我知道如何使用 xml 布局开发选项卡活动，而且我知道如何在 android 中进行分页，如 android market 应用程序中所示
但我不知道如何将此分页概念与选项卡活动合并以及如何从 java 代码创建选项卡活动：
请参阅下面的代码，我使用线性布局进行分页：
示例.java
public class Sample extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// creates the Pagination Layout
PaginationLayout paginationLayout = new PaginationLayout(this);
paginationLayout.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
// creates content only for sample
TableLayout table = new TableLayout(this);
table.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
table.setGravity(Gravity.CENTER_HORIZONTAL|Gravity.CENTER_VERTICAL);
TableRow row = new TableRow(this);
row.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
table.addView(row);
TableRow row2 = new TableRow(this);
row2.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
table.addView(row2);
for(int i = 0; i< 50;i++){
Button button = new Button(this);
button.setText("Button " + i);
if (i%2==0) {
row.addView(button);
} else {
row2.addView(button);
}
}
// add the content in pagination
paginationLayout.addView(table);
// set pagination layout
setContentView(paginationLayout);
}
}
分页布局的代码是：
public class PaginationLayout extends LinearLayout {
private int mPageActive = 0;
private HorizontalScrollView mScroll;
private LinearLayout mBar;
public PaginationLayout(Context context) {
super(context);
setOrientation(LinearLayout.VERTICAL);
// creates the class that will control the gestures and apply it in the
// scroll
final GestureDetector mGestureDetector = new GestureDetector(new MySimpleOnGestureListener());
mScroll = new HorizontalScrollView(context);
mScroll.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
mScroll.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
if (mGestureDetector.onTouchEvent(event)) {
return true;
} else {
return false;
}
}
});
// creates Previous and Next buttons
Button btnPrevious = new Button(getContext());
btnPrevious.setLayoutParams(new LayoutParams(150, LayoutParams.FILL_PARENT));
btnPrevious.setText("Previous");
btnPrevious.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
previous();
}
});
Button btnMid = new Button(getContext());
btnMid.setLayoutParams(new LayoutParams(150, LayoutParams.FILL_PARENT));
btnMid.setText("Mid");
btnMid.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
next();
}
});
Button btnNext = new Button(getContext());
btnNext.setLayoutParams(new LayoutParams(150, LayoutParams.FILL_PARENT));
btnNext.setText("Next");
btnNext.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
next();
}
});
// bar that include the buttons
mBar = new LinearLayout(getContext());
mBar.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT));
mBar.setGravity(Gravity.CENTER_HORIZONTAL | Gravity.CENTER_VERTICAL);
mBar.setBackgroundColor(Color.GRAY);
mBar.addView(btnPrevious);
mBar.addView(btnNext);
//mBar.setBackgroundDrawable(getResources().getDrawable(R.drawable.android_1080p));
mBar.setVisibility(LinearLayout.INVISIBLE);
// add bar and scroll in the super (LinearLayout)
super.addView(mBar);
super.addView(mScroll);
}
/**
* All that the user include is added in the scroll
*/
@Override
public void addView(View child) {
mScroll.addView(child);
}
/**
* Controls if the top bar should appear or not
*/
@Override
protected void onSizeChanged(int arg0, int arg1, int arg2, int arg3) {
super.onSizeChanged(arg0, arg1, arg2, arg3);
View chield = mScroll.getChildAt(0);
if (chield != null) {
if (chield.getMeasuredWidth() > getWidth()) {
mBar.setVisibility(LinearLayout.VISIBLE);
} else {
mBar.setVisibility(LinearLayout.INVISIBLE);
}
}
}
/**
* does the effect "back a page"
*/
public void previous() {
mPageActive = (mPageActive > 0) ? mPageActive - 1 : 0;
mScroll.smoothScrollTo(mPageActive * mScroll.getWidth(), 0);
}
/**
* does the effect "forward a page"
*/
public void next() {
int pageWidth = mScroll.getWidth();
int nextPage = (mPageActive + 1) * pageWidth;
if (nextPage - mScroll.getScrollX() <= pageWidth) {
mScroll.smoothScrollTo(nextPage, 0);
mPageActive++;
} else {
mScroll.smoothScrollTo(mScroll.getScrollX(), 0);
}
}
/**
* Private class that controls the gestures, forward or back a page.
*/
private class MySimpleOnGestureListener extends SimpleOnGestureListener {
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
if (e1 != null && e2 != null) {
if (e1.getX() - e2.getX() > 0) {
// forward...
next();
return true;
} else if (e2.getX() - e1.getX() > 0) {
// back...
previous();
return true;
}
}
return false;
}
}
}
