我对其中显示的浏览器/不同布局感到有点绝望。
总结：切换不同的布局非常有效。现在我想在不同的布局上实现按钮/功能，这是不起作用的。
我有以下viewpager，它运行良好。它遍历布局列表并显示不同的布局。
我的活动
public static final String LOG_TAG = MainActivity.class.getSimpleName();
private ViewPager viewPager;
private ViewPagerAdapter viewPagerAdapter;
private LinearLayout dotsLayout;
private TextView[] dots;
private int[] layouts;
private Button btnSkip, btnNext;
@
Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_swipe);
viewPager = (ViewPager) findViewById(R.id.view_pager);
dotsLayout = (LinearLayout) findViewById(R.id.layoutDots);
//btnSkip = (Button) findViewById(R.id.btn_skip);
btnNext = (Button) findViewById(R.id.btn_next);
layouts = new int[] {
R.layout.activity_mmg_description_start,
R.layout.activity_mmg_question_1,
R.layout.activity_mmg_question_2,
R.layout.activity_mmg_question_3,
R.layout.activity_mmg_question_4,
R.layout.activity_mmg_question_5,
R.layout.activity_mmg_question_6,
R.layout.activity_mmg_question_7,
R.layout.activity_mmg_question_8,
R.layout.activity_mmg_question_9,
R.layout.activity_mmg_question_10,
R.layout.activity_mmg_question_11,
R.layout.activity_mmg_question_12,
R.layout.activity_mmg_question_13,
R.layout.activity_mmg_question_14
};
// adding bottom dots
addBottomDots(0);
viewPagerAdapter = new ViewPagerAdapter();
viewPager.setAdapter(viewPagerAdapter);
viewPager.addOnPageChangeListener(viewPagerPageChangeListener);
}
@
Override
public void onBackPressed() {}
public void btnNextClick(View v) {
// checking for last page
// if last page home screen will be launched
int current = getItem(1);
if (current < layouts.length) {
// move to next screen
viewPager.setCurrentItem(current);
} else {
launchHomeScreen();
}
}
ViewPager.OnPageChangeListener viewPagerPageChangeListener = new ViewPager.OnPageChangeListener() {
@
Override
public void onPageSelected(int position) {
addBottomDots(position);
// changing the next button text 'NEXT' / 'GOT IT'
if (position == layouts.length - 1) {
// last page. make button text to GOT IT
btnNext.setText(getString(R.string.start_measurement_manual));
//btnSkip.setVisibility(View.GONE);
} else {
// still pages are left
btnNext.setText(getString(R.string.next));
//btnSkip.setVisibility(View.VISIBLE);
}
}
@
Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
@
Override
public void onPageScrollStateChanged(int arg0) {
}
};
private void addBottomDots(int currentPage) {
dots = new TextView[layouts.length];
dotsLayout.removeAllViews();
for (int i = 0; i < dots.length; i++) {
dots[i] = new TextView(this);
dots[i].setText(Html.fromHtml("•"));
dots[i].setTextSize(35);
dots[i].setTextColor(getResources().getColor(R.color.dot_inactive));
dotsLayout.addView(dots[i]);
}
if (dots.length > 0)
dots[currentPage].setTextColor(getResources().getColor(R.color.dot_active));
}
private int getItem(int i) {
return viewPager.getCurrentItem() + i;
}
private void launchHomeScreen() {
startActivity(new Intent(this, ManualActivity.class));
finish();
}
public class ViewPagerAdapter extends PagerAdapter {
private LayoutInflater layoutInflater;
public ViewPagerAdapter() {
}
@
Override
public Object instantiateItem(ViewGroup container, int position) {
//Inflate the correct layout
layoutInflater = (LayoutInflater) getSystemServ**Option 1: starting with layout activity_mmg_question_1**ice(Context.LAYOUT_INFLATER_SERVICE);
//layouts[] is an int[] that points to resources such as R.layout.start_page
View inflatedView = layoutInflater.inflate(layouts[position], container, false);
((ViewPager) container).addView(inflatedView, 0);
switch (position) {
case R.layout.activity_mmg_description_start:
Log.d(LOG_TAG, "QD " + "Firstviewcame");
case R.layout.activity_mmg_question_1:
