Android自定义日历控件(继承系统控件实现)

2022-09-16 08:14:42

Android自定义日历控件(继承系统控件实现)

主要步骤

编写布局
继承LinearLayout设置子控件
设置数据
继承TextView实现有圆圈背景的TextView
添加Attribute
添加长按事件

1.编写布局

<?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.继承LinearLayout设置子控件

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.设置数据

private void renderCalender() {

        //返回"月+日"格式的数据

        SimpleDateFormat sdf = new SimpleDateFormat(displayFormat, Locale.CHINA);

        txtData.setText(sdf.format(calendar.getTime()));

        ArrayList<Date> cells = new ArrayList<>();

        Calendar calendar2 = (Calendar) this.calendar.clone();

        //设置月的第一天为1

        calendar2.set(Calendar.DAY_OF_MONTH, 1);

        //获取当前周数的前一天

        int prevDays = calendar2.get(Calendar.DAY_OF_WEEK) - 1;

        //运算日历加上加前一周

        calendar2.add(Calendar.DAY_OF_MONTH, -prevDays);

        int maxCellCount = 6 * 7;

        //将日历里的日期数据添加到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. 圆圈背景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>

将Arrtibute参数设置到控件

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();

    }

}

在布局中加入命名控件引入

<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.添加长按事件

定义长按接口

public interface NewViewListener {

    void onItemLongPress(Date day);

}

CalenderView中调用

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;

}

}

});

3. Activity中实现接口方法

@Override

public void onItemLongPress(Date day) {

DateFormat df = SimpleDateFormat.getDateInstance();

Toast.makeText(this, df.format(day), Toast.LENGTH_SHORT).show();

}

```

总结

Attribute的使用
1. 定义attrs文件
2. 注意命名空间。自定义View不能使用app:，而要使用xmlns:自定义一个命名空间
3. TypedArray放入try{}finaly{}中，要在finally中释放TypedArray typedArray.recycle()
通过继承布局实现自定义View时，加载布局

需要LayoutInflater.from(context).inflate(R.layout.new_view, this);不能LayoutInflater.from(context).inflate(R.layout.new_view, this,false);

码农公寓

Android自定义日历控件(继承系统控件实现)

1.编写布局

2.继承LinearLayout设置子控件

3.设置数据

4. 圆圈背景TextView

5.添加Attribute

6.添加长按事件

总结

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