stretch能够根据是否有滚动条能够动态选择，而不需要主动选择

src/core/wrapper/layout/flex/flex.horizontal.js

@@ -40,12 +40,15 @@ BI.FlexHorizontalLayout = BI.inherit(BI.Layout, {
         w.element.css({
             position: "relative"
         });
-        if (o.columnSize[i] !== "auto") {
-            if (!(o.horizontalAlign === BI.HorizontalAlign.Stretch && (o.columnSize[i] === "fill" || o.columnSize[i] === ""))) {
-                w.element.addClass("f-s-n");
+        if (o.columnSize[i] === "fill" || o.columnSize[i] === "") {
+            if (o.horizontalAlign !== BI.HorizontalAlign.Stretch) {
+                if (o.scrollable === true || o.scrollx === true) {
+                    w.element.addClass("f-s-n");
+                }
             }
         }
         if (o.columnSize[i] > 0) {
+            w.element.addClass("f-s-n");
             w.element.width(o.columnSize[i] === "" ? "" : (o.columnSize[i] <= 1 ? ((o.columnSize[i] * 100).toFixed(1) + "%") : (o.columnSize[i] / BI.pixRatio + BI.pixUnit)));
         }
         if (o.columnSize[i] === "fill") {

src/core/wrapper/layout/flex/flex.vertical.js

@@ -39,12 +39,15 @@ BI.FlexVerticalLayout = BI.inherit(BI.Layout, {
         w.element.css({
             position: "relative"
         });
-        if (o.rowSize[i] !== "auto") {
-            if (!(o.verticalAlign === BI.VerticalAlign.Stretch && (o.rowSize[i] === "fill" || o.rowSize[i] === ""))) {
-                w.element.addClass("f-s-n");
+        if (o.rowSize[i] === "fill" || o.rowSize[i] === "") {
+            if (o.verticalAlign !== BI.VerticalAlign.Stretch) {
+                if (o.scrollable === true || o.scrolly === true) {
+                    w.element.addClass("f-s-n");
+                }
             }
         }
         if (o.rowSize[i] > 0) {
+            w.element.addClass("f-s-n");
             w.element.height(o.rowSize[i] === "" ? "" : (o.rowSize[i] <= 1 ? ((o.rowSize[i] * 100).toFixed(1) + "%") : (o.rowSize[i] / BI.pixRatio + BI.pixUnit)));
         }
         if (o.rowSize[i] === "fill") {

src/core/wrapper/layout/flex/wrapper/flex.wrapper.horizontal.js

@@ -36,12 +36,15 @@ BI.FlexWrapperHorizontalLayout = BI.inherit(BI.Layout, {
         w.element.css({
             position: "relative"
         });
-        if (o.columnSize[i] !== "auto") {
-            if (!(o.horizontalAlign === BI.HorizontalAlign.Stretch && (o.columnSize[i] === "fill" || o.columnSize[i] === ""))) {
-                w.element.addClass("f-s-n");
+        if (o.columnSize[i] === "fill" || o.columnSize[i] === "") {
+            if (o.horizontalAlign !== BI.HorizontalAlign.Stretch) {
+                if (o.scrollable === true || o.scrollx === true) {
+                    w.element.addClass("f-s-n");
+                }
             }
         }
         if (o.columnSize[i] > 0) {
+            w.element.addClass("f-s-n");
             w.element.width(o.columnSize[i] === "" ? "" : (o.columnSize[i] <= 1 ? ((o.columnSize[i] * 100).toFixed(1) + "%") : (o.columnSize[i] / BI.pixRatio + BI.pixUnit)));
         }
         if (o.columnSize[i] === "fill") {

src/core/wrapper/layout/flex/wrapper/flex.wrapper.vertical.js

@@ -36,12 +36,15 @@ BI.FlexWrapperVerticalLayout = BI.inherit(BI.Layout, {
         w.element.css({
             position: "relative"
         });
-        if (o.rowSize[i] !== "auto") {
-            if (!(o.verticalAlign === BI.VerticalAlign.Stretch && (o.rowSize[i] === "fill" && o.rowSize[i] === ""))) {
-                w.element.addClass("f-s-n");
+        if (o.rowSize[i] === "fill" || o.rowSize[i] === "") {
+            if (o.verticalAlign !== BI.VerticalAlign.Stretch) {
+                if (o.scrollable === true || o.scrolly === true) {
+                    w.element.addClass("f-s-n");
+                }
             }
         }
         if (o.rowSize[i] > 0) {
+            w.element.addClass("f-s-n");
             w.element.height(o.rowSize[i] === "" ? "" : (o.rowSize[i] <= 1 ? ((o.rowSize[i] * 100).toFixed(1) + "%") : (o.rowSize[i] / BI.pixRatio + BI.pixUnit)));
         }
         if (o.rowSize[i] === "fill") {