我正在尝试创建一个简单的应用程序，它基本上是一个跟踪号码的跟踪器。大学生每个科目的课程。该应用程序特定于我的大学时间表。这个想法是我有3个活动：main.java，Sublist.java和editcrap.java。 main.java充当启动画面并启动Sublist活动。
在子列表活动中，用户显示的布局显示（TextView）（按钮）（Counter_TextView）水平相对于彼此。其中有7个垂直对齐。
单击菜单按钮时：（编辑主题参数）出现，单击该文件会将用户带到editcrap.java活动，其中用户输入在相应的EditText框中获取，询问每个相应（TextView）的主题名称和总数Sublist活动中与（Counter_TextView）对应的类数。单击“确定”按钮，数据将通过bak传递到“子列表”活动以进行显示和操作。
完成此操作后，我需要一种方法来存储数据，以便下次打开应用程序时，wud会保留其先前的字符串，而不是。类值的。这是我遇到关闭错误或没有数据保留错误的地方。这是我的代码...反对某人请告诉我wat m doin错了？我已经苦苦挣扎了几天:)我基本上需要应用程序来维护2个文件，其中一个包含字符串和其他需要从Sublist.java活动中读取和显示的数字，因为我们需要应用程序所做的任何更改用户也可以反映到原始文件中
//Sublist.java:
package com.shuaib669.bunkrecord;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
public class Sublist extends Activity{
double[] no_of_classes = new double[7];
int count[]= new int[7];
double cutOff = 0.3;
String[] newText = new String[7];
String[] newNum = new String[7];
String countString = null;
TextView subject[] = new TextView[7];
TextView counter[] = new TextView[7]; //sub11 is counter text view label
Button button[] = new Button[7]; //button1 is the increment button
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//Assigning Views to objects.
subject[0] = (TextView) findViewById(R.id.textView1);
counter[0] = (TextView) findViewById(R.id.counter1);
button[0] = (Button) findViewById(R.id.button1);
subject[1] = (TextView) findViewById(R.id.textView2);
counter[1] = (TextView) findViewById(R.id.counter2);
button[1] = (Button) findViewById(R.id.button2);
subject[2] = (TextView) findViewById(R.id.textView3);
counter[2] = (TextView) findViewById(R.id.counter3);
button[2] = (Button) findViewById(R.id.button3);
subject[3] = (TextView) findViewById(R.id.textView4);
counter[3] = (TextView) findViewById(R.id.counter4);
button[3] = (Button) findViewById(R.id.button4);
subject[4] = (TextView) findViewById(R.id.textView5);
counter[4] = (TextView) findViewById(R.id.counter5);
button[4] = (Button) findViewById(R.id.button5);
subject[5] = (TextView) findViewById(R.id.textView6);
counter[5] = (TextView) findViewById(R.id.counter6);
button[5] = (Button) findViewById(R.id.button6);
subject[6] = (TextView) findViewById(R.id.textView7);
counter[6] = (TextView) findViewById(R.id.counter7);
button[6] = (Button) findViewById(R.id.button7);
try {
// open the file for reading
DataInputStream in= new DataInputStream(openFileInput(getFilesDir() + "/" + "subject.txt"));
// if file the available for reading
if (in!= null) {
// prepare the file for reading
String line;
int x=0;
// read every line of the file into the line-variable, on line at the time
while(in.readLine() != null) {
// do something with the strings from the file
line=DataInputStream.readUTF(in);
subject[x].setTextColor(Color.BLACK);
subject[x].setText(line);
x+=1;
}
}
// close the file again
in.close();
}
catch (Exception e) {
e.printStackTrace();// do something if the myfilename.txt does not exits
}
button[0].setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
if(count[0]>=(no_of_classes[0]*cutOff)){
counter[0].setTextColor(Color.RED);
countString = "" +(++count[0]); //Convert from int to String to set in your textview::
counter[0].setText(countString);
}
else{
countString = "" +(++count[0]); //Convert from int to String to set in your textview::
counter[0].setText(countString);
}
}
});
button[1].setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
if(count[1]>=(no_of_classes[1]*cutOff)){
counter[1].setTextColor(Color.RED);
countString = "" +(++count[1]); //Convert from int to String to set in your textview::
counter[1].setText(countString);
}
else{
countString = "" +(++count[1]); //Convert from int to String to set in your textview::
counter[1].setText(countString);
}
}
});
button[2].setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
if(count[2]>=(no_of_classes[2]*cutOff)){
counter[2].setTextColor(Color.RED);
countString = "" +(++count[2]); //Convert from int to String to set in your textview::
counter[2].setText(countString);
}
else{
countString = "" +(++count[2]); //Convert from int to String to set in your textview::
counter[2].setText(countString);
}
}
});
button[3].setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
if(count[3]>=(no_of_classes[3]*cutOff)){
counter[3].setTextColor(Color.RED);
countString = "" +(++count[3]); //Convert from int to String to set in your textview::
counter[3].setText(countString);
}
else{
countString = "" +(++count[3]); //Convert from int to String to set in your textview::
counter[3].setText(countString);
}
}
});
button[4].setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
if(count[4]>=(no_of_classes[4]*cutOff)){
counter[4].setTextColor(Color.RED);
countString = "" +(++count[4]); //Convert from int to String to set in your textview::
counter[4].setText(countString);
}
else{
countString = "" +(++count[4]); //Convert from int to String to set in your textview::
counter[4].setText(countString);
}
}
});
button[5].setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
if(count[5]>=(no_of_classes[5]*cutOff)){
counter[5].setTextColor(Color.RED);
countString = "" +(++count[5]); //Convert from int to String to set in your textview::
counter[5].setText(countString);
}
else{
countString = "" +(++count[5]); //Convert from int to String to set in your textview::
counter[5].setText(countString);
}
}
});
button[6].setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
if(count[6]>=(no_of_classes[6]*cutOff)){
counter[6].setTextColor(Color.RED);
countString = "" +(++count[6]); //Convert from int to String to set in your textview::
counter[6].setText(countString);
}
else{
countString = "" +(++count[6]); //Convert from int to String to set in your textview::
counter[6].setText(countString);
}
}
});
}
public boolean onCreateOptionsMenu(Menu menu){ // What the MENU button does.
