如何在GridView中按日期、起止时间定位单元格？（附适配器代码）

Hey there! Let's work through getting those colored course blocks perfectly positioned in your schedule GridView app. Here's a step-by-step approach tailored to your existing code:

1. Expand Your Data Structure #

Right now your GridViewItem only holds a title, but we need extra info to map courses to specific cells. Let's create a separate Course class for your schedule entries (or extend your existing item class):

public class Course {
    private String subjectTitle;
    private int dayIndex; // e.g., 0 = Monday, 1 = Tuesday—matches your GridView columns
    private int startRow; // Which row your course starts on (e.g., row 3 = 9:00 AM)
    private int endRow; // Which row your course ends on
    private int color; // Background color for the course block

    // Constructor, getters, and setters
    public Course(String subjectTitle, int dayIndex, int startRow, int endRow, int color) {
        this.subjectTitle = subjectTitle;
        this.dayIndex = dayIndex;
        this.startRow = startRow;
        this.endRow = endRow;
        this.color = color;
    }

    // Getters for all fields
    public String getSubjectTitle() { return subjectTitle; }
    public int getDayIndex() { return dayIndex; }
    public int getStartRow() { return startRow; }
    public int getEndRow() { return endRow; }
    public int getColor() { return color; }
}

Keep your original GridViewItem for base cell content (like time labels on the left or day names at the top), and add a separate list of Course objects to store your schedule data.

2. Update Your Grid Item Layout #

Modify gridview_item.xml to support overlaying course blocks on top of the base cell content using a FrameLayout to stack views:

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="2dp">

    <!-- Base cell text (time/day labels) -->
    <TextView
        android:id="@+id/item_title"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        android:textSize="12sp"/>

    <!-- Colored course block -->
    <View
        android:id="@+id/course_block"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:visibility="gone"
        android:background="@drawable/course_block_rounded"/>

    <!-- Course title (only visible on the first row of the course) -->
    <TextView
        android:id="@+id/course_title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="4dp"
        android:textColor="@android:color/white"
        android:textSize="10sp"
        android:visibility="gone"/>

</FrameLayout>

Create a drawable course_block_rounded.xml for adjustable rounded corners:

<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <corners android:radius="8dp"/>
</shape>

3. Modify the Adapter to Handle Course Positioning #

Update your GridviewAdapter to calculate each cell's row/column, then match it to your course data:

public class GridviewAdapter extends BaseAdapter { 
    private ArrayList<GridViewItem> gridCellData; 
    private ArrayList<Course> courseList; // Add this list of courses
    private LayoutInflater layoutInflater;
    private static final int COLUMN_COUNT = 7; // Adjust to your number of days/columns

    public GridviewAdapter(Context context, ArrayList<GridViewItem> gridCellData, ArrayList<Course> courseList){ 
        this.gridCellData = gridCellData; 
        this.courseList = courseList;
        layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
    } 

    @Override public int getCount() { return gridCellData.size(); } 
    @Override public Object getItem(int position) { return gridCellData.get(position); } 
    @Override public long getItemId(int position) { return position; } 

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
        GridViewHolder gridViewHolder; 
        if(convertView == null){ 
            convertView = layoutInflater.inflate(R.layout.gridview_item, parent, false); 
            gridViewHolder = new GridViewHolder(); 
            gridViewHolder.itemTitle = convertView.findViewById(R.id.item_title);
            gridViewHolder.courseBlock = convertView.findViewById(R.id.course_block);
            gridViewHolder.courseTitle = convertView.findViewById(R.id.course_title);
            convertView.setTag(gridViewHolder); 
        } else { 
            gridViewHolder = (GridViewHolder) convertView.getTag(); 
        } 

        // Calculate current cell's row and column
        int currentRow = position / COLUMN_COUNT;
        int currentCol = position % COLUMN_COUNT;

        // Set base cell text (time/day labels)
        gridViewHolder.itemTitle.setText(gridCellData.get(position).getSub_title());

        // Reset course views to hidden by default
        gridViewHolder.courseBlock.setVisibility(View.GONE);
        gridViewHolder.courseTitle.setVisibility(View.GONE);

        // Check if any course should appear in this cell
        for(Course course : courseList){
            if(course.getDayIndex() == currentCol && currentRow >= course.getStartRow() && currentRow <= course.getEndRow()){
                // Show the colored course block
                gridViewHolder.courseBlock.setBackgroundColor(course.getColor());
                gridViewHolder.courseBlock.setVisibility(View.VISIBLE);

                // Only show the course title on the first row of the course
                if(currentRow == course.getStartRow()){
                    gridViewHolder.courseTitle.setText(course.getSubjectTitle());
                    gridViewHolder.courseTitle.setVisibility(View.VISIBLE);
                }

                // Adjust rounded corners to make the course look like a single continuous block
                GradientDrawable bg = (GradientDrawable) gridViewHolder.courseBlock.getBackground();
                float[] cornerRadii = new float[8]; // [top-left, top-right, bottom-right, bottom-left] ×2

                if(currentRow == course.getStartRow()){
                    // Round top corners
                    cornerRadii[0] = 8f;
                    cornerRadii[1] = 8f;
                    cornerRadii[2] = 8f;
                    cornerRadii[3] = 8f;
                }
                if(currentRow == course.getEndRow()){
                    // Round bottom corners
                    cornerRadii[4] = 8f;
                    cornerRadii[5] = 8f;
                    cornerRadii[6] = 8f;
                    cornerRadii[7] = 8f;
                }
                bg.setCornerRadii(cornerRadii);
            }
        }

        return convertView; 
    } 

    static class GridViewHolder{ 
        TextView itemTitle; 
        View courseBlock;
        TextView courseTitle;
    } 
}

4. Map Dates & Times to Rows/Columns #

The final step is converting your raw date/time data into dayIndex, startRow, and endRow:

• Days: Map your date (e.g., "2024-05-20" = Monday) to an index 0-6 (match your GridView's column order).
• Times: Choose a time slot interval (e.g., 30 minutes per row). Convert start/end times to row numbers (e.g., 8:00 AM = row 0, 8:30 AM = row 1, 9:00 AM = row 2).

Example Mapping Logic: #

// Convert a time string like "09:00" to a row index
public int timeToRow(String timeStr){
    String[] parts = timeStr.split(":");
    int hour = Integer.parseInt(parts[0]);
    int minute = Integer.parseInt(parts[1]);
    // Assuming first row is 8:00 AM, each row represents 30 minutes
    return ((hour - 8) * 2) + (minute / 30);
}

This will ensure your courses line up perfectly with the correct GridView cells.

内容的提问来源于stack exchange，提问作者Dyki