あるキャンバスから別のキャンバスに複数の画像をドラッグ アンド ドロップするにはどうすればよいですか? 上司からこのタスクを与えられてから 3 日経ちましたが、私は HTML5 を初めて使用するので、これを行うことができません。Google で検索しましたが、1 つの画像でしか機能しませんでした。この件で私を助けてください。
これは私が1つの画像のために得たものです:
<pre>
<script>
window.onload = function ()
{
var canvas1 = document.getElementById("cvs1");
var canvas2 = document.getElementById("cvs2");
var context1 = canvas1.getContext('2d');
var context2 = canvas2.getContext('2d');
var imageXY = {x: 5, y: 5};
/**
* This draws the image to the canvas
*/
function Draw ()
{
//Clear both canvas first
context1.clearRect(0,0,canvas1.width,canvas1.height);
context2.clearRect(0,0,canvas2.width,canvas2.height);
//Draw a red rectangle around the image
if (state && state.dragging) {
state.canvas.getContext('2d').strokeStyle = 'red';
state.canvas.getContext('2d').strokeRect(imageXY.x - 2.5,
imageXY.y - 2.5,
state.image.width + 5,
state.image.height + 5);
}
// Now draw the image
state.canvas.getContext('2d').drawImage(state.image, imageXY.x, imageXY.y);
}
canvas2.onclick =
canvas1.onclick = function (e)
{
if (state && state.dragging) {
state.dragging = false;
Draw();
return;
}
var mouseXY = RGraph.getMouseXY(e);
state.canvas = e.target;
if ( mouseXY[0] > imageXY.x
&& mouseXY[0] < (imageXY.x + state.image.width)
&& mouseXY[1] > imageXY.y
&& mouseXY[1] < (imageXY.y + state.image.height)) {
state.dragging = true;
state.originalMouseX = mouseXY[0];
state.originalMouseY = mouseXY[1];
state.offsetX = mouseXY[0] - imageXY.x;
state.offsetY = mouseXY[1] - imageXY.y;
}
}
canvas1.onmousemove =
canvas2.onmousemove = function (e)
{
if (state.dragging) {
state.canvas = e.target;
var mouseXY = RGraph.getMouseXY(e);
// Work how far the mouse has moved since the mousedon event was triggered
var diffX = mouseXY[0] - state.originalMouseX;
var diffY = mouseXY[1] - state.originalMouseY;
imageXY.x = state.originalMouseX + diffX - state.offsetX;
imageXY.y = state.originalMouseY + diffY - state.offsetY;
Draw();
e.stopPropagation();
}
}
/**
* Load the image on canvas1 initially and set the state up with some defaults
*/
state = {}
state.dragging = false;
state.canvas = document.getElementById("cvs1");
state.image = new Image();
state.image.src = 'images/logo.png';
state.offsetX = 0;
state.offsetY = 0;
state.image.onload = function ()
{
Draw();
}
}
</script>
<canvas id="cvs1" width="400" height="125" style="float: left">[No canvas support]</canvas>
<canvas id="cvs2" width="400" height="125" style="float: left; margin-left: 100px">[No canvas support]</canvas>
</pre>