R.drawable.cx6 };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.imagelist);
        GridView gridView = (GridView) findViewById(R.id.gridView);
        BaseAdapter adapter = new BaseAdapter() {

            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
                ImageView imageView;
                if (convertView == null) {
                    imageView = new ImageView(HeadActivity.this);
                    imageView.setAdjustViewBounds(true);
                    imageView.setMaxHeight(200);
                    imageView.setMaxWidth(200);
                    imageView.setPadding(5, 5, 5, 5);
                } else {
                    imageView = (ImageView) convertView;
                }
                imageView.setImageResource(imageId[position]);
                return imageView;
            }

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

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

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

        gridView.setAdapter(adapter);

        gridView.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Intent intent = getIntent();
                Bundle bundle = new Bundle();
                bundle.putInt("imageId", imageId[position]);
                intent.putExtras(bundle);
                setResult(0x11, intent);
                finish();
            }
        });
    }

}

imagelist.xml

<GridView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:padding="20dp"
    android:numColumns="4"
    android:verticalSpacing="5dp"
    android:horizontalSpacing="5dp"
    android:id="@+id/gridView"
     >

</GridView>

register.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:animateLayoutChanges="false"
    android:orientation="horizontal"
    android:padding="20dp" >

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:paddingTop="20dp" >

        <TableRow
            android:id="@+id/tableRow1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" >

            <TextView
                android:id="@+id/textView1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:text="用户名:" />

            <EditText
                android:id="@+id/editText1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:inputType="textPersonName"
                android:minWidth="150dp" >

                <requestFocus />
            </EditText>
        </TableRow>

        <TableRow
            android:id="@+id/tableRow2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" >

            <TextView
                android:id="@+id/textView2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:text="密码：" />

            <EditText
                android:id="@+id/editText2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:inputType="textPassword"
                android:minWidth="150dp" >
            </EditText>
        </TableRow>

        <TableRow
            android:id="@+id/tableRow3"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" >

            <TextView
                android:id="@+id/textView3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="确认密码：" />

            <EditText
                android:id="@+id/editText3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:inputType="textPassword"
                android:minWidth="150dp" >
            </EditText>
        </TableRow>
    </LinearLayout>

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:orientation="vertical" >

        <ImageView
            android:id="@+id/imageView1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/cx1" />

        <Button
            android:id="@+id/button1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="选择头像" />
    </LinearLayout>

</LinearLayout>