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

<ImageViewandroid: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