我有一个简单的滑动页面示例,只有三页。
“黄色按钮”、“蓝色按钮”、“红色按钮”三个页面各有一个按钮。
我想将“黄色按钮”等按钮的名称更改为“+”,我该怎么做?
我尝试在“onClickYellowButton”方法中进行更改,但直到用户按下一个键并且我想在显示页面后立即更改。
谢谢你的帮助。
自定义viewpager
public class CustomPagerAdapter extends PagerAdapter {
public Object instantiateItem(View collection, int position) {
LayoutInflater inflater = (LayoutInflater) collection.getContext()
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
int resId = 0;
switch (position) {
case 0: {
resId = R.layout.page_1;
break;
}
case 1: {
resId = R.layout.page_2;
break;
}
case 2: {
resId = R.layout.page_3;
break;
}
}
View view = inflater.inflate(resId, null);
((ViewPager) collection).addView(view, 0);
return view;
}
@Override
public void destroyItem(View arg0, int arg1, Object arg2) {
((ViewPager) arg0).removeView((View) arg2);
}
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == ((View) arg1);
}
@Override
public Parcelable saveState() {
return null;
}
@Override
public int getCount() {
return 3;
}
}
主要活动
public class MainActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Create and set adapter
CustomPagerAdapter adapter = new CustomPagerAdapter();
ViewPager myPager = (ViewPager) findViewById(R.id.customviewpager);
myPager.setAdapter(adapter);
myPager.setCurrentItem(1);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
/**
* Click button on blue page
*/
public void onClickBlueButton(View v) {
Toast.makeText(getApplicationContext(), "Blue screen", Toast.LENGTH_SHORT).show();
}
/**
* Click button on yellow page
*/
public void onClickYellowButton(View v) {
Button b=(Button) findViewById(R.id.buttonYellow);
b.setText("+");
Toast.makeText(getApplicationContext(), "Yellow screen", Toast.LENGTH_SHORT).show();
}
/**
* Click button on red page
*/
public void onClickRedButton(View v) {
Toast.makeText(getApplicationContext(), "Red screen", Toast.LENGTH_SHORT).show();
}
}
主要的 xml
<?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" >
<android.support.v4.view.ViewPager
android:id="@+id/customviewpager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
第 1 页
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/blue"
android:orientation="vertical" >
<Button
android:id="@+id/buttonBlue"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@string/label_blue"
android:onClick="@string/listenerBlueButton" />
</LinearLayout>
第2页
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/yellow"
android:orientation="vertical" >
<Button
android:id="@+id/buttonYellow"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@string/label_yellow"
android:onClick="@string/listenerYellowButton" />
</LinearLayout>
第 3 页
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/red"
android:orientation="vertical" >
<Button
android:id="@+id/buttonRed"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@string/label_red"
android:onClick="@string/listenerRedButton" />
</LinearLayout>