作业一，界面设计的代码：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
     android:layout_height="match_parent"
    android:layout_width="match_parent">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Please choose a flowe you like!"
        android:singleLine="true"
        android:ellipsize="marquee"
        android:marqueeRepeatLimit="marquee_forever"
        android:focusable="true"
        android:focusableInTouchMode="true"
        android:textSize="50dp"
        />

    <ImageView
        android:layout_width="317dp"
        android:layout_height="238dp"
        android:layout_gravity="center"
        android:id="@+id/hua"
        />
    <RadioGroup
        android:id="@+id/g1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:layout_gravity="center_horizontal">
        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="梅花        "
            android:textSize="20dp"
            android:id="@+id/meihua" />
        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="石榴花       "
            android:textSize="20dp"
            android:id="@+id/shiliuhua" />
        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="象牙花"
            android:textSize="20dp"
            android:id="@+id/xiangyahua" />

    </RadioGroup>
    <RadioGroup
        android:id="@+id/g2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:layout_gravity="center_horizontal">
        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="绣球花    "
            android:textSize="20dp"
            android:id="@+id/xiuqiuihua" />
        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="玉兰花       "
            android:textSize="20dp"
            android:id="@+id/yulanhua" />
        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="牡丹花"
            android:textSize="20dp"
            android:id="@+id/nudanhua"/>

    </RadioGroup>

</LinearLayout>

package com.example.woshishen.xuanhuaapplication;

import android.media.Image;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.RadioButton;
import android.widget.RadioGroup;

public class MainActivity extends AppCompatActivity {
    private ImageView H;
    private RadioButton MH;
    private RadioButton SLH;
    private RadioButton XYH;
    private RadioButton XQH;
    private RadioButton YLH;
    private RadioButton MDH;
    private RadioGroup G1;
    private RadioGroup G2;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        H = (ImageView) findViewById(R.id.hua);
        MH = (RadioButton) findViewById(R.id.meihua);
        SLH = (RadioButton) findViewById(R.id.shiliuhua);
        XYH = (RadioButton) findViewById(R.id.xiangyahua);
        XQH = (RadioButton) findViewById(R.id.xiuqiuihua);
        YLH = (RadioButton) findViewById(R.id.yulanhua);
        MDH = (RadioButton) findViewById(R.id.nudanhua);
        G1 = (RadioGroup) findViewById(R.id.g1);
        G2 = (RadioGroup) findViewById(R.id.g2);

        G1.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup radioGroup, int i) {
                if (MH.isChecked()) {
                    H.setImageResource(R.drawable.meihua);
                   G2.clearCheck();
                }
                if (SLH.isChecked()) {
                    H.setImageResource(R.drawable.shiliu);
                    G2.clearCheck();
                }
                if (XYH.isChecked()) {
                    H.setImageResource(R.drawable.xiangya);
                    G2.clearCheck();
                }

            }
        });
        G2.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup radioGroup, int i) {
                if (XQH.isChecked()) {
                    H.setImageResource(R.drawable.xiuqiu);
                    G1.clearCheck();
                }
                if (YLH.isChecked()) {
                    H.setImageResource(R.drawable.yulan);
                    G1.clearCheck();
                }
                if (MDH.isChecked()) {
                    H.setImageResource(R.drawable.mudan);
                    G1.clearCheck();
                }

            }
        });

    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.woshishen.tupianapplication.MainActivity">

    <ImageView
        android:layout_width="104dp"
        android:layout_height="96dp"
        android:layout_gravity="center"
        android:src="http://www.mamicode.com/@drawable/tupian"
        android:id="@+id/imageView" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="退出"
        android:id="@+id/tuichu"/>
</LinearLayout>

package com.example.woshishen.tupianapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;


public class MainActivity extends AppCompatActivity {
    private ImageView TP;
    private Button TC;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TP = (ImageView) findViewById(R.id.imageView);
        TC = (Button) findViewById(R.id.tuichu);

        TC.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(MainActivity.this, "再按一次退出按钮", Toast.LENGTH_LONG).show();
                TC.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        MainActivity.this.finish();
                    }
                });
            }
        });

    }
    @Override
    public boolean onTouchEvent (MotionEvent event){

        if (event.getAction() == MotionEvent.ACTION_MOVE) {
            float x = event.getX();
            float y = event.getY();
            String la = "X坐标：" + x + ",Y坐标" + y;
            TP.setX(x - 150);
            TP.setY(y - 300);
            Toast.makeText(this,la,Toast.LENGTH_LONG).show();
        }
        return super.onTouchEvent(event);


    }
}