canvas 生产图片，保存到本地功能。
- canvas 组件
<view
class="r-canvas-component"
:style="{width:canvas_width/scale+'rpx',height:canvas_height/scale+'rpx'}"
:class="{'hidden':hidden}"
>
<canvas
class="r-canvas"
v-if="canvas_id"
:canvas-id="canvas_id"
:id="canvas_id"
:style="{width:canvas_width+'rpx',height:canvas_height+'rpx','transform':`scale(${r_canvas_scale})`}"
></canvas>
</view>
js
export default {
data() {
return {
system_info: {}, //system info
canvas_width: 0, //canvas width px
canvas_height: 0, //canvas height px
ctx: null, //canvas object
canvas_id: null, //canvas id
hidden: false, //Whether to hide canvas
scale: 1, //canvas scale
r_canvas_scale: 1,
if_ctx: true
}
},
methods: {
/**
* save r-canvas.vue object
* @param {Object} that
*/
// saveThis(that){
// rCanvasThis = that
// },
/**
* Draw round rect text
* @param {Object} config
* @param {Number} config.x x坐标
* @param {Number} config.y y坐标
* @param {Number} config.w 宽度
* @param {Number} config.h 高度
* @param {Number} config.radius 圆角弧度
* @param {String} config.fill_color 矩形颜色
*/
fillRoundRect(config) {
return new Promise((resolve, reject) => {
let x = this.compatibilitySize(parseFloat(config.x) * this.scale)
let y = this.compatibilitySize(parseFloat(config.y) * this.scale)
let w = this.compatibilitySize(parseFloat(config.w) * this.scale)
let h = this.compatibilitySize(parseFloat(config.h) * this.scale)
let radius = config.radius ? parseFloat(config.radius) * this.scale : 10 * this.scale
let fill_color = config.fill_color || "black"
// The diameter of the circle must be less than the width and height of the rectangle
if (2 * radius > w || 2 * radius > h) {
reject("The diameter of the circle must be less than the width and height of the rectangle")
return false;
}
this.ctx.save();
this.ctx.translate(x, y);
//
this.drawRoundRectPath({
w: w,
h: h,
radius: radius
});
this.ctx.fillStyle = fill_color
this.ctx.fill();
this.ctx.restore();
resolve()
})
},
/**
* Draws the sides of a rounded rectangle
* @param {Object} config
* @param {Number} config.w 宽度
* @param {Number} config.h 高度
* @param {Number} config.radius 圆角弧度
*/
drawRoundRectPath(config) {
this.ctx.beginPath(0);
this.ctx.arc(config.w - config.radius, config.h - config.radius, config.radius, 0, Math.PI / 2);
this.ctx.lineTo(config.radius, config.h);
this.ctx.arc(config.radius, config.h - config.radius, config.radius, Math.PI / 2, Math.PI);
this.ctx.lineTo(0, config.radius);
this.ctx.arc(config.radius, config.radius, config.radius, Math.PI, Math.PI * 3 / 2);
this.ctx.lineTo(config.w - config.radius, 0);
this.ctx.arc(config.w - config.radius, config.radius, config.radius, Math.PI * 3 / 2, Math.PI * 2);
this.ctx.lineTo(config.w, config.h - config.radius);
this.ctx.closePath();
},
/**
* Draw special Text,line wrapping is not supported
* @param {Object} config
* @param {String} config.text 文字
* @param {Number} config.x x坐标
* @param {Number} config.y y坐标
* @param {String} config.font_color 文字颜色
* @param {String} config.font_family 文字字体
* @param {Number} config.font_size 文字大小（px）
*/
drawSpecialText(params) {
let general = params.general
let list = params.list
return new Promise(async(resolve, reject) => {
if (!general) {
reject("general cannot be empty:101")
return;
} else if (list && list.length > 0) {
for (let i in list) {
if (i != 0) {
let font_size = list[i - 1].font_size ? parseFloat(list[i - 1].font_size) : 20
this.ctx.setFontSize(font_size)
general.x = parseFloat(general.x) + this.ctx.measureText(list[i - 1].text).width
}
list[i].x = general.x
list[i].y = general.y + (list[i].margin_top ? parseFloat(list[i].margin_top) : 0)
await this.drawText(list[i])
}
resolve()
} else {
reject("The length of config arr is less than 0")
return;
}
})
},
/**
* array delete empty
* @param {Object} arr
*/
arrDeleteEmpty(arr) {
let newArr = []
for (let i in arr) {
if (arr[i]) {
newArr.push(arr[i])
}
}
return newArr
},
/**
* Draw Text,support line
* @param {Object} config
* @param {String} config.text 文字
* @param {Number} config.max_width 文字最大宽度（大于宽度自动换行）
* @param {Number} config.line_height 文字上下行间距
* @param {Number} config.x x坐标
* @param {Number} config.y y坐标
* @param {String} config.font_color 文字颜色
* @param {String} config.font_family 文字字体 默认值：Arial
* @param {String} config.text_align 文字对齐方式（left/center/right）
* @param {Number} config.font_size 文字大小（px）
* @param {Boolean} config.line_through_height 中划线大小
* @param {Boolean} config.line_through_color 中划线颜色
* @param {String} config.font_style 规定文字样式
* @param {String} config.font_variant 规定字体变体
* @param {String} config.font_weight 规定字体粗细
* @param {String} config.line_through_cap 线末端类型
* @param {String} config.line_clamp 最大行数
* @param {String} config.line_clamp_hint 超过line_clamp后，尾部显示的自定义标识 如 ...
