HorizontalScrollView組合RadioGroup,實現點選RadioButton時自動滾動
阿新 • • 發佈：2019-02-08
做開發時用到這個小應用:點選RadioButton時自動滑動到螢幕的中央,java程式碼如下
[mw_shl_code=java,true]
public class ScrollTextActivity extends Activity {
HorizontalScrollView scrollView;
RadioGroup radio_group;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
scrollView = (HorizontalScrollView) findViewById(R.id.scrollview);
radio_group = (RadioGroup) findViewById(R.id.radio_group);
//幕
Display d = getWindowManager().getDefaultDisplay();
DisplayMetrics dm = new DisplayMetrics();
d.getMetrics(dm);
final int screenHalf = d.getWidth()/2;//螢幕寬度的一半
radio_group.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener(){
@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
int scrollX = scrollView.getScrollX();
System.out.println("scrollX----->"+scrollX);
RadioButton rb = (RadioButton) findViewById(checkedId);
int left = rb.getLeft();
int leftScreen = left-scrollX;
scrollView.smoothScrollBy((leftScreen-screenHalf), 0);
}});
}
}[/mw_shl_code]
佈局檔案main_activity.xml
[mw_shl_code=html,true]<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<HorizontalScrollView
android:id="@+id/scrollview"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<RadioGroup
android:gravity="center_vertical"
android:id="@+id/radio_group"
android:layout_width="fill_parent"
android:layout_height="80dip"
android:orientation="horizontal" >
<RadioButton
android:id="@+id/button1"
android:text="@string/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<RadioButton
android:layout_marginLeft="30dip"
android:id="@+id/button2"
android:text="@string/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<RadioButton
android:layout_marginLeft="30dip"
android:id="@+id/button3"
android:text="@string/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<RadioButton
android:layout_marginLeft="30dip"
android:id="@+id/button4"
android:text="@string/button4"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<RadioButton
android:layout_marginLeft="30dip"
android:id="@+id/button5"
android:text="@string/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RadioGroup>
</HorizontalScrollView>
</LinearLayout>[/mw_shl_code]
[mw_shl_code=java,true]
public class ScrollTextActivity extends Activity {
HorizontalScrollView scrollView;
RadioGroup radio_group;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
scrollView = (HorizontalScrollView) findViewById(R.id.scrollview);
radio_group = (RadioGroup) findViewById(R.id.radio_group);
//幕
Display d = getWindowManager().getDefaultDisplay();
DisplayMetrics dm = new DisplayMetrics();
d.getMetrics(dm);
final int screenHalf = d.getWidth()/2;//螢幕寬度的一半
radio_group.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener(){
@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
int scrollX = scrollView.getScrollX();
System.out.println("scrollX----->"+scrollX);
RadioButton rb = (RadioButton) findViewById(checkedId);
int left = rb.getLeft();
int leftScreen = left-scrollX;
scrollView.smoothScrollBy((leftScreen-screenHalf), 0);
}});
}
}[/mw_shl_code]
佈局檔案main_activity.xml
[mw_shl_code=html,true]<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<HorizontalScrollView
android:id="@+id/scrollview"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<RadioGroup
android:gravity="center_vertical"
android:id="@+id/radio_group"
android:layout_width="fill_parent"
android:layout_height="80dip"
android:orientation="horizontal" >
<RadioButton
android:id="@+id/button1"
android:text="@string/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<RadioButton
android:layout_marginLeft="30dip"
android:id="@+id/button2"
android:text="@string/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<RadioButton
android:layout_marginLeft="30dip"
android:id="@+id/button3"
android:text="@string/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<RadioButton
android:layout_marginLeft="30dip"
android:id="@+id/button4"
android:text="@string/button4"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<RadioButton
android:layout_marginLeft="30dip"
android:id="@+id/button5"
android:text="@string/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RadioGroup>
</HorizontalScrollView>
</LinearLayout>[/mw_shl_code]