<?xml version="1.0" encoding="utf-8"?>
<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/tbl_att_summary"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:stretchColumns="1"
android:shrinkColumns="1">
<TableRow android:layout_marginTop="10dp"
android:layout_marginRight="2dp"
android:layout_marginBottom="-5dp"
android:layout_gravity="center_horizontal">
<TextView
android:text="Class"
android:paddingLeft="10dip" />
<TextView
android:text="Subject"
android:gravity="center_horizontal" />
<TextView
android:text="Time Period"
android:layout_gravity="center_horizontal|bottom"
android:gravity="center_horizontal"
android:layout_marginRight="10dp" />
<TextView
android:text="Work Days"
android:layout_marginRight="15dp" />
</TableRow>
<TableRow android:layout_marginTop="5dp"
android:id="@+id/header_row_att_summary">
<!-- first column for Class - Section -->
<TextView
android:layout_column="0"
android:id="@+id/txt_class_sec_att_summary"
android:textColor="@color/black"
android:textSize="20sp"
android:paddingLeft="10dp" />
<!-- Second column for subject -->
<TextView
android:layout_column="1"
android:id="@+id/txt_subjec_att_summary"
android:text="Chemistry"
android:textSize="20sp"
android:paddingRight="10dp"
android:layout_marginRight="5dp"
android:textColor="@color/black"
android:layout_gravity="center_horizontal"
android:layout_marginLeft="5dp" />
<!-- third column for duration (time period) for the attendance -->
<TextView
android:id="@+id/txt_time_period_att_summary"
android:text="Feb-15"
android:textColor="@color/black"
android:textSize="20sp"
android:gravity="fill_horizontal|end"
android:paddingRight="10dp"
android:layout_marginRight="5dp"
android:layout_gravity="center_horizontal" />
<!-- fourth column for the total number of working days -->
<TextView
android:id="@+id/txt_working_days_att_summary"
android:text="18"
android:textColor="@color/black"
android:textSize="20sp"
android:gravity="fill_horizontal|end"
android:paddingRight="10dp"
android:layout_marginLeft="10dp"
android:layout_gravity="center_horizontal"
android:layout_marginRight="10dp" />
</TableRow>
<View
android:layout_height="2dip"
android:background="#FF909090"/>
<TableRow
android:layout_marginTop="5dp">
<TextView
android:background="@drawable/cell_shape"
android:layout_column="0"
android:paddingLeft="5dp"
android:text="Roll No"
android:layout_weight="0.2"
android:textStyle="bold" />
<TextView
android:background="@drawable/cell_shape"
android:paddingLeft="5dp"
android:text="Name"
android:textStyle="bold" />
<TextView
android:background="@drawable/cell_shape"
android:paddingLeft="5dp"
android:text="Days Present"
android:textStyle="bold" />
<TextView
android:background="@drawable/cell_shape"
android:paddingLeft="5dp"
android:text="Percentage"
android:textStyle="bold" />
</TableRow>
<TableRow
android:id="@+id/row_att_detail"
android:layout_marginTop="0dp">
<TextView
android:id="@+id/txt_roll_no"
android:background="@drawable/cell_shape"
android:paddingLeft="5dp" />
<TextView
android:id="@+id/txt_student_name"
android:background="@drawable/cell_shape"
android:paddingLeft="5dp" />
<TextView
android:id="@+id/txt_days_present"
android:background="@drawable/cell_shape"
android:paddingLeft="5dp"/>
<TextView
android:id="@+id/txt_percentage"
android:background="@drawable/cell_shape"
android:paddingLeft="5dp"/>
</TableRow>
</TableLayout>
对应的java代码
public class ShowAttendanceSummary extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_show_attendance_summary);
// set up the header rows
TableRow header_row = (TableRow) findViewById(R.id.header_row_att_summary);
((TextView) header_row.findViewById(R.id.txt_class_sec_att_summary)).
setText((getIntent().getStringExtra("class") + "-" +
getIntent().getStringExtra("section")));
((TextView) header_row.findViewById(R.id.txt_subjec_att_summary)).