//LinearLayout linearLayout_mmg_1 = (LinearLayout)inflatedView.findViewById(R.id.linearlayout_mmg_1);
Button testButton = (Button) findViewById(R.id.testbutton);
testButton.setOnClickListener(new View.OnClickListener() {
@
Override
public void onClick(View v) {
Log.d(LOG_TAG, "QD " + "Swipebuttonclicked");
}
});
}
return inflatedView;
}
@
Override
public int getCount() {
return layouts.length;
}
@
Override
public boolean isViewFromObject(View view, Object obj) {
return view == obj;
}
@
Override
public void destroyItem(ViewGroup container, int position, Object object) {
View view = (View) object;
container.removeView(view);
}
}
我想为不同的布局添加功能。在布局上：activity_mmg_question_1是一个按钮（R.id.testbutton），它应该写一条日志消息。
我尝试了一些选择。
选项1：从布局activity_mmg_question_1
开始在开头取消注释R.layout.activity_mmg_description_start：
layouts = new int[]{
//R.layout.activity_mmg_description_start,
R.layout.activity_mmg_question_1,
以下代码有效：
@Override
public Object instantiateItem(ViewGroup container, int position) {
//Inflate the correct layout
layoutInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
//layouts[] is an int[] that points to resources such as R.layout.start_page
View inflatedView = layoutInflater.inflate(layouts[position], container, false);
((ViewPager)container).addView(inflatedView,0);
LinearLayout linearLayout_mmg_1 = (LinearLayout)inflatedView.findViewById(R.id.linearlayout_mmg_1);
Button testButton = (Button)findViewById(R.id.testbutton);
testButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.d (LOG_TAG, "QD " + "Swipebuttonclicked");
}
});
return inflatedView;
}
完全可以理解：它使布局膨胀，找到按钮，起作用。
选项2：从布局activity_mmg_description_start开始
从开头的R.layout.activity_mmg_description_start开始：
layouts = new int[]{
R.layout.activity_mmg_description_start,
R.layout.activity_mmg_question_1,
最终以
结束FATAL EXCEPTION: main
[...]
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
我想我也得到了这个：在第一个布局（R.layout.activity_mmg_description_start）上它没有找到按钮，因此它指向null，并显示错误。
如何防止这种情况？这让我想到了：
选项3：开关案例
显示不同的布局有效，但按钮的日志消息不起作用。
@Override
public Object instantiateItem(ViewGroup container, int position) {
//Inflate the correct layout
layoutInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
//layouts[] is an int[] that points to resources such as R.layout.start_page
View inflatedView = layoutInflater.inflate(layouts[position], container, false);
((ViewPager)container).addView(inflatedView,0);
switch (position){
case R.layout.activity_mmg_description_start:
Log.d (LOG_TAG, "QD " + "Firstviewcame");
case R.layout.activity_mmg_question_1:
//LinearLayout linearLayout_mmg_1 = (LinearLayout)inflatedView.findViewById(R.id.linearlayout_mmg_1);
Button testButton = (Button)findViewById(R.id.testbutton);
testButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.d (LOG_TAG, "QD " + "Swipebuttonclicked");
}
});
}
return inflatedView;
}
有人有想法或解决方案吗？
最好并提前致谢，
tigercode
答案 0 :(得分：1)
我认为你应该使用Fragments。
在调用（（ViewPager）容器）之前尝试setOnClickListener .addView（inflatedView，0）;
public Object instantiateItem(ViewGroup container, int position) {
//Inflate the correct layout
layoutInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
//layouts[] is an int[] that points to resources such as R.layout.start_page
View inflatedView = layoutInflater.inflate(layouts[position], container, false);
switch (position){
case R.layout.activity_mmg_description_start:
Log.d (LOG_TAG, "QD " + "Firstviewcame");
case R.layout.activity_mmg_question_1:
//LinearLayout linearLayout_mmg_1 = (LinearLayout)inflatedView.findViewById(R.id.linearlayout_mmg_1);
Button testButton = (Button)findViewById(R.id.testbutton);
testButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.d (LOG_TAG, "QD " + "Swipebuttonclicked");
}
});
}
((ViewPager)container).addView(inflatedView,0);
return inflatedView;
}