微信小程序图片选择区域裁剪实现方法(3)
局域裁剪
areaType:function(){ var that = this; var propor = that.data.propor; var canvasW = that.data.canvasW; var canvasH = that.data.canvasH; var cutH = that.data.cutH; var nowCutW = (Number(canvasW)*propor)/100 var nowCutH = (Number(cutH)*propor)/100 const ctx = wx.createCanvasContext('cutImg'); ctx.setGlobalAlpha(0.4) ctx.drawImage(that.data.img, 0, 0, canvasW, canvasH) ctx.setFillStyle('red') ctx.fillRect(0,0, nowCutW, nowCutH) ctx.draw() that.setData({ nowCutW:nowCutW, nowCutH:nowCutH, cutType:false }) },
局域裁剪上方的滑动选择红框根据宽度等比例缩放
areaChange:function(e){ var that = this; var propor = e.detail.value; var canvasW = that.data.canvasW; var canvasH = that.data.canvasH; var cutH = that.data.cutH; var nowCutW = (Number(canvasW)*propor)/100 var nowCutH = (Number(cutH)*propor)/100 const ctx = wx.createCanvasContext('cutImg'); ctx.setGlobalAlpha(0.4) ctx.drawImage(that.data.img, 0, 0, canvasW, canvasH) ctx.setFillStyle('red') ctx.fillRect(that.data.cutX||0, that.data.cutY||0,nowCutW, nowCutH) ctx.draw() that.setData({ nowCutW:nowCutW, nowCutH:nowCutH, propor:propor }) },
重新裁剪回到初始选择图片的页面
// 重新裁剪 againBtn:function(){ var that = this; var data = that.data this.setData({ prienFlag:true, alreay:true }) const ctx = wx.createCanvasContext('cutImg'); ctx.setGlobalAlpha(0.4) ctx.drawImage(data.img, 0, 0, data.canvasW, data.canvasH) ctx.setFillStyle('red') ctx.fillRect(that.data.cutX||0, that.data.cutY||0, data.nowCutW||data.canvasW, data.nowCutH||data.cutH) ctx.draw() },
现在IOS还有个坑就是裁剪不了,官方正在修复不知道什么时候好
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