p5.js noCanvas()用法及代碼示例

function setup() { 
  createCanvas(400, 300); 
  
  // Create buttons for creating 
  // and removing the canvas 
  createBtn = createButton("Create Canvas"); 
  createBtn.position(30, 20); 
  createBtn.mouseClicked(createDrawArea); 
  
  removeBtn = createButton("Remove Canvas"); 
  removeBtn.position(30, 50); 
  removeBtn.mouseClicked(removeDrawArea); 
} 
  
function removeDrawArea() { 
    
  // Wrap noCanvas() in a try-catch 
  // to prevent error in case there 
  // exists no canvas to remove 
  try { 
    noCanvas(); 
  } catch (e) { 
    print("No canvas found to remove"); 
    print(e); 
  } 
} 
  
function createDrawArea() { 
  
  // Create a canvas with the 
  // given dimensions 
  createCanvas(400, 300); 
} 
  
function draw() { 
  clear(); 
  background("green"); 
  textSize(20); 
  
  text("This is the canvas area", 50, 130); 
  text("Canvas height:" + height, 50, 150); 
  text("Canvas width:" + width, 50, 170); 
}