GridfieldManager不会跨越整个屏幕宽度

Question

好的，我正在为Blackberry Bold 9700开发，并且我正在尝试获得1x4网格（1行，4列）以跨越BlackBerry屏幕的整个宽度，但它的幅度不断。我的意思是，默认情况下将网格对齐，如果我能使整个网格跨越整个宽度（那没关系），那就很好。一些开发人员可以告诉我我在做什么错吗？我以为您只是在声明新网格时在构造函数中添加gridfieldmanager.use_all_width，但它仍然对我不起作用。

final class App3_MainScreen extends MainScreen {
private int numColumns, size;
// Constructor
App3_MainScreen() {
    // declare a layout manager to take care of all the layout stuff
    numColumns = 4;
    size = 4;

    VerticalFieldManager vfm = new VerticalFieldManager();
    vfm.add(new LabelField("using all width & long label...", LabelField.ELLIPSIS | Field.FIELD_HCENTER));

    int borderHeight = Display.getHeight()/2;g
    int borderWidth = Display.getWidth()/2;

    Manager gridFieldManager = new GridFieldManager(1, 4, GridFieldManager.USE_ALL_WIDTH | GridFieldManager.AUTO_SIZE);    // 1 row and 4 columns
    gridFieldManager.add(new ButtonField(""+borderHeight, Field.FIELD_HCENTER));
    gridFieldManager.add(new ButtonField("222", Field.FIELD_HCENTER));
    gridFieldManager.add(new ButtonField("333", Field.FIELD_HCENTER));
    gridFieldManager.add(new ButtonField(""+borderWidth, Field.FIELD_RIGHT));

    // set padding around each buttonField - top=0, right=5, bottom=0, left=5
    gridFieldManager.setPadding(0, 5, 0, 5);
    int gfmHeight = 48 * (size / numColumns);
    gridFieldManager.setBorder(BorderFactory.createSimpleBorder(
            new XYEdges(borderHeight/10, 0, borderHeight/10, 0), // top, right, bottom, left
            Border.STYLE_DASHED));

    add(gridFieldManager);
}}

Answer 1

我在下面提供了一个解决问题的示例。它基于您提供的原始代码，但已清理并制作通用，以确保清晰。

基本上，GridFieldManager不明确支持USE_ALL_WIDTH。作为经理，它继承了这个常数，但其文档并未表明它是受支持的状态。最好的选择是依靠fixed_size状态，并根据显示的大小（DisplayWidth / NumColumns）计算每个列的宽度。然后，您可以使用GridFieldManager＃setColumnProperty（）来定义列的固定宽度。

确保考虑到列应用的填充物，您就可以了。

希望这可以帮助。

/**
 * Shows an example implementation of how to have a GridFieldManager
 * sized to the width of the Display.
 */
final class ScreenWidthGridExample extends MainScreen
{
    /**
     * Number of rows in the grid.
     */
    private static final int NUM_ROWS = 1;

    /**
     * Number of columns in the grid.
     */
    private static final int NUM_COLUMNS = 4;

    /**
     * The grid's column padding.
     */
    private static final int COLUMN_PADDING = 5;

    /**
     * Toggle switch to show the border around the grid.
     */
    private static final boolean SHOW_BORDER = true;

    /**
     * Allocated a new instance of the ScreenWidthGridExample.
     */
    ScreenWidthGridExample() {
        // Set up the GridFieldManager
        GridFieldManager gfm =
                new GridFieldManager(NUM_ROWS, NUM_COLUMNS, 
                GridFieldManager.FIXED_SIZE);
        gfm.setColumnPadding(COLUMN_PADDING);
        if(SHOW_BORDER) {
            gfm.setBorder(BorderFactory.createSimpleBorder(
                    new XYEdges(0, 0, 0, 0), // top, right, bottom, left
                    Border.STYLE_DASHED));
        }
        add(gfm);

        // Size the columns of the GridFieldManager. Make sure to calculate
        // for the padding applied to the columns.
        int columnWidth = (Display.getWidth() / NUM_COLUMNS) - 
                gfm.getColumnPadding();
        for(int i = 0; i < NUM_COLUMNS; i++) {
            gfm.setColumnProperty(i, GridFieldManager.FIXED_SIZE, columnWidth);
        }

        // Populate the columns.
        gfm.add(new ButtonField("1", Field.FIELD_HCENTER));
        gfm.add(new ButtonField("2", Field.FIELD_HCENTER));
        gfm.add(new ButtonField("3", Field.FIELD_HCENTER));
        gfm.add(new ButtonField("4", Field.FIELD_HCENTER));
    }
}