* @param {String} config.is_line_break 是否开启换行符换行
*
*/
drawText(config, configuration = {}) {
configuration['line_num'] = configuration.line_num ? configuration.line_num : 0
configuration['text_width'] = configuration.text_width ? configuration.text_width : 0
return new Promise(async(resolve, reject) => {
if (config.text) {
let draw_width = 0,
draw_height = 0,
draw_x = config.x,
draw_y = config.y
let font_size = config.font_size ? (parseFloat(config.font_size) * this.scale) : (20 * this.scale)
let font_color = config.font_color || "#000"
let font_family = config.font_family || "Arial"
let line_height = config.line_height || config.font_size || 20
let text_align = config.text_align || "left"
let font_weight = config.font_weight || "normal"
let font_variant = config.font_variant || "normal"
let font_style = config.font_style || "normal"
let line_clamp_hint = config.line_clamp_hint || '...'
let lineBreakJoinText = ""
let max_width = config.max_width ? parseFloat(config.max_width) * this.scale : 0
// checkout is line break
if (config.is_line_break) {
let splitTextArr = config.text.split(/[\n]/g)
if (splitTextArr && splitTextArr.length > 0) {
let newSplitTextArr = this.arrDeleteEmpty(splitTextArr)
if (newSplitTextArr && newSplitTextArr.length > 0) {
lineBreakJoinText = newSplitTextArr.slice(1).join("\n")
config.text = newSplitTextArr[0]
} else {
reject("Text cannot be empty:103")
return
}
} else {
reject("Text cannot be empty:102")
return
}
}
this.ctx.setFillStyle(font_color) // color
this.ctx.textAlign = text_align;
this.ctx.font = `${font_style} ${font_variant} ${font_weight} ${parseInt(font_size)}px ${font_family}`
if (configuration.text_width >= this.ctx.measureText(config.text).width) {
draw_width = configuration.text_width
} else if (max_width > 0) {
draw_width = max_width < this.ctx.measureText(config.text).width ? this.resetCompatibilitySize(max_width) : this.resetCompatibilitySize(this.ctx.measureText(config.text).width)
} else {
draw_width = this.ctx.measureText(config.text).width
}
configuration.text_width = draw_width / this.scale
if (max_width && this.compatibilitySize(this.ctx.measureText(config.text).width) > this.compatibilitySize(max_width)) {
let current_text = ""
let text_arr = config.text.split("")
for (let i in text_arr) {
if (this.compatibilitySize(this.ctx.measureText(current_text + text_arr[i]).width) > this.compatibilitySize(max_width)) {
// Hyphenation that is greater than the drawable width continues to draw
if (config.line_clamp && parseInt(config.line_clamp) == 1) {
// Subtracting the current_text tail width from the line_clamp_hint width
let current_text_arr = current_text.split('')
let json_current_text = ''
while (true) {
current_text_arr = current_text_arr.slice(1)
json_current_text = current_text_arr.join('')
if (this.compatibilitySize(this.ctx.measureText(json_current_text).width) <= this.compatibilitySize(this.ctx.measureText(line_clamp_hint).width)) {
current_text = current_text.replace(json_current_text, '')
break;
}
}
configuration.line_num += 1
this.ctx.setFontSize(parseInt(this.compatibilitySize(font_size))) // font size
this.ctx.fillText(current_text + line_clamp_hint, this.compatibilitySize(parseFloat(config.x) * this.scale), this.compatibilitySize(parseFloat(config.y) * this.scale));
} else {
configuration.line_num += 1
this.ctx.setFontSize(parseInt(this.compatibilitySize(font_size))) // font size
this.ctx.fillText(current_text, this.compatibilitySize(parseFloat(config.x) * this.scale), this.compatibilitySize(parseFloat(config.y) * this.scale));
config.text = text_arr.slice(i).join("")
config.y = config.y + line_height
if (config.line_clamp) {
config.line_clamp = parseInt(config.line_clamp) - 1
}
await this.drawText(config, configuration)
}
break;
