DeviceProfile定义了Launcher的很多属性，比如图标的大小、间距等。在Luancher.java的onCreate方法中初始化
//方向 mDeviceProfile = getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE ? app.getInvariantDeviceProfile().landscapeProfile : app.getInvariantDeviceProfile().portraitProfile; //设置控件摆放位置 mDeviceProfile.layout(this);代码太多，只分析几个经常改动相关的方法。
Public class DeviceProfile{ /**计算所有应用程序菜单的按钮尺寸*/ private void computeAllAppsButtonSize(Context context){ } /**更新可用的间距*/ private void updateAvailableDimensions(DisplayMetrics dm, Resources res){ //调用updateIconSize方法 } /**重点分析这个方法，Launcher的搜索栏、热门应用、文件夹、文字的宽高的计算 *如果想增加行列数，可以适当的调整图标大小、间距。 */ private void updateIconSize(float scale, int drawablePadding, Resources res, DisplayMetrics dm) { iconSizePx = (int) (Utilities.pxFromDp(inv.iconSize, dm) * scale); iconTextSizePx = (int) (Utilities.pxFromSp(inv.iconTextSize, dm) * scale); iconDrawablePaddingPx = drawablePadding; hotseatIconSizePx = (int) (Utilities.pxFromDp(inv.hotseatIconSize, dm) * scale); // Search Bar searchBarSpaceWidthPx = Math.min(widthPx, res.getDimensionPixelSize(R.dimen.dynamic_grid_search_bar_max_width)); searchBarSpaceHeightPx = getSearchBarTopOffset() + res.getDimensionPixelSize(R.dimen.dynamic_grid_search_bar_height); // Calculate the actual text height Paint textPaint = new Paint(); textPaint.setTextSize(iconTextSizePx); FontMetrics fm = textPaint.getFontMetrics(); cellWidthPx = iconSizePx; //cellHeightPx = iconSizePx + iconDrawablePaddingPx + (int) Math.ceil(fm.bottom - fm.top); cellHeightPx = iconSizePx + iconDrawablePaddingPx + (int) Math.ceil(fm.bottom - fm.top) + 2 * edgeMarginPx; final float scaleDps = res.getDimensionPixelSize(R.dimen.dragViewScale); dragViewScale = (iconSizePx + scaleDps) / iconSizePx; // Hotseat hotseatBarHeightPx = iconSizePx + 4 * edgeMarginPx; hotseatCellWidthPx = iconSizePx; hotseatCellHeightPx = iconSizePx; // Folder folderCellWidthPx = cellWidthPx + 3 * edgeMarginPx; //folderCellHeightPx = cellHeightPx + edgeMarginPx; folderCellHeightPx = cellHeightPx + 3 * edgeMarginPx; folderBackgroundOffset = -edgeMarginPx; folderIconSizePx = iconSizePx + 2 * -folderBackgroundOffset; }