update zh-cn/application-dev/media/image.md.

Signed-off-by: N冯泽悟 <fengzewu@huawei.com>

zh-cn/application-dev/media/image.md

@@ -35,9 +35,9 @@ image.createPixelMap(color, opts, (err, pixelmap) => {
         region: { size: { height: 1, width: 2 }, x: 0, y: 0 }
     }
     pixelmap.readPixels(area,() => {
-        var bufferArr = new Uint8Array(area.pixels);
-        var res = true;
-        for (var i = 0; i < bufferArr.length; i++) {
+        let bufferArr = new Uint8Array(area.pixels);
+        let res = true;
+        for (let i = 0; i < bufferArr.length; i++) {
             console.info(' buffer ' + bufferArr[i]);
             if(res) {
                 if(bufferArr[i] == 0) {
@@ -52,9 +52,9 @@ image.createPixelMap(color, opts, (err, pixelmap) => {
     // 用于存像素
     const readBuffer = new ArrayBuffer(96);
     pixelmap.readPixelsToBuffer(readBuffer,() => {
-        var bufferArr = new Uint8Array(readBuffer);
-        var res = true;
-        for (var i = 0; i < bufferArr.length; i++) {
+        let bufferArr = new Uint8Array(readBuffer);
+        let res = true;
+        for (let i = 0; i < bufferArr.length; i++) {
             if(res) {
                 if (bufferArr[i] !== 0) {
                     res = false;
@@ -69,9 +69,9 @@ image.createPixelMap(color, opts, (err, pixelmap) => {
     pixelmap.writePixels(area,() => {
         const readArea = { pixels: new ArrayBuffer(20), offset: 0, stride: 8, region: { size: { height: 1, width: 2 }, x: 0, y: 0 }}
         pixelmap.readPixels(readArea,() => {
-            var readArr = new Uint8Array(readArea.pixels);
-            var res = true;
-            for (var i = 0; i < readArr.length; i++) {
+            let readArr = new Uint8Array(readArea.pixels);
+            let res = true;
+            for (let i = 0; i < readArr.length; i++) {
                 if(res) {
                     if (readArr[i] !== 0) {
                         res = false;
@@ -88,9 +88,9 @@ image.createPixelMap(color, opts, (err, pixelmap) => {
     pixelmap.writeBufferToPixels(writeColor).then(() => {
         const readBuffer = new ArrayBuffer(96);
         pixelmap.readPixelsToBuffer(readBuffer).then (() => {
-            var bufferArr = new Uint8Array(readBuffer);
-            var res = true;
-            for (var i = 0; i < bufferArr.length; i++) {
+            let bufferArr = new Uint8Array(readBuffer);
+            let res = true;
+            for (let i = 0; i < bufferArr.length; i++) {
                 if(res) {
                     if (bufferArr[i] !== i) {
                         res = false;
@@ -187,10 +187,10 @@ imageSourceApi.createPixelMap().then(pixelmap => {
     console.log('Succeeded in creating pixelmap.');
 
     // 用于获取像素每行字节数
-    var num = pixelmap.getBytesNumberPerRow();
+    let num = pixelmap.getBytesNumberPerRow();
 
     // 用于获取像素总字节数
-    var pixelSize = pixelmap.getPixelBytesNumber();
+    let pixelSize = pixelmap.getPixelBytesNumber();
 
     // 用于获取pixelmap信息
     pixelmap.getImageInfo().then( imageInfo => {});
@@ -257,7 +257,7 @@ imageSourceApi.updateData(array, false, 0, 10,(error, data)=> {})
 public async init(surfaceId: any) {
 
     // 服务端代码，创建ImageReceiver
-    var receiver = image.createImageReceiver(8 * 1024, 8, image.ImageFormat.JPEG, 1);
+    let receiver = image.createImageReceiver(8 * 1024, 8, image.ImageFormat.JPEG, 1);
 
     // 获取Surface ID
     receiver.getReceivingSurfaceId((err, surfaceId) => {