fix(textarea): support responsive update of value

src/textarea/textarea.less

@@ -1,10 +1,10 @@
 @import '../common/style/index.less';
 
-@textarea-height: 72px; // 指定文本框高度
+@textarea-height: 144rpx; // 指定文本框高度
 @textarea-vertical-padding: 32rpx; // 文本框垂直方向间距
 @textarea-horizontal-padding: 32rpx; // 文本框水平方向间距
 @textarea-text-line-height: 48rpx; // 输入框文本行高
-@textarea-label-line-height: 44px; // 标签文本行高
+@textarea-label-line-height: 44rpx; // 标签文本行高
 @textarea-label-padding-bottom: @spacer;
 @textarea-indicator-text-line-height: 40rpx; // 计数器文本行高
 @textarea-indicator-text-padding-top: @spacer; // 计数器文本顶部间距
@@ -61,7 +61,7 @@
       border: 0;
       resize: none;
       font-size: @textarea-text-font-size;
-      color: @textarea-text-font-size;
+      color: @textarea-text-color;
       line-height: @textarea-text-line-height;
     }
   }

src/textarea/textarea.ts

@@ -37,10 +37,9 @@ export default class Textarea extends SuperComponent {
     count: 0,
   };
 
-  lifetimes = {
-    ready() {
-      const { value } = this.properties;
-      this.updateValue(value);
+  observers = {
+    value(val) {
+      this.updateValue(val);
     },
   };
 
@@ -50,18 +49,18 @@ export default class Textarea extends SuperComponent {
       if (maxcharacter > 0 && !Number.isNaN(maxcharacter)) {
         const { length, characters } = getCharacterLength('maxcharacter', value, maxcharacter);
         this.setData({
-          value: characters,
+          computedValue: characters,
           count: length,
         });
       } else if (maxlength > 0 && !Number.isNaN(maxlength)) {
         const { length, characters } = getCharacterLength('maxlength', value, maxlength);
         this.setData({
-          value: characters,
+          computedValue: characters,
           count: length,
         });
       } else {
         this.setData({
-          value,
+          computedValue: value,
           count: value ? String(value).length : 0,
         });
       }
@@ -70,7 +69,7 @@ export default class Textarea extends SuperComponent {
     onInput(event) {
       const { value } = event.detail;
       this.updateValue(value);
-      this.triggerEvent('change', { value: this.data.value });
+      this.triggerEvent('change', { value: this.data.computedValue });
     },
     onFocus(event) {
       this.triggerEvent('focus', {

src/textarea/textarea.wxml

@@ -11,7 +11,7 @@
       placeholder="{{placeholder}}"
       placeholder-class="{{classPrefix}}__placeholder"
       placeholder-style="{{placeholderStyle}}"
-      value="{{value}}"
+      value="{{computedValue}}"
       auto-focus="{{autofocus}}"
       fixed="{{fixed}}"
       focus="{{focus}}"