有两个活动，其中第一个活动显示带有一些数据的表格布局（此数据作为来自 Web 应用程序的响应获取），当单击一行时，它启动活动 2，该活动显示其他表格布局。在同一屏幕中有一个按钮，单击该按钮会重新启动活动 1。现在如何防止活动 1 再次访问服务器并获取响应。它应该显示在活动 2 开始之前获取的数据。
这是我的活动之一：
public class CaptureActivity extends Activity {
//private String url = "http";
private String url = "http:";
FetchEmployeeAsyncTask employeeAsyncTask;
SelectedEmployeeAsyncTask selectedEmployeeAsyncTask;
private ArrayList<Employee> employees = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
employeeAsyncTask = new FetchEmployeeAsyncTask(this);
selectedEmployeeAsyncTask = new SelectedEmployeeAsyncTask(this);
employeeAsyncTask.execute(new String[] {url});
System.out.println("Status "+employeeAsyncTask.getStatus());
setContentView(R.layout.activity_capture);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_capture, menu);
return true;
}
public void showEmployees(ArrayList<Employee> employees) {
// TODO Auto-generated method stub
System.out.println("Status 2 "+employeeAsyncTask.getStatus());
TableLayout employeeTable = (TableLayout) findViewById(R.id.main_table);
TableRow header = new TableRow(this);
header.setId(100);
header.setBackgroundColor(Color.rgb(255, 165, 0));
//header.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
TextView empCodeHeader = new TextView(this);
empCodeHeader.setId(200);
empCodeHeader.setText("Employee Code");
empCodeHeader.setTextSize(16);
empCodeHeader.setPadding(2,2,2,2);
empCodeHeader.setWidth(200);
header.addView(empCodeHeader);
TextView empNameHeader = new TextView(this);
empNameHeader.setId(201);
empNameHeader.setText("Employee Name");
empNameHeader.setTextSize(16);
empNameHeader.setPadding(2,2,2,2);
empNameHeader.setWidth(300);
header.addView(empNameHeader);
employeeTable.addView(header);//, new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
for(int i=0; i<employees.size();i++){
final Employee employee = (Employee) employees.get(i);
int count = 0;
TableRow empData = new TableRow(this);
empData.setId(300+count);
empData.setClickable(true);
/*empData.setLayoutParams(new LayoutParams(
LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT ));*/
//tr.setClickable(true);
final TextView empCode = new TextView(this);
empCode.setId(300+count);
empCode.setText(employee.getCode());
empCode.setTextSize(16);
empCode.setPadding(2,2, 2, 2);
empData.addView(empCode);
final TextView empName = new TextView(this);
empName.setId(300+count);
empName.setText(employee.getFirstName()+","+employee.getLastName());
empName.setTextSize(16);
empName.setPadding(2, 2, 2, 2);
empData.addView(empName);
employeeTable.addView(empData); /*, new TableLayout.LayoutParams(
LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT));*/
count++;
empData.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
String employeeUrl = "http://192.168.2.166:8680/capture/clientRequest.do?r=employeeList&code="+employee.getCode()+"&cid=0&mode=full";
selectedEmployeeAsyncTask.execute(new String[] {employeeUrl});
}
});
}
}
public void display(ArrayList<Employee> employees){
System.out.println("in here !! ");
HashMap<String, String> empMap = null;
for (int i = 0;i<employees.size(); i++){
final Employee empDetails = (Employee) employees.get(i);
empMap = new HashMap<String, String>();
empMap.put("Honorific", empDetails.getHonorific());
empMap.put("First Name", empDetails.getFirstName());
empMap.put("Last Name", empDetails.getLastName());
empMap.put("Call Name", empDetails.getCallName());
empMap.put("Gender", empDetails.getGender());
empMap.put("Designation", empDetails.getDesignation());
empMap.put("Level", empDetails.getLevel());
empMap.put("Stream", empDetails.getStream());
empMap.put("Mobile", empDetails.getMobile());
empMap.put("Phone", empDetails.getPhone());
empMap.put("Email", empDetails.getEmail());
empMap.put("DOB", empDetails.getDob());
