（二）用户交互
2.1ActionBar
1.首先，调用onCreateOptionsMenu(Menu menu)方法为actionbar设置样式
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.support,menu);
return true;
}
res/menu/support.xml如下
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<item
android:id="@+id/action_delete"
android:icon="@android:drawable/ic_menu_delete"
app:showAsAction="ifRoom"
android:title="delete" />
<item
android:id="@+id/action_setting"
android:showAsAction="never"
android:orderInCategory="100"
android:title="action_setting" />
</menu>
接着，若Activity继承自AppCompatActivity，则调用代码
android.support.v7.app.ActionBar actionBar=getSupportActionBar();
否则直接调用
ActionBar actionBar=getActionBar();
2.2ToolBar
如今Google官方推荐使用Toolbar替代ActionBar
1.首先在XML中定义资源，要注意主题颜色，因为Toolbar默认不会自动继承当前material design的风格
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/colorAccent"
app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">
接着在代码中将toolbar集成
Toolbar toolbar= (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
2.3动态方向锁定
1.通过setRequestedOrientation()方法实现，首先设置一个tooglebutton来设置是否锁定
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_orientation);
toggleButton = (ToggleButton) findViewById(R.id.tb_orientation);
assert toggleButton != null;
if(getRequestedOrientation()!= ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED){
toggleButton.setChecked(true);
}else{
toggleButton.setChecked(false);
}
toggleButton.setOnCheckedChangeListener(this);
}
接着在监听器中对屏幕方向进行动态的设置
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
int current=getResources().getConfiguration().orientation;
if(isChecked){
switch (current){
case Configuration.ORIENTATION_LANDSCAPE:
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
break;
case Configuration.ORIENTATION_PORTRAIT:
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
break;
default:
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED);
}
}else{
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED);
}
}
2.5创建上下文动作
1.对于单个项相关上下文，使用PopupMenu
首先自定义ContextListItem类以封装PopupMenu
public class ContextListItem extends LinearLayout implements PopupMenu.OnMenuItemClickListener, View.OnClickListener {
private PopupMenu mPopupMenu;
private TextView mTextView;
public ContextListItem(Context context) {
this(context,null);
}
public ContextListItem(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public ContextListItem(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@Override
public boolean onMenuItemClick(MenuItem item) {
String string=mTextView.getText().toString();
switch (item.getItemId()){
case R.id.action_delete:
Toast.makeText(getContext(), "delete"+string,Toast.LENGTH_SHORT).show();
break;
case R.id.action_setting:
Toast.makeText(getContext(), "edit"+string,Toast.LENGTH_SHORT).show();
break;
}
return true;
}
@Override
protected void onFinishInflate() {
super.onFinishInflate();
mTextView= (TextView) findViewById(R.id.text);
View contextButton=findViewById(R.id.context);
contextButton.setOnClickListener(this);
mPopupMenu=new PopupMenu(getContext(),contextButton);
mPopupMenu.setOnMenuItemClickListener(this);
mPopupMenu.inflate(R.menu.support);
}
其中，list_item.xml如下
<?xml version="1.0" encoding="utf-8"?>
<com.vastsum.joshua.android50.day20160927.ContextListItem xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="?android:attr/listPreferredItemHeightSmall"
android:orientation="horizontal"
android:paddingLeft="?android:attr/listPreferredItemPaddingLeft"
android:paddingRight="?android:attr/listPreferredItemPaddingRight"
android:background="?android:attr/activatedBackgroundIndicator"
>
<TextView
android:id="@+id/text"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceListItemSmall"
android:layout_weight="1"
android:layout_gravity="center_vertical"/>
<ImageView
android:id="@+id/context"
style="@style/Widget.AppCompat.Light.ActionButton.Overflow"
android:layout_width="?android:attr/listPreferredItemHeightSmall"
android:layout_height="match_parent"
android:clickable="true"
android:focusable="false" />
</com.vastsum.joshua.android50.day20160927.ContextListItem>
2.如果会影响多个项，则可以启用ActionMode来响应用户动作，下面展示二者相结合的完整代码
public class ActionActivity extends AppCompatActivity implements AbsListView.MultiChoiceModeListener {
private static final String[] ITEMS = {"MOM", "DAD", "MOM", "DAD", "MOM", "DAD", "MOM", "DAD", "MOM", "DAD"};
private ListView mList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mList = new ListView(this);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, R.layout.list_item, R.id.text, ITEMS);
mList.setAdapter(adapter);
mList.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
mList.setMultiChoiceModeListener(this);
setContentView(mList, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
mList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
startActionMode(ActionActivity.this);
}
});
}
@Override
public void onItemCheckedStateChanged(ActionMode mode, int position, long id, boolean checked) {
int count = mList.getCheckedItemCount();
mode.setTitle(String.format("%d Select", count));
}
@Override
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
MenuInflater inflater = mode.getMenuInflater();
inflater.inflate(R.menu.support, menu);
return true;
}
@Override
public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
return true;
}
@Override
public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
return true;
}
@Override
public void onDestroyActionMode(ActionMode mode) {
}
}
2.8自定义BACK键
1.之前实现返回功能都是直接调用activity的finish()方法,现在发现可以调用
super.onBackPressed()
2.在默认情况下，UI中添加Fragment的操作不会再任务的回退栈中添加相应的Fragment,因此back键不能回退。
