3.17作业

选择你喜欢的花

1. 布局设计代码

<TextViewandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_gravity="center"android:text="Please choose a flower you like!"android:textSize="40dp"android:ellipsize="marquee"android:marqueeRepeatLimit="marquee_forever"android:focusable="true"android:focusableInTouchMode="true"android:singleLine="true" />

首先设计了TextView，在经过网上查找以及自我思考后，给标题文字设了“跑马灯”的滚动状态，并且设置永远跑马灯；

标题文字要设置成单行显示也就是singleLine，以及文字要比TextView长；

要在文字上获得焦点；

      <ImageViewandroid:id="@+id/img_flower"android:layout_gravity="center_horizontal"android:layout_width="350dp"android:layout_height="200dp"android:layout_weight="0.33"/>

设置显示图片的框；

<LinearLayoutandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_gravity="center"><RadioGroupandroid:id="@+id/flower1"android:layout_width="wrap_content"android:layout_height="wrap_content"android:gravity="center"android:orientation="horizontal"><RadioButtonandroid:id="@+id/rbt_lihua"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="梨花    "android:textSize="25dp"/><RadioButtonandroid:id="@+id/rbt_meihua"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="梅花    "android:textSize="25dp" /><RadioButtonandroid:id="@+id/rbt_yinghua"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="樱花    "android:textSize="25dp" /></RadioGroup></LinearLayout>
<LinearLayoutandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_gravity="center"><RadioGroupandroid:id="@+id/flower2"android:layout_width="wrap_content"android:layout_height="wrap_content"android:gravity="center"android:orientation="horizontal"><RadioButtonandroid:id="@+id/rbt_shuixianhua"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="水仙花"android:textSize="25dp"/><RadioButtonandroid:id="@+id/rbt_youcaihua"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="油菜花"android:textSize="25dp" /><RadioButtonandroid:id="@+id/rbt_yulanhua"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="玉兰花"android:textSize="25dp" /></RadioGroup></LinearLayout>

设置六个按钮；

因为要两排三列所以我用了两个LinearLayout布局；

2.运行代码

public class MainActivity extends AppCompatActivity {
private ImageView img_flower;
private RadioGroup flower1;
private RadioGroup flower2;
private RadioButton rbt_lihua;
private RadioButton rbt_meihua;
private RadioButton rbt_yinghua;
private RadioButton rbt_youcaihua;
private RadioButton rbt_shuixianhua;
private RadioButton rbt_yulanhua;
@Override
protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);img_flower = (ImageView) findViewById(R.id.img_flower);flower1=(RadioGroup) findViewById(R.id.flower1);flower2=(RadioGroup) findViewById(R.id.flower2);rbt_lihua=(RadioButton) findViewById(R.id.rbt_lihua);rbt_meihua=(RadioButton) findViewById(R.id.rbt_meihua);rbt_yinghua=(RadioButton) findViewById(R.id.rbt_yinghua);rbt_youcaihua=(RadioButton) findViewById(R.id.rbt_youcaihua);rbt_shuixianhua=(RadioButton) findViewById(R.id.rbt_shuixianhua);rbt_yulanhua=(RadioButton) findViewById(R.id.rbt_yulanhua);

定义主键；

获取主键 findViewById；

    rbt_lihua.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View view) {if (rbt_lihua.isChecked()){img_flower.setImageResource(R.drawable.lihua);no1();}}});rbt_meihua.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View view) {if (rbt_meihua.isChecked()){img_flower.setImageResource(R.drawable.meihua);no1();}}});rbt_yinghua.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View view) {if (rbt_yinghua.isChecked()){img_flower.setImageResource(R.drawable.yinghua);no1();}}});rbt_shuixianhua.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View view) {if (rbt_shuixianhua.isChecked()){img_flower.setImageResource(R.drawable.shuixianhua);no2();}}});rbt_youcaihua.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View view) {if (rbt_youcaihua.isChecked()){img_flower.setImageResource(R.drawable.youcaihua);no2();}}});rbt_yulanhua.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View view) {if (rbt_yulanhua.isChecked()){img_flower.setImageResource(R.drawable.yulanhua);no2();}}});}

设置监听按钮；

通过RadioButton的选中状态获取

void no1(){rbt_shuixianhua.setChecked(false);rbt_youcaihua.setChecked(false);rbt_yulanhua.setChecked(false);
}
void no2(){rbt_meihua.setChecked(false);rbt_lihua.setChecked(false);rbt_yinghua.setChecked(false);
}
}

因为设置了两组RadioGroup，所以，当点第一组的RadioButton时第二组也能被选上，所以这里要设置无返回值类型，同时上面也要调用这个方法；

坐标信息

1.布局设计代码

    <ImageViewandroid:id="@+id/img"android:layout_width="wrap_content"android:layout_height="wrap_content"android:src="@drawable/b"/>

很简单的布局代码，只需要插入一张图就好了

2.运行代码

public class MainActivity extends AppCompatActivity {
private ImageView img;
private long time;
@Override
protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);
img = (ImageView) findViewById(R.id.img);
}@Override
public boolean onTouchEvent(MotionEvent event) {if (event.getAction()==MotionEvent.ACTION_DOWN){String pos= "";float x= event.getX();float y =event.getY();img.setPadding((int)x-50,(int)y-300,0,0);pos="x轴坐标"+x+"y轴坐标"+y;Toast.makeText(this,pos,Toast.LENGTH_SHORT).show();}return super.onTouchEvent(event);
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {if(event.getKeyCode()==KeyEvent.KEYCODE_BACK){exit();return false;}return super.onKeyDown(keyCode, event);
}void exit(){if(System.currentTimeMillis()-time>2000){Toast.makeText(this,"再点一次退出程序!",Toast.LENGTH_SHORT).show();time=System.currentTimeMillis();}else {finish();}
}
}

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