empMap.put("DOJ", empDetails.getDoj());
empMap.put("Present Address", empDetails.getPresentAddress());
empMap.put("Permanent Address", empDetails.getPermanentAddress());
empMap.put("Status", empDetails.getStatus());
empMap.put("Company Id", empDetails.getCompanyId());
empMap.put("PM User Id", empDetails.getPMUserId());
empMap.put("PM Code", empDetails.getPmCode());
empMap.put("PM First Name", empDetails.getPmFirstName());
empMap.put("PM Last Name", empDetails.getPmLastName());
empMap.put("PM Call Name", empDetails.getPmCallName());
empMap.put("PM Email", empDetails.getPmEmail());
empMap.put("Nationality", empDetails.getNationality());
empMap.put("Blood Group", empDetails.getBloodGroup());
empMap.put("Marital Status", empDetails.getMaritalStatus());
empMap.put("Language", empDetails.getLanguage());
empMap.put("Guardian Name", empDetails.getGuardianName());
empMap.put("Guardian Type", empDetails.getGuardianType());
empMap.put("Desk No", empDetails.getDeskNo());
empMap.put("Extn No", empDetails.getExtnNo());
empMap.put("Designation Id", empDetails.getDesignationId());
empMap.put("Level Id", empDetails.getLevelId());
empMap.put("Stream Id", empDetails.getStreamId());
empMap.put("Created By", empDetails.getCreatedBy());
empMap.put("Date Created", empDetails.getDateCreated());
empMap.put("Personal Email", empDetails.getPersonalEmail());
empMap.put("Photo Id", empDetails.getPhotoId());
empMap.put("Place of Issue", empDetails.getPlaceOfIssue());
empMap.put("Date of Issue", empDetails.getDateOfIssue());
empMap.put("Inactive Status Type", empDetails.getInactiveStatusType());
empMap.put("Date Status", empDetails.getDateStatus());
empMap.put("Image", empDetails.getImage());
}
Intent displaySelectedIntent = new Intent(this,DisplaySelectedActivity.class);
displaySelectedIntent.putExtra("empDetailsMap", empMap);
startActivity(displaySelectedIntent);
}
/**
* @return the employees
*/
public ArrayList<Employee> getEmployees() {
return employees;
}
/**
* @param employees the employees to set
*/
public void setEmployees(ArrayList<Employee> employees) {
this.employees = employees;
}
}
这是我的活动2：
public class DisplaySelectedActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_display_selected);
HashMap<String , String> listemp = (HashMap<String, String>)getIntent().getSerializableExtra("empDetailsMap");
TableLayout displaySelected = (TableLayout) findViewById(R.id.displaySelected);
for (Map.Entry entry : listemp.entrySet()) {
TableRow tr_inner = new TableRow(DisplaySelectedActivity.this);
if(!entry.getKey().toString().equalsIgnoreCase("Image")){
TextView key = new TextView(this);
key.setId(400);
key.setText(entry.getKey().toString());
key.setTextSize(15);
key.setTextColor(Color.RED);
//key.setBackgroundColor(Color.YELLOW);
tr_inner.addView(key);
TextView value = new TextView(this);
value.setId(500);
value.setText(entry.getValue().toString());
value.setTextSize(15);
tr_inner.addView(value);
/*Bitmap bm = BitmapFactory.decodeFile(pathName)
ImageView empImage = (ImageView) findViewById(R.id.empImage);
empImage.setImageBitmap(bm)
*/
displaySelected.addView(tr_inner);/*, new TableLayout.LayoutParams(
LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT));*/
}
else
{
System.out.println("in else1111");
byte[] imageAsBytes = Base64.decode(entry.getValue().toString().getBytes(), 0);
//Bitmap bm = BitmapFactory.decodeFile(entry.getValue().toString());
ImageView empImage = (ImageView) findViewById(R.id.empImage);
empImage.setImageBitmap( BitmapFactory.decodeByteArray(imageAsBytes, 0, imageAsBytes.length));
}
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_display_selected, menu);
return true;
}
public void goBack(View view){
Intent intent = new Intent(this,CaptureActivity.class);
startActivity(intent);
}}
当在活动 2 中按下按钮时 goBack() 被调用...