修改memo默认高度，初始化进入后粘贴内容可调节。

Unit1.LgXhdpiPh.fmx

 inherited Form1_LgXhdpiPh: TForm1_LgXhdpiPh
   ClientHeight = 720
   ClientWidth = 450
+  FormFactor.Height = 720
   OnShow = Formshow
   DesignerMasterStyle = 3
   inherited Image1: TImage

Unit1.pas

@@ -249,8 +249,8 @@ begin
   end
   else
   begin
-    Memo1.Lines.clear;
     Memo1.height := Form1.height - 226; // 将meno控件恢复到默认高度
+    Memo1.Lines.clear;
   end;
   FWantExit := True;
 
@@ -262,6 +262,7 @@ begin
 
   SetFileName(sUntitled);
   Label1.text := '当前文件：' + sUntitled + '.txt';
+  Memo1.height := 436;
 
 end;
 
@@ -274,7 +275,7 @@ begin
   i := Memo1.selstart;
   // showmessage(inttostr(i));
 
-  if (i > 0) and (Memo1.height > 470) then
+  if (i>0) and (Memo1.height > 430) then
   begin
     Memo1.height := 383;
     Memo1.selstart := i;