构造JSON数组字符串

string result = "[";

var fileArray = files.ToArray();

for (int i = 0; i < fileArray.Length; i++) {

string baseName = fileArray[i].Name;

string extension = fileArray[i].Extension;

result += "{name:'"+baseName+"',extension:'"+extension+"'}";

if (i != (fileArray.Length - 1)) {

result += ",";

}

//extjs中解析json：

var responseJSON = Ext.JSON.decode(response.responseText);