Android自定義日歷控件(繼承系統控件實現)
主要步驟
- 編寫布局
- 繼承LinearLayout設置子控件
- 設置數據
- 繼承TextView實現有圓圈背景的TextView
- 添加Attribute
- 添加長按事件
1.編寫布局
<?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:orientation="vertical">
<RelativeLayout
android:id="@+id/header"
android:layout_width="match_parent"
android:layout_height="30dp">
<ImageView
android:id="@+id/btn_pre"
android:layout_width="30dp"
android:layout_height="30dp"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:src="@mipmap/ic_launcher" />
<ImageView
android:id="@+id/btn_next"
android:layout_width="30dp"
android:layout_height="30dp"
android:layout_alignParentEnd="true"
android:layout_alignParentRight="true"
android:src="@mipmap/ic_launcher" />
<TextView
android:id="@+id/txtData"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_centerInParent="true"
android:gravity="center"
android:text="@string/app_name" />
</RelativeLayout>
<LinearLayout
android:id="@+id/week_header"
android:layout_width="match_parent"
android:layout_height="40dp"
android:orientation="horizontal">
<TextView
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:gravity="center"
android:text="1" />
<TextView
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:gravity="center"
android:text="2" />
<TextView
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:gravity="center"
android:text="3" />
<TextView
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:gravity="center"
android:text="4" />
<TextView
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:gravity="center"
android:text="5" />
<TextView
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:gravity="center"
android:text="6" />
<TextView
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:gravity="center"
android:text="7" />
</LinearLayout>
<GridView
android:id="@+id/grid"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:numColumns="7" />
</LinearLayout>
2.繼承LinearLayout設置子控件
public class CalendarView extends LinearLayout {
private ImageView btnPre;
private ImageView btnNext;
private TextView txtData;
private GridView gridView;
private Calendar calendar = Calendar.getInstance();
private String displayFormat;
public NewViewListener viewListener;
public void setViewListener(NewViewListener viewListener) {
this.viewListener = viewListener;
}
public CalendarView(Context context) {
super(context);
}
public CalendarView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
initControl(context, attrs);
}
public CalendarView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
initControl(context, attrs);
}
private void initControl(Context context, AttributeSet attributeSet) {
bindControl(context);
bindControlEvent();
setAttribute(attributeSet);
renderCalender();
}
private void bindControl(Context context) {
LayoutInflater.from(context).inflate(R.layout.new_view, this);
btnNext = (ImageView) findViewById(R.id.btn_next);
btnPre = (ImageView) findViewById(R.id.btn_pre);
txtData = (TextView) findViewById(R.id.txtData);
gridView = (GridView) findViewById(R.id.grid);
}
private void bindControlEvent() {
btnNext.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
calendar.add(Calendar.MONTH, +1);
renderCalender();
}
});
btnPre.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
calendar.add(Calendar.MONTH, -1);
renderCalender();
}
});
}
}
3.設置數據
private void renderCalender() {
//返回"月+日"格式的數據
SimpleDateFormat sdf = new SimpleDateFormat(displayFormat, Locale.CHINA);
txtData.setText(sdf.format(calendar.getTime()));
ArrayList<Date> cells = new ArrayList<>();
Calendar calendar2 = (Calendar) this.calendar.clone();
//設置月的第一天為1
calendar2.set(Calendar.DAY_OF_MONTH, 1);
//獲取當前周數的前一天
int prevDays = calendar2.get(Calendar.DAY_OF_WEEK) - 1;
//運算日歷加上加前一周
calendar2.add(Calendar.DAY_OF_MONTH, -prevDays);
int maxCellCount = 6 * 7;
//將日歷里的日期數據添加到ArrayList
while (cells.size() < maxCellCount) {
cells.add(calendar2.getTime());
calendar2.add(Calendar.DAY_OF_MONTH, 1);
}
gridView.setAdapter(new MyAdapter(getContext(), cells));
gridView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
if (viewListener == null) {
return false;
} else {
viewListener.onItemLongPress((Date) parent.getItemAtPosition(position));
return true;
}
}
});
}
private class MyAdapter extends ArrayAdapter<Date> {
LayoutInflater layoutInflater;
MyAdapter(@NonNull Context context, ArrayList<Date> dates) {
super(context, R.layout.calendar_text_day, dates);
layoutInflater = LayoutInflater.from(context);
}
@NonNull
@Override
public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
Date date = getItem(position);
if (convertView == null) {
convertView = layoutInflater.inflate(R.layout.calendar_text_day, parent, false);
}
int day = date.getDate();
((CalendarTextView) convertView).setText(String.valueOf(day));
Date now = new Date();
boolean isSameMonth = false;
if (date.getMonth() == now.getMonth()) {
isSameMonth = true;
}
if (isSameMonth) {
((CalendarTextView) convertView).setTextColor(Color.DKGRAY);
}
if (now.getDate() == date.getDate() && now.getMonth() == date.getMonth() && now.getYear() == date.getYear()) {
((CalendarTextView) convertView).setNow(true);
}
return convertView;
}
}
4. 圓圈背景TextView
public class CalendarTextView extends AppCompatTextView {
private Paint paint;
private boolean isNow = false;
public void setNow(boolean now) {
isNow = now;
}
public CalendarTextView(Context context) {
super(context);
}
public CalendarTextView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
initControl();
}
public CalendarTextView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
initControl();
}
private void initControl() {
paint = new Paint();
paint.setStyle(Paint.Style.STROKE);
paint.setColor(Color.RED);
paint.setStrokeWidth(2);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (isNow) {
canvas.translate(getWidth() / 2, getHeight() / 2);
canvas.drawCircle(0, 0, getWidth() / 2, paint);
setTextColor(Color.RED);
}
}
}
5.添加Attribute
-
添加attrs文件
<?xml version="1.0" encoding="utf-8"?> <resources> <declare-styleable name="CalendarView"> <attr name="dateFormat" format="string" /> </declare-styleable> </resources> -
將Arrtibute參數設置到控件
private void setAttribute(AttributeSet attributeSet) { TypedArray ta = getContext().obtainStyledAttributes(attributeSet, R.styleable.CalendarView); try { displayFormat = ta.getString(R.styleable.CalendarView_dateFormat); if (displayFormat == null) { displayFormat = "MMM yyy"; } } finally { ta.recycle(); } } -
在布局中加入命名空間引入
<com.example.jiyang.newview.CalendarView xmlns:CalendarView="http://schemas.android.com/apk/res/com.example.jiyang.newview" android:id="@+id/newView" android:layout_width="match_parent" android:layout_height="match_parent" android:padding="10dp" CalendarView:dateFormat="MMMM yyyy" />
6.添加長按事件
-
定義長按接口
public interface NewViewListener { void onItemLongPress(Date day); } -
CalenderView中調用
gridView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
if (viewListener == null) {
return false;
} else {
viewListener.onItemLongPress((Date) parent.getItemAtPosition(position));
return true;
}
}
});
```
- Activity中實現接口方法
@Override
public void onItemLongPress(Date day) {
DateFormat df = SimpleDateFormat.getDateInstance();
Toast.makeText(this, df.format(day), Toast.LENGTH_SHORT).show();
}
```
總結
-
Attribute的使用
- 定義attrs文件
- 注意命名空間。自定義View不能使用
app:，而要使用xmlns:自定義一個命名空間 - TypedArray放入
try{}finaly{}中，要在finally中釋放TypedArraytypedArray.recycle()
通過繼承布局實現自定義View時，加載布局
需要LayoutInflater.from(context).inflate(R.layout.new_view, this);不能LayoutInflater.from(context).inflate(R.layout.new_view, this,false);
