第四周安卓作业

任务一

1、图片选择器之跑马灯

<?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_flower"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    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"
    tools:context="com.example.flower.flowerActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="@android:color/holo_red_dark"
        android:layout_gravity="center"
        android:scrollHorizontally="true"
    android:scrollbars="horizontal"
    android:text="请选择你喜欢的小花花"
        android:singleLine="true"
        android:ellipsize="marquee"
        android:focusableInTouchMode="true"
        android:focusable="true"
        android:marqueeRepeatLimit="marquee_forever"
    android:textSize="90sp"
    android:id="@+id/biaoti"   />
以上内容通过百度搜索安卓横向跑马灯
遇到的问题：标题不滚动 后来发现是字体太小了==
2、按钮

<ImageView
android:layout_marginTop="30dp"
android:layout_width="200dp"
android:layout_height="140dp"
android:layout_gravity="center"
android:id="@+id/iv_tupian"/>

    <RadioGroup
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:orientation="vertical"
        android:id="@+id/hualei"
        >

    <RadioGroup
        android:layout_marginTop="40dp"
        android:id="@+id/rg_rg1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:orientation="horizontal"
        >
    <RadioButton
        android:id="@+id/rbt_mei"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="20sp"
        android:layout_marginRight="@dimen/activity_vertical_margin"
        android:checked="true"
        android:text="梅花"/>
    <RadioButton
        android:id="@+id/rbt_shinan"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="20sp"
        android:text="石楠花"/>
        <RadioButton
            android:id="@+id/rbt_xiangya"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="20sp"
            android:text="象牙花"/>
    </RadioGroup>
        <RadioGroup
        android:layout_marginTop="40dp"
        android:id="@+id/rg_rg2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:orientation="horizontal"
        >
        <RadioButton
            android:id="@+id/rbt_xiuqiu"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="20sp"
            android:text="绣球花"/>
        <RadioButton
            android:id="@+id/rbt_yulan"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="20sp"
            android:text="玉兰花"/>
        <RadioButton
            android:id="@+id/rbt_mudan"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="20sp"
            android:text="牡丹花"/>
    </RadioGroup>
</RadioGroup>

</LinearLayout>
以上是添加按钮
java部分

package com.example.flower;

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

public class flowerActivity extends AppCompatActivity {
    private TextView biaoti;
   private ImageView iv_tupian;
    private RadioGroup rg_rg1;
    private RadioGroup hualei;
    private RadioButton rbt_mei;
    private  RadioButton rbt_shinan;
    private  RadioButton rbt_xiangya;
    private  RadioGroup  rg_rg2;
    private RadioButton rbt_xiuqiu;
    private  RadioButton rbt_yulan;
    private  RadioButton rbt_mudan;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_flower);
        biaoti = (TextView) findViewById(R.id.biaoti);
        rbt_mei = (RadioButton) findViewById(R.id.rbt_mei);
        rbt_shinan = (RadioButton) findViewById(R.id.rbt_shinan);
        rbt_xiangya = (RadioButton) findViewById(R.id.rbt_xiangya);
        rbt_xiuqiu = (RadioButton) findViewById(R.id.rbt_xiuqiu);
        rbt_yulan = (RadioButton) findViewById(R.id.rbt_yulan);
        rbt_mudan = (RadioButton) findViewById(R.id.rbt_mudan);
        rg_rg1 = (RadioGroup) findViewById(R.id.rg_rg1);
        rg_rg2 = (RadioGroup) findViewById(R.id.rg_rg2);
        hualei = (RadioGroup) findViewById(R.id.hualei);
        iv_tupian=(ImageView)findViewById(R.id.iv_tupian);
建立响应事件

 rg_rg1.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup radioGroup, int i) {
                if(rbt_mei.isChecked()){
                    iv_tupian.setImageResource(R.mipmap.mei);
                    rg_rg2.clearCheck();
                }
                if(rbt_shinan.isChecked()){
                    iv_tupian.setImageResource(R.mipmap.shinan);
                    rg_rg2.clearCheck();
                }
                if(rbt_xiangya.isChecked()){
                    iv_tupian.setImageResource(R.mipmap.xiangya);
                    rg_rg2.clearCheck();
                }

            }
        });
       rg_rg2.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup radioGroup, int i) {
                if(rbt_xiuqiu.isChecked()){
                    iv_tupian.setImageResource(R.mipmap.xiuqiu);
                    rg_rg1.clearCheck();
                }
                if(rbt_yulan.isChecked()){
                    iv_tupian.setImageResource(R.mipmap.yulan);
                    rg_rg1.clearCheck();
                }
                if(rbt_mudan.isChecked()){
                    iv_tupian.setImageResource(R.mipmap.mudan);
                    rg_rg1.clearCheck();
                }

            }
        });

    }
}
用if语句解决非单选问题 因为发现有两个RadioGroup事件所以每一行都可以选择一种花类。在参考了部分资料之后选择用if语句如果rg1有选择时自动清除rg2的按钮选项 以此类推。
运行结果如下

任务二
xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main_xy"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    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.myapplication4.MainActivityXY">
    <ImageView
        android:layout_width="60dp"
        android:layout_height="60dp"
        android:layout_gravity="center_horizontal"
        android:id="@+id/iv_tupian" />

    <Button
        android:layout_marginTop="300dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:text="退出"
        android:id="@+id/bt_tuichu" />


</RelativeLayout>
以上是xml的内容
java

package com.example.myapplication4;

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

import static com.example.myapplication4.R.id.time;

public class MainActivityXY extends AppCompatActivity {
    private ImageView iv_tupian;
    private Button bt_tuichu;

    @Override
    protected void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main_xy);
    bt_tuichu = (Button) findViewById(R.id.bt_tuichu);
        iv_tupian = (ImageView) findViewById(R.id.iv_tupian);
        bt_tuichu.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (bt_tuichu.isClickable()) {
                    Toast.makeText(MainActivityXY.this, "再按一次退出按钮",
                            Toast.LENGTH_LONG).show();
                    bt_tuichu.setOnClickListener(new View.OnClickListener() {
                        @Override
                        public void onClick(View v) {
                            if (bt_tuichu.isClickable()) {
                                MainActivityXY.this.finish();
                            }
                        }
                    });
                }
            }
        });
    }

  
    public boolean onTouchEvent(MotionEvent event) {
        if (event.getAction() == MotionEvent.ACTION_MOVE) {
            float x = event.getX();
            float y = event.getY();
            String pos = "x坐标" + x + "y坐标" + y;
            Toast.makeText(this, pos, Toast.LENGTH_LONG).show();
            iv_tupian.setImageResource(R.mipmap.chu);
            iv_tupian.setX(x - 100);
            iv_tupian.setY(y - 150);
        }
        return super.onTouchEvent(event);
    }

   
    private long exitTime = 0;

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN) {
            if ((System.currentTimeMillis() - exitTime) > 2000) {
                Toast.makeText(getApplicationContext(), "再按一次退出程序", Toast.LENGTH_SHORT).show();
                exitTime = System.currentTimeMillis();
            } else {
                finish();
                System.exit(0);
            }
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }
}
成果如下