} else {
current_text = current_text + text_arr[i]
}
}
} else {
if (config.line_through_height) {
let x = parseFloat(config.x) * this.scale
let w
let y = parseFloat(config.y) * this.scale - (font_size / 2.6)
if (text_align == "left") {
w = this.ctx.measureText(config.text).width / 1.1 + parseFloat(config.x) * this.scale
} else if (text_align == "right") {
w = parseFloat(config.x) * this.scale - this.ctx.measureText(config.text).width / 1.1
} else if (text_align == "center") {
x = parseFloat(config.x) * this.scale - this.ctx.measureText(config.text).width / 1.1 / 2
w = parseFloat(config.x) * this.scale + this.ctx.measureText(config.text).width / 1.1 / 2
}
this.drawLineTo({
x: x,
y: y,
w: w,
h: y,
line_width: config.line_through_height,
line_color: config.line_through_color,
line_cap: config.line_through_cap
})
}
configuration.line_num += 1
this.ctx.setFontSize(parseInt(this.compatibilitySize(font_size))) // font size
this.ctx.fillText(config.text, this.compatibilitySize(parseFloat(config.x) * this.scale), this.compatibilitySize(parseFloat(config.y) * this.scale));
if (config.line_clamp) {
config.line_clamp = parseInt(config.line_clamp) - 1
}
}
if (lineBreakJoinText) {
await this.drawText({...config, text: lineBreakJoinText, y: config.y + line_height }, configuration)
}
draw_height = config.font_size * configuration.line_num
draw_width = configuration.text_width
resolve({ draw_width, draw_height, draw_x, draw_y })
} else {
reject("Text cannot be empty:101")
}
})
},
/**
* Draw Line
* @param {Object} config
* @param {Object} config.x x坐标
* @param {Object} config.y y坐标
* @param {Object} config.w 线的宽度
* @param {Object} config.h 线的高度
* @param {Object} config.line_width 线的宽度
* @param {Object} config.line_color 线条颜色
*/
drawLineTo(config) {
let x = this.compatibilitySize(config.x)
let y = this.compatibilitySize(config.y)
let w = this.compatibilitySize(config.w)
let h = this.compatibilitySize(config.h)
let line_width = config.line_width ? parseFloat(config.line_width) * this.scale : 1 * this.scale
let line_color = config.line_color || "black"
let line_cap = config.line_cap || "butt"
this.ctx.beginPath()
this.ctx.lineCap = line_cap
this.ctx.lineWidth = line_width
this.ctx.strokeStyle = line_color
this.ctx.moveTo(x, y)
this.ctx.lineTo(w, h)
this.ctx.stroke()
},
/**
* Compatibility px
* @param {Object} size
*/
compatibilitySize(size) {
let canvasSize = (parseFloat(size) / 750) * this.system_info.windowWidth
canvasSize = parseFloat(canvasSize * 2)
return canvasSize
},
/**
* Restore compatibility px
* @param {Object} size
*/
resetCompatibilitySize(size) {
let canvasSize = (parseFloat(size / 2) / this.system_info.windowWidth) * 750
return canvasSize
},
/**
* Init canvas
*/
init(config) {
return new Promise(async(resolve, reject) => {
if (!config.canvas_id) {
reject("Canvas ID cannot be empty, please refer to the usage example")
return;
}
this.hidden = config.hidden
this.canvas_id = config.canvas_id
let system_info = await uni.getSystemInfoSync()
this.system_info = system_info
this.scale = config.scale && parseFloat(config.scale) > 0 ? parseInt(config.scale) : 1
this.canvas_width = (config.canvas_width ? this.compatibilitySize(config.canvas_width) : system_info.windowWidth) * this.scale
this.canvas_height = (config.canvas_height ? this.compatibilitySize(config.canvas_height) : system_info.windowHeight) * this.scale,
this.r_canvas_scale = 1 / this.scale
this.ctx = uni.createCanvasContext(this.canvas_id, this)
this.setCanvasConfig({
global_alpha: config.global_alpha ? parseFloat(config.global_alpha) : 1,
backgroundColor: config.background_color ? config.background_color : "#fff"
})
resolve()
})
},
/**
* clear canvas all path
*/
clearCanvas() {
return new Promise(async(resolve, reject) => {
if (!this.ctx) {
