From db03876549de543e8f0f23d09da87717d90ab8c4 Mon Sep 17 00:00:00 2001
From: liukun <953831480@qq.com>
Date: Tue, 29 Jul 2025 20:44:26 -0700
Subject: [PATCH] fix(input):fix textarea height in Multiple line placeholders
 (#3624)
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* Update App.vue

* fix:多行占位符导致文本域高度计算错误
---
 examples/sites/src/App.vue             |  1 +
 packages/renderless/src/input/index.ts | 10 ++++------
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/examples/sites/src/App.vue b/examples/sites/src/App.vue
index 38383728e..efc20b12d 100644
--- a/examples/sites/src/App.vue
+++ b/examples/sites/src/App.vue
@@ -136,6 +136,7 @@ const handleShowTinyRobot = () => {
     padding: 34px 0 0;
   }
 }
+  
 .right-panel:not(.collapsed) {
   :deep(.tr-container) {
     z-index: 9999;
diff --git a/packages/renderless/src/input/index.ts b/packages/renderless/src/input/index.ts
index 33a33c8a2..af9d5bc9f 100644
--- a/packages/renderless/src/input/index.ts
+++ b/packages/renderless/src/input/index.ts
@@ -124,7 +124,9 @@ export const calcTextareaHeight =
     const { paddingSize, borderSize, boxSizing, contextStyle } = api.calculateNodeStyling(targetElement)
 
     hiddenTextarea.setAttribute('style', `${contextStyle};${HIDDEN_STYLE}`)
-    hiddenTextarea.value = targetElement.value || targetElement.placeholder || ''
+    // 多行placeholder只计算单行高度防止撑高scrollHeight
+    const safePlaceholder = targetElement.placeholder ? targetElement.placeholder.trim().split('\n')[0] : ''
+    hiddenTextarea.value = targetElement.value || safePlaceholder || ''
 
     let height = hiddenTextarea.scrollHeight
     const textareaStyle: {
@@ -161,11 +163,7 @@ export const calcTextareaHeight =
         minHeight = props.height
       }
       if (!state.isDisplayOnly) {
-        if (props.autosize) {
-          height = Math.max(minHeight, height)
-        } else {
-          height = Math.min(minHeight, height)
-        }
+        height = Math.max(minHeight, height)
         textareaStyle.minHeight = `${Math.floor(minHeight)}px`
       } else {
         textareaStyle.minHeight = `0px`