fix(bug): copy bug

src/controllers/selection.js

@@ -440,7 +440,7 @@ const selection = {
                     }
 
                     if(c_value == null){
-                        c_value = " ";
+                        c_value = "";
                     }
 
                     column += c_value;
@@ -500,7 +500,7 @@ const selection = {
                     }
 
                     column = replaceHtml(column, {"style": style, "span": ""});
-                    column += " ";
+                    column += "";
                 }
 
                 column += '</td>';
@@ -527,9 +527,10 @@ const selection = {
             // }, 10);
 
             var oInput = document.createElement('input');
+            oInput.setAttribute('readonly', 'readonly');
             oInput.value = cpdata;
             document.body.appendChild(oInput);
-            oInput.select(); // 选择对象
+            oInput.setSelectionRange(0, cpdata.length);
             document.execCommand("Copy");
             oInput.style.display='none';
             document.body.removeChild(oInput);