效果：

使用：

var that = this;

const ctx = wx.createCanvasContext('savePic');

var colorText = '肤色晶莹白皙，肤质细腻有透明感，适合搭配一些颜色明亮、轻快一点的色彩，营造轻盈感。';

that.draw_long_text(colorText, ctx, 46, 1271);

 

封装：

//canvas文字自动换行封装

/*

longtext 文案

cxt 对应的canvas

begin_width 开始位置的X坐标

begin_height 开始位置的Y坐标

*/

draw_long_text: function (longtext, cxt, begin_width, begin_height) {

var linelenght = 45;//行高

var text = "";

var count = 0;

var begin_width = begin_width;

var begin_height = begin_height;

var stringLenght = longtext.length;

var newtext = longtext.split("");

var context = cxt;

context.textAlign = 'left';

for (var i = 0; i <= stringLenght; i++) {

if (count == 22) {//count一行显示多少个字

context.fillText(text, begin_width, begin_height);

begin_height = begin_height + linelenght;

text = "";

count = 0;

}

if (i == stringLenght) {

context.fillText(text, begin_width, begin_height);

}

var text = text + newtext[0];

count++;

newtext.shift();

}

},