reject("canvas is not initialized:101")
return
} else {
this.ctx.clearRect(0, 0, parseFloat(this.canvas_width) * this.scale, parseFloat(this.canvas_height) * this.scale)
await this.draw()
resolve()
}
})
},
/**
* Set canvas config
* @param {Object} config
*/
setCanvasConfig(config) {
this.ctx.globalAlpha = config.global_alpha
this.ctx.fillStyle = config.backgroundColor
this.ctx.fillRect(0, 0, parseFloat(this.canvas_width) * this.scale, parseFloat(this.canvas_height) * this.scale)
},
/**
* set canvas width
* @param {Object} width
*/
setCanvasWidth(width) {
if (!width) {
uni.showToast({
title: 'setCanvasWidth：width error',
icon: 'none'
})
}
this.canvas_width = this.compatibilitySize(parseFloat(width)) * this.scale
this.ctx.width = this.canvas_width
},
/**
* set canvas height
* @param {Object} height
*/
setCanvasHeight(height) {
if (!height) {
uni.showToast({
title: 'setCanvasWidth：height error',
icon: 'none'
})
}
this.canvas_height = this.compatibilitySize(parseFloat(height)) * this.scale
this.ctx.height = this.canvas_height
},
/**
* Draw to filepath
*/
draw(callback) {
return new Promise((resolve, reject) => {
let stop = setTimeout(() => {
this.ctx.draw(false, setTimeout(() => {
uni.canvasToTempFilePath({
canvasId: this.canvas_id,
quality: 1,
success: (res) => {
console.log('res', res)
resolve(res)
callback && callback(res)
},
fail: (err) => {
reject(JSON.stringify(err) || "Failed to generate poster:101")
}
}, this)
}, 300))
clearTimeout(stop)
}, 300)
})
},
/**
* draw rect
* @param {Number} config.x x坐标
* @param {Number} config.y y坐标
* @param {Number} config.w 图形宽度(px)
* @param {Number} config.h 图形高度(px)
* @param {Number} config.color 图形颜色
* @param {Number} config.is_radius 是否开启圆图（1.1.6及以下版本废弃，请使用border_radius）
* @param {Number} config.border_width 边框大小
* @param {Number} config.border_color 边框颜色
*
*/
drawRect(config) {
return new Promise(async(resolve, reject) => {
if (!config.border_width || config.border_width <= 0) {
config.border_width = 0
} else {
config.border_width = parseFloat(config.border_width)
}
if (parseFloat(config.border_width) > 0) {
let sub_config = JSON.parse(JSON.stringify(config))
sub_config.border_width = 0
sub_config.w = config.w + config.border_width
sub_config.h = config.h + config.border_width
sub_config.color = config.border_color || 'black'
if (sub_config.border_radius) {
sub_config.border_radius = parseFloat(sub_config.border_radius) + parseFloat(config.border_width) / 2
}
await this.drawRect(sub_config)
}
let color = config.color || 'white'
config.x = (parseFloat(config.x) + config.border_width / 2)
config.y = (parseFloat(config.y) + config.border_width / 2)
config['color'] = color
this.ctx.fillStyle = color;
if (config.is_radius || config.border_radius) {
this.setNativeBorderRadius(config)
this.ctx.fill()
} else {
console.log('config.border_width', config.border_width)
this.ctx.fillRect(this.compatibilitySize(config.x * this.scale), this.compatibilitySize(config.y * this.scale), this.compatibilitySize(parseFloat(config.w) * this.scale), this.compatibilitySize(parseFloat(config.h) * this.scale))
}
resolve()
})
},
/**
* Draw image
* @param {Object} config
* @param {String} config.url 图片链接
* @param {Number} config.x x坐标
* @param {Number} config.y y坐标
* @param {Number} config.w 图片宽度(px)
* @param {Number} config.h 图片高度(px)
* @param {Number} config.border_width 边大小
* @param {Number} config.border_color 边颜色
* @param {Number} config.is_radius 是否开启圆图（1.1.6及以下版本废弃，请使用border_radius）
* @param {Number} config.border_radius 圆角弧度
*/
drawImage(config) {
return new Promise(async(resolve, reject) => {
if (config.url) {
let type = 0 // 1、network image 2、native image 3、base64 image
let image_url
let reg = /^https?/ig;
if (reg.test(config.url)) {
type = 1
} else {
