使用corona中的setDrawMode更改绘图模式。

我想在 Corona 中改变绘图模式(drawMode)。但它仅在物体一开始掉落在地面上时有效。当物体躺在地面上时，我无法更改绘图模式。能否有人帮我解决这个问题？这里是带有 onKeyEvent 函数的代码。

local physics = require "physics"

function onKeyEvent( event )

if (event.keyName == "d") then
    physics.setDrawMode( "debug" );
end

if (event.keyName == "n") then
    physics.setDrawMode( "normal" );
end

if (event.keyName == "h") then
    physics.setDrawMode( "hybrid" );
end

end

Runtime:addEventListener( "key", onKeyEvent );

physics.start();
physics.setScale( 60 )
physics.setGravity( 0, 9.8 ) -- 初始引力向下

local groundIm = display.newRect(0, 400, 320, 20);
groundIm:setFillColor(255, 255, 255);
local ground = physics.addBody(groundIm, "static", {friction = 0.5});

local boxIm = display.newRect(100,100,30,30);
boxIm:setFillColor(0, 0, 255);

local triangleShape = { 0,-35, 37,30, -37,30 };

local body = physics.addBody(boxIm, "dynamic", {shape = triangleShape});