我正在通过 c# JSON webservice 从我的 sql 数据库中获取数据，并在按下按钮时将其显示在 android 应用程序的表中。
android 应用程序和 c# webservice 之间的连接成功建立但是当我尝试单击按钮查看数据时，它通过异常“JSONArray 失败”。
我认为 json 数组存在一些问题，但由于我刚刚开始学习 JSON Web 服务，所以无法弄清楚它是什么。程序运行成功完全没有错误。
c# webservice 代码在这里：
public string getData()
{
if (con.State == ConnectionState.Closed)
{
con.Open();
}
SqlCommand command = new SqlCommand("SELECT * FROM Student where CAST(Student.[date] AS DATE) = CAST(GETDATE() AS DATE)", con);
SqlDataReader reader = command.ExecuteReader();
if (reader.Read())
{
return "1";
}
else
{
return "0";
}
}
android活动代码在这里：
public class StudentActivity extends Activity
{
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.student);
Button button2 = (Button) findViewById(R.id.button2);
button2.setOnClickListener(new View.OnClickListener()
{
public void onClick(View view)
{
String rs = "";
InputStream is = null;
try{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://10.0.2.2:51220/Service1.svc/getData?");
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
Log.e("log_tag", "connection success ");
// Toast.makeText(getApplicationContext(), "pass", Toast.LENGTH_SHORT).show();
}
catch(Exception e)
{
Log.e("log_tag", "Error in http connection "+e.toString());
Toast.makeText(getApplicationContext(), "Connection fail", Toast.LENGTH_SHORT).show();
}
//convert response to string
try
{
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null)
{
sb.append(line + "\n");
// Toast.makeText(getApplicationContext(), "Input Reading pass", Toast.LENGTH_SHORT).show();
}
is.close();
rs=sb.toString();
}
catch(Exception e)
{
Log.e("log_tag", "Error converting rs "+e.toString());
Toast.makeText(getApplicationContext(), " Input reading fail", Toast.LENGTH_SHORT).show();
}
//parse json data
try
{
JSONArray jArray = new JSONArray(rs);
String re=jArray.getString(jArray.length()-1);
TableLayout tv=(TableLayout) findViewById(R.id.table);
tv.removeAllViewsInLayout();
int flag=1;
for(int i=-1;i<jArray.length()-1;i++)
{
TableRow tr=new TableRow(StudentActivity.this);
tr.setLayoutParams(new LayoutParams(
LayoutParams.FILL_PARENT,
LayoutParams.WRAP_CONTENT));
if(flag==1)
{
TextView b6=new TextView(StudentActivity.this);
b6.setText("ID");
b6.setTextColor(Color.BLUE);
b6.setTextSize(15);
tr.addView(b6);
TextView b19=new TextView(StudentActivity.this);
b19.setPadding(10, 0, 0, 0);
b19.setTextSize(15);
b19.setText("First Name");
b19.setTextColor(Color.BLUE);
tr.addView(b19);
TextView b29=new TextView(StudentActivity.this);
b29.setPadding(10, 0, 0, 0);
b29.setText("Last Name");
b29.setTextColor(Color.BLUE);
b29.setTextSize(15);
tr.addView(b29);
TextView b4=new TextView(StudentActivity.this);
b4.setPadding(10, 0, 0, 0);
b4.setText("Project");
b4.setTextColor(Color.BLUE);
b4.setTextSize(15);
tr.addView(b4);
TextView b5=new TextView(StudentActivity.this);
b5.setPadding(10, 0, 0, 0);
b5.setText("Date and Time");
b5.setTextColor(Color.BLUE);
b5.setTextSize(15);
tr.addView(b5);
tv.addView(tr);
final View vline = new View(StudentActivity.this);
vline.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.FILL_PARENT, 2));
vline.setBackgroundColor(Color.BLUE);
tv.addView(vline);
flag=0;
}
else
{
JSONObject json_data = jArray.getJSONObject(i);
Log.i("log_tag","id: "+json_data.getInt("f1")+
", firstname: "+json_data.getString("f2")+
", lastname: "+json_data.getInt("f3") +
", project: "+json_data.getString("f4")+
", datetime: "+json_data.getString("f5"));
TextView b=new TextView(StudentActivity.this);
String stime=String.valueOf(json_data.getInt("f1"));
b.setText(stime);
b.setTextColor(Color.RED);
b.setTextSize(15);
tr.addView(b);
TextView b1=new TextView(StudentActivity.this);
b1.setPadding(10, 0, 0, 0);
b1.setTextSize(15);
String stime1=json_data.getString("f2");
b1.setText(stime1);
b1.setTextColor(Color.WHITE);
tr.addView(b1);
TextView b2=new TextView(StudentActivity.this);
b2.setPadding(10, 0, 0, 0);
String stime2=String.valueOf(json_data.getInt("f3"));
b2.setText(stime2);
b2.setTextColor(Color.RED);
b2.setTextSize(15);
tr.addView(b2);
TextView b3=new TextView(StudentActivity.this);
b3.setPadding(10, 0, 0, 0);
String stime3=String.valueOf(json_data.getInt("f4"));
b3.setText(stime3);
b3.setTextColor(Color.WHITE);
b3.setTextSize(15);
tr.addView(b3);
TextView b4=new TextView(StudentActivity.this);
b4.setPadding(10, 0, 0, 0);
String stime4=String.valueOf(json_data.getInt("f5"));
b4.setText(stime4);
b4.setTextColor(Color.RED);
b4.setTextSize(15);
tr.addView(b4);
tv.addView(tr);
final View vline1 = new View(StudentActivity.this);
vline1.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.FILL_PARENT, 1));
vline1.setBackgroundColor(Color.WHITE);
tv.addView(vline1);
}
}
}
catch(JSONException e)
{
Log.e("log_tag", "Error parsing data "+e.toString());
Toast.makeText(getApplicationContext(), "JsonArray fail", Toast.LENGTH_SHORT).show();
}
}
});
}
}
我在 android manifest.xml 文件中使用它：
<uses-permission android:name="android.permission.INTERNET"/>
程序抛出此异常：
catch(JSONException e)
{
Log.e("log_tag", "Error parsing data "+e.toString());
Toast.makeText(getApplicationContext(), "JsonArray fail", Toast.LENGTH_SHORT).show();
}
我没有收到任何与 NetworkOnMainThreadException 相关的错误。
我在 android 2.2 和 2.3 模拟器上运行我的程序，但面临同样的问题，我只想在姜饼上部署我的应用程序。
谢谢