if ((config.url.indexOf("data:image/png;base64") != -1) || config.url.indexOf("data:image/jpeg;base64") != -1 || config.url.indexOf("data:image/gif;base64") != -1) {
type = 3
} else {
type = 2
}
}
if (type == 1) {
// network image
await this.downLoadNetworkFile(config.url).then(res => { // two function
image_url = res
}).catch(err => {
reject(err)
return;
})
} else if (type == 2) {
// native image
const imageInfoResult = await uni.getImageInfo({
src: config.url
});
try {
if (imageInfoResult.length <= 1) {
reject(imageInfoResult[0].errMsg + ':404')
return
}
} catch (e) {
reject(e + ':500')
return
}
let base64 = await this.urlToBase64({ url: imageInfoResult[1].path })
// #ifdef MP-WEIXIN
await this.base64ToNative({ url: base64 }).then(res => {
image_url = res
}).catch(err => {
reject(JSON.stringify(err) + ":501")
return;
})
// #endif
// #ifndef MP-WEIXIN
image_url = base64
// #endif
} else if (type == 3) {
// #ifdef MP-WEIXIN
await this.base64ToNative({ url: config.url }).then(res => {
image_url = res
}).catch(err => {
reject(JSON.stringify(err) + ":500")
return;
})
// #endif
// #ifndef MP-WEIXIN
image_url = config.url
// #endif
} else {
reject("Other Type Errors:101")
return
}
if (config.border_width) {
let border_radius = 0
if (config.border_radius) {
let multiple = config.w / config.border_radius
border_radius = (parseFloat(config.w) + parseFloat(config.border_width)) / multiple
}
// drawRect
await this.drawRect({
x: parseFloat(config.x) - parseFloat(config.border_width) / 2,
y: parseFloat(config.y) - parseFloat(config.border_width) / 2,
w: parseFloat(config.w) + parseFloat(config.border_width),
h: parseFloat(config.h) + parseFloat(config.border_width),
color: config.border_color,
border_radius: border_radius,
border_width: config.border_width,
is_radius: config.is_radius
})
}
if (config.border_radius) {
config.color = config.color ? config.color : 'rgba(0,0,0,0)'
// 圆角有白边,+0.5的误差
config.w = config.w + 0.3
config.h = config.h + 0.3
this.setNativeBorderRadius(config)
} else if (config.is_radius) {
//已废弃 is_radius
this.ctx.setStrokeStyle("rgba(0,0,0,0)")
this.ctx.save()
this.ctx.beginPath()
this.ctx.arc(this.compatibilitySize(parseFloat(config.x) * this.scale + parseFloat(config.w) * this.scale / 2), this.compatibilitySize(parseFloat(config.y) * this.scale + parseFloat(config.h) * this.scale / 2), this.compatibilitySize(parseFloat(config.w) * this.scale / 2), 0, 2 * Math.PI, false)
this.ctx.stroke();
this.ctx.clip()
}
await this.ctx.drawImage(image_url, this.compatibilitySize(parseFloat(config.x) * this.scale), this.compatibilitySize(parseFloat(config.y) * this.scale), this.compatibilitySize(parseFloat(config.w) * this.scale), this.compatibilitySize(parseFloat(config.h) * this.scale))
this.ctx.restore() //Restore previously saved drawing context
resolve()
} else {
let err_msg = "Links cannot be empty:101"
reject(err_msg)
}
})
},
/**
* base64 to native available path
* @param {Object} config
*/
base64ToNative(config) {
return new Promise((resolve, reject) => {
let fileName = new Date().getTime()
var filePath = `${wx.env.USER_DATA_PATH}/${fileName}_rCanvas.png`
wx.getFileSystemManager().writeFile({
filePath: filePath,
data: config.url.replace(/^data:\S+\/\S+;base64,/, ''),
encoding: 'base64',
success: function() {
resolve(filePath)
},
fail: function(error) {
reject(error)
}
})
})
},
/**
* native url to base64
* @param {Object} config
*/
urlToBase64(config) {
return new Promise(async(resolve, reject) => {
if (typeof window != 'undefined') {
await this.downLoadNetworkFile(config.url).then(res => { // two function
resolve(res)
}).catch(err => {
reject(err)
})
} else if (typeof plus != 'undefined') {
plus.io.resolveLocalFileSystemURL(config.url, (obj) => {
obj.file((file) => {
let fileReader = new plus.io.FileReader()