setText((getIntent().getStringExtra("subject")));
// showing month/year is slightly tricky. As we are passing strings like "current year",
// "last year", or "till date", we need get the year value
Integer yr = Calendar.getInstance().get(Calendar.YEAR);
System.out.print("year=" + Integer.toString(yr));
//Toast.makeText(getApplicationContext(), Integer.toString(yr), Toast.LENGTH_SHORT).show();
switch (getIntent().getStringExtra("year")) {
case "current_year":
((TextView) header_row.findViewById(R.id.txt_time_period_att_summary)).
setText((getIntent().getStringExtra("month") + "-" +
Integer.toString(yr)));
break;
case "last_year":
((TextView) header_row.findViewById(R.id.txt_time_period_att_summary)).
setText((getIntent().getStringExtra("month") + "-" +
Integer.toString(yr - 1)));
break;
case "till_date":
((TextView) header_row.findViewById(R.id.txt_time_period_att_summary)).
setText("Till Date");
break;
}
final TableLayout tableLayout = (TableLayout) findViewById(R.id.tbl_att_summary);
final ArrayList<TableRow> tableRows = new ArrayList<>();
// get the list of students
String tag = "AttendanceListSummary";
final String student_list_url = "http://" +
MiscFunctions.getInstance().getServerIP(getApplicationContext())
+ "/student/list/" +
getIntent().getStringExtra("class") + "/" +
getIntent().getStringExtra("section") + "/?format=json";
JsonArrayRequest jsonArrayRequest = new JsonArrayRequest
(Request.Method.GET, student_list_url, null, new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
for (int i = 0; i < response.length(); i++)
try {
JSONObject jo = response.getJSONObject(i);
// get the name of the student. We need to join first and last names
String f_name = jo.getString("fist_name");
String l_name = jo.getString("last_name");
String full_name = f_name + " " + l_name;
// get the roll number of the student
String roll_no = jo.getString("roll_number");
TableRow detail_row = (TableRow) findViewById(R.id.row_att_detail);
((TextView) detail_row.findViewById(R.id.txt_roll_no)).
setText(roll_no);
((TextView) detail_row.findViewById(R.id.txt_student_name)).
setText(full_name);
tableRows.add(detail_row);
tableLayout.addView(tableRows.get(i));
} catch (JSONException je) {
System.out.println("Ran into JSON exception " +
"while trying to fetch the list of students");
je.printStackTrace();
} catch (Exception e) {
System.out.println("Caught General exception " +
"while trying to fetch the list of students");
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
System.out.println("inside volley error handler");
// TODO Auto-generated method stub
}
});
com.classup.AppController.getInstance().addToRequestQueue(jsonArrayRequest, tag);
JSONObject params = new JSONObject();
try {
params.put("class", getIntent().getStringExtra("class"));
params.put("section", getIntent().getStringExtra("section"));
params.put("subject", getIntent().getStringExtra("subject"));
params.put("month", getIntent().getStringExtra("month"));
params.put("year", getIntent().getStringExtra("year"));
} catch (JSONException je) {
System.out.println("unable to create json for selected subjects");
je.printStackTrace();
}
}
}
可以看出，我试图在运行时向TableLayout添加行。然而，我得到了以下异常:
classup W/系统。err: java.lang.IllegalStateException:指定的孩子已经有了父母。你必须对子视图调用removeView()首先父母。
谁能看一下，并指出我在这里犯了什么错误。
您得到的异常可能属于您的代码块。
try {
JSONObject jo = response.getJSONObject(i);
// get the name of the student. We need to join first and last names
String f_name = jo.getString("fist_name");
String l_name = jo.getString("last_name");
String full_name = f_name + " " + l_name;
// get the roll number of the student
String roll_no = jo.getString("roll_number");
TableRow detail_row = (TableRow) findViewById(R.id.row_att_detail);
((TextView) detail_row.findViewById(R.id.txt_roll_no)).setText(roll_no);
((TextView) detail_row.findViewById(R.id.txt_student_name)).
setText(full_name);
tableRows.add(detail_row);
tableLayout.addView(tableRows.get(i));
}
注意事项:
视图只能附属于主视图层次结构一次。因此，如果您试图再次将已经附加的视图附加到层次结构中，您将得到一个异常。
如果你添加一个子
TableRow，你就不需要再添加TableRow到主TableLayout。