因此，首先要通过FragmentTransaction的addToBackStack()方法将fragment添加到回退栈
ft=getFragmentManager().beginTransaction();
ft.add(R.id.fl, MyFragment.newInstance("Second"));
ft.addToBackStack("Second");
ft.commit();
接着调用FragmentTransaction的popBackStack()方法将fragment弹出
public void back(View view) {
getFragmentManager().popBackStack();
}
顺便复习一下fragment的用法
public static class MyFragment extends Fragment{
private String title;
public static MyFragment newInstance(String title){
MyFragment fragment= new MyFragment();
fragment.setTitle(title);
return fragment;
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
TextView textView=new TextView(getActivity());
textView.setText(title);
return textView;
}
public void setTitle(String title) {
this.title = title;
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_back);
ft = getFragmentManager().beginTransaction();
ft.add(R.id.fl, MyFragment.newInstance("First"));
ft.commit()；
}
2.10监控TextView的变动
1.创建一个Watcher实现TextWatcher接口
public class CurrencyTextWatcher implements TextWatcher {
boolean mEditing;
public CurrencyTextWatcher() {
mEditing = false;
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
@Override
public synchronized void afterTextChanged(Editable s) {
if (!mEditing) {
mEditing = true;
String digits = s.toString().replaceAll("\\D", "");
NumberFormat nf = NumberFormat.getCurrencyInstance();
try {
String formatted = nf.format(Double.parseDouble(digits) / 100);
s.replace(0, s.length(), formatted);
} catch (NumberFormatException n) {
s.clear();
}
mEditing = false;
}
}
}
2.在Activity中设置Watcher监听
editText.addTextChangedListener(new CurrencyTextWatcher());
2.12消除软键盘
1.在特定的用户信息录入界面很有用处
public void hide(View view) {
InputMethodManager imm= (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(view.getWindowToken(),0);
}
2.13处理复杂的触摸事件
talk is cheap ,show you the code!
1.实现自定义的一个scrollview
public class PanGestureScrollView extends FrameLayout {
private GestureDetector mDetector;
private Scroller mScroller;
private float mInitialX, mInitialY;
private int mTouchSlop;
public PanGestureScrollView(Context context) {
this(context, null);
}
public PanGestureScrollView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public PanGestureScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context);
}
private void init(Context context) {
mDetector = new GestureDetector(context, mListener);
mScroller = new Scroller(context);
mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
}
@Override
protected void measureChild(View child, int parentWidthMeasureSpec, int parentHeightMeasureSpec) {
int childWidthMeasureSpec;
int childHeightMeasureSpec;
childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
@Override
protected void measureChildWithMargins(View child, int parentWidthMeasureSpec, int widthUsed, int parentHeightMeasureSpec, int heightUsed) {
final MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();
final int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(lp.leftMargin + lp.rightMargin, MeasureSpec.UNSPECIFIED);
final int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(lp.topMargin + lp.bottomMargin, MeasureSpec.UNSPECIFIED);
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
private GestureDetector.SimpleOnGestureListener mListener = new GestureDetector.SimpleOnGestureListener() {
@Override
public boolean onDown(MotionEvent e) {
if (!mScroller.isFinished()) {
mScroller.abortAnimation();
}
return true;
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
fling((int) -velocityX / 3, (int) -velocityY / 3);
return true;
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
scrollBy((int) distanceX, (int) distanceY);
return true;
}
};
private void fling(int i, int i1) {
if (getChildCount() > 0) {
int height = getHeight() - getPaddingBottom() - getPaddingTop();
int width = getWidth() - getPaddingLeft() - getPaddingRight();
int bottom = getChildAt(0).getHeight();
int right = getChildAt(0).getWidth();
mScroller.fling(getScrollX(), getScrollY(), i, i1, 0, Math.max(0, right - width), 0, Math.max(0, bottom - height));
invalidate();
}
}
private int clamp(int n, int my, int child) {
if (my >= child || n < 0) {
return 0;
}
if ((my + n) > child) {
return child - my;
}
return n;
}
@Override
public void computeScroll() {
if (mScroller.computeScrollOffset()) {
int oldX = getScrollX();
int oldY = getScrollY();
int x = mScroller.getCurrX();
int y = mScroller.getCurrY();
if (getChildCount() > 0) {
View child = getChildAt(0);
x = clamp(x, getWidth() - getPaddingRight() - getPaddingLeft(), child.getWidth());
y = clamp(y, getHeight() - getPaddingBottom() - getPaddingTop(), child.getHeight());
if (x != oldX || y != oldY) {
scrollTo(x, y);
}
}
}
postInvalidate();
}
@Override
public void scrollTo(int x, int y) {
if(getChildCount()>0){
View child=getChildAt(0);
x = clamp(x, getWidth() - getPaddingRight() - getPaddingLeft(), child.getWidth());
y = clamp(y, getHeight() - getPaddingBottom() - getPaddingTop(), child.getHeight());
if(x!=getScrollX()||y!=getScrollY()){
super.scrollTo(x,y);
}
}
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
switch (ev.getAction()){
case MotionEvent.ACTION_DOWN:
mInitialX=ev.getX();
mInitialY=ev.getY();
mDetector.onTouchEvent(ev);
break;
case MotionEvent.ACTION_MOVE:
final float x=ev.getX();
final float y=ev.getY();
final int yDiff= (int) Math.abs(y-mInitialY);
final int xDiff= (int) Math.abs(x-mInitialX);
if(yDiff>mTouchSlop||xDiff>mTouchSlop){
return true;
}
break;
}
return super.onInterceptTouchEvent(ev);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
return mDetector.onTouchEvent(event);
}
}
时间： 2024-11-05 13:26:48