fileReader.onload = (res) => {
resolve(res.target.result)
}
fileReader.onerror = (err) => {
reject(err)
}
fileReader.readAsDataURL(file)
}, (err) => {
reject(err)
})
}, (err) => {
reject(err)
})
} else if (typeof wx != 'undefined') {
wx.getFileSystemManager().readFile({
filePath: config.url,
encoding: 'base64',
success: function(res) {
resolve('data:image/png;base64,' + res.data)
},
fail: function(error) {
reject(error)
}
})
}
})
},
setNativeBorderRadius(config) {
let border_radius = config.border_radius ? (parseFloat(config.border_radius) * this.scale) : (20 * this.scale)
if ((parseFloat(config.w) * this.scale) < 2 * border_radius) border_radius = (parseFloat(config.w) * this.scale) / 2;
if ((parseFloat(config.h) * this.scale) < 2 * border_radius) border_radius = (parseFloat(config.h) * this.scale) / 2;
this.ctx.beginPath();
this.ctx.moveTo(this.compatibilitySize((parseFloat(config.x) * this.scale) + border_radius), this.compatibilitySize((parseFloat(config.y) * this.scale)));
this.ctx.arcTo(this.compatibilitySize((parseFloat(config.x) * this.scale) + (parseFloat(config.w) * this.scale)), this.compatibilitySize((parseFloat(config.y) * this.scale)), this.compatibilitySize((parseFloat(config.x) * this.scale) + (parseFloat(config.w) * this.scale)), this.compatibilitySize((parseFloat(config.y) * this.scale) + (parseFloat(config.h) * this.scale)), this.compatibilitySize(border_radius));
this.ctx.arcTo(this.compatibilitySize((parseFloat(config.x) * this.scale) + (parseFloat(config.w) * this.scale)), this.compatibilitySize((parseFloat(config.y) * this.scale) + (parseFloat(config.h) * this.scale)), this.compatibilitySize((parseFloat(config.x) * this.scale)), this.compatibilitySize((parseFloat(config.y) * this.scale) + (parseFloat(config.h) * this.scale)), this.compatibilitySize(border_radius));
this.ctx.arcTo((this.compatibilitySize(parseFloat(config.x) * this.scale)), this.compatibilitySize((parseFloat(config.y) * this.scale) + (parseFloat(config.h) * this.scale)), this.compatibilitySize((parseFloat(config.x) * this.scale)), this.compatibilitySize((parseFloat(config.y) * this.scale)), this.compatibilitySize(border_radius));
this.ctx.arcTo(this.compatibilitySize((parseFloat(config.x) * this.scale)), this.compatibilitySize((parseFloat(config.y) * this.scale)), this.compatibilitySize((parseFloat(config.x) * this.scale) + (parseFloat(config.w) * this.scale)), this.compatibilitySize((parseFloat(config.y) * this.scale)), this.compatibilitySize(border_radius));
this.ctx.closePath();
this.ctx.strokeStyle = config.color || config.border_color || 'rgba(0,0,0,0)'; // 设置绘制边框的颜色
this.ctx.stroke();
this.ctx.save()
this.ctx.clip();
},
/**
* Download network file
* @param {Object} url : download url
*/
downLoadNetworkFile(url) {
return new Promise((resolve, reject) => {
uni.downloadFile({
url,
success: (res) => {
if (res.statusCode == 200) {
resolve(res.tempFilePath)
} else {
reject("Download Image Fail:102")
}
},
fail: (err) => {
reject("Download Image Fail:101")
}
})
})
},
/**
* Save image to natice
* @param {Object} filePath ： native imageUrl
*/
saveImage(filePath) {
return new Promise((resolve, reject) => {
if (!filePath) {
reject("FilePath cannot be null:101")
return;
}
// #ifdef H5
var createA = document.createElement("a");
createA.download = filePath;
createA.href = filePath;
document.body.appendChild(createA);
createA.click();
createA.remove();
resolve()
// #endif
// #ifndef H5
uni.saveImageToPhotosAlbum({
filePath: filePath,
success: (res) => {
resolve(res)
},
fail: (err) => {
reject(err)
}
})
// #endif
})
}
}
}
画canvas
<view>
<uni-canvas-to-image ref="rCanvas" ></uni-canvas-to-image>
</view>
js
// 宝贝信息分享页生成图片
drawCanvas (){
this.$nextTick(async ()=>{
try{
uni.showLoading({
title: "生成中..."
});
// 初始化
await this.$refs.rCanvas.init({
canvas_id:"rCanvas",
canvas_width: this.canvasWidth,
canvas_height: this.canvasHeight
})
// 画图片，网络图
let imgAvaW = parseInt(235 / 2 * this.getAdapt())
let imgAvaH = parseInt(235 / 2 * this.getAdapt())
let imgAvaL = parseInt(205 / 2 * this.getAdapt())
let imgAvaT = parseInt(61 / 2 * this.getAdapt())
await this.$refs.rCanvas.drawImage({
url: 'https//:xxxx/image/avatar.png', // 注：图片格式不能为 svg
x: imgAvaL,
y: imgAvaT,
w: imgAvaW,
h: imgAvaH,
border_radius:'28rpx'
}).catch(err_msg=>{
uni.showToast({
title:err_msg,
icon:"none"
})
})
// 画文字
let fontSize = parseInt(48 / 2 * this.getAdapt())
let fontSizeL = parseInt(200 / 2 * this.getAdapt())
let fontSizeT = parseInt(368 / 2 * this.getAdapt())
let maxW = parseInt(240 / 2 * this.getAdapt())
await this.$refs.rCanvas.drawText({
text: this.userInfo.name,
max_width: maxW,
x:fontSizeL,
y:fontSizeT,
line_clamp: 2, // 超过两行，自动隐藏...
font_color:"#080808",
font_family:"JRound500",
font_size: fontSize
}).catch(err_msg=>{
uni.showToast({
title:err_msg,
icon:"none"
})
})
// 画图片，本地图片
let imgSexT = parseInt(330 / 2 * this.getAdapt())
let imgSexaL = parseInt(460 / 2 * this.getAdapt())
let imgSexW = parseInt(40 / 2 * this.getAdapt())
let imgSexH = parseInt(40 / 2 * this.getAdapt())
let imgUrl = ’./images/xx.png‘
await this.$refs.rCanvas.drawImage({
url: imgUrl,
x: imgSexaL,
y: imgSexT,
w: imgSexW,
h: imgSexH,
}).catch(err_msg=>{
uni.showToast({
title:err_msg,
icon:"none"
})
})
// 画二维码
let imgQrT = parseInt(500 / 2 * this.getAdapt())
let imgQraL = parseInt(160 / 2 * this.getAdapt())
let imgQrW = parseInt(320 / 2 * this.getAdapt())
let imgQrH = parseInt(320 / 2 * this.getAdapt())
await this.$refs.rCanvas.drawImage({
url: this.shareQr,
x: imgQraL,
y: imgQrT,
w: imgQrW,
h: imgQrH,
}).catch(err_msg=>{
uni.showToast({
title:err_msg,
icon:"none"
})
})
// 生成图片
await this.$refs.rCanvas.draw((res)=>{
// res.tempFilePath：生成成功，返回base64图片
uni.hideLoading();
})
}catch(e){
this.$refs.qrPopup.close()
uni.showToast({
title: '生成失败',
icon: 'none'
})
}
})
},
// 自适应尺寸
getAdapt() {
let w = 0;
wx.getSystemInfo({
success: (res) => {
w = res.windowWidth / 375; //按照750的屏宽，设计稿宽 / 2 * w
},
})
return w // 返回比率
},
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