super.onCreateOptionsMenu(menu);
MenuInflater castle = getMenuInflater();
castle.inflate(R.menu.main_menu, menu);
return(true);
}
public boolean onOptionsItemSelected(MenuItem item){ // Opens Options of MENU.
switch(item.getItemId()){
case R.id.editcrap: startActivityForResult((new Intent("com.shuaib669.bunkrecord.EDITCRAP")), 1);
return(true);
}
return(false);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
super.onActivityResult(requestCode, resultCode, data);
switch(requestCode){
case 1: if(resultCode==Activity.RESULT_OK){
newText = data.getStringArrayExtra("com.shuaib669.bunkrecord.thetext");
newNum = data.getStringArrayExtra("com.shuaib669.bunkrecord.thenum");
try {
// open myfilename.txt for writing
DataOutputStream out = new DataOutputStream(openFileOutput(getFilesDir() + "/" + "subject.txt", Context.MODE_PRIVATE));
//newNum = data.getIntArrayExtra("com.shuaib669.thenum");
//for loop to setText in the TextViews of main.xml
for(int x=0;x<7;x++){
subject[x].setTextColor(Color.BLACK);
subject[x].setText(newText[x]);
// write the contents on mySettings to the file
out.writeUTF(newText[x]);
try{
no_of_classes[x]=Integer.parseInt(newNum[x]);
}
catch(Exception nfe){
nfe.printStackTrace();
}
// close the file
out.close();
}
}
catch (Exception e) {
Log.i("Data Input Sample", "I/O Error"); //do something if an Exception occurs.
}
}
break;
}
}
}
// editcrap.java：
package com.shuaib669.bunkrecord;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class editcrap extends Activity{
EditText sub[] = new EditText[7]; //list of subject text edit labels.
Button parambutton1; //OK buttons for edit list.
EditText num[] = new EditText[7]; //list of objects of total no. of classes bunked edit text labels. (boinkers i know)
String theText[] = new String[7];
String theNum[] = new String[7];
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.params);
sub[0] = (EditText) findViewById(R.id.peditText1); //pedittext is the parameter menu edit text label
num[0] = (EditText) findViewById(R.id.pnumText1); //EditText label for takin in total no. of classes for 1 subject
sub[1] = (EditText) findViewById(R.id.peditText2);
num[1] = (EditText) findViewById(R.id.pnumText2);
sub[2] = (EditText) findViewById(R.id.peditText3);
num[2] = (EditText) findViewById(R.id.pnumText3);
sub[3] = (EditText) findViewById(R.id.peditText4);
num[3] = (EditText) findViewById(R.id.pnumText4);
sub[4] = (EditText) findViewById(R.id.peditText5);
num[4] = (EditText) findViewById(R.id.pnumText5);
sub[5] = (EditText) findViewById(R.id.peditText6);
num[5] = (EditText) findViewById(R.id.pnumText6);
sub[6] = (EditText) findViewById(R.id.peditText7);
num[6] = (EditText) findViewById(R.id.pnumText7);
parambutton1 = (Button) findViewById(R.id.parambutton1); //pbutton1 is the ok button to accept the input.
parambutton1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
for(int x=0;x<7;x++){
theText[x] = sub[x].getText().toString();
theNum[x] = num[x].getText().toString();
//theNum[x] = Integer.parseInt(num[x].getText().toString());
}
Intent data = new Intent(editcrap.this, Sublist.class);
data.putExtra("com.shuaib669.bunkrecord.thetext", theText);
data.putExtra("com.shuaib669.bunkrecord.thenum", theNum);
setResult(Activity.RESULT_OK, data);
finish();
}
});
}
}
答案 0 :(得分：2)
使用共享首选项
public static final String PREFS_NAME = "MyPrefsFile";
private static final String PREF_USERNAME = "username";
private static final String PREF_PASSWORD = "password";
onCreate（）方法中的代码
EtUserName=(EditText) findViewById(R.id.EditText01);
EtPassword=(EditText) findViewById(R.id.EditText02);
这里你在editText中获得了Preferences值...（如果你以前有保存首选项）
SharedPreferences pref = getSharedPreferences(PREFS_NAME,MODE_PRIVATE);
String username = pref.getString(PREF_USERNAME, null);
String password = pref.getString(PREF_PASSWORD, null);
EtUserName.setText(username);
EtPassword.setText(password);
在复选框中的代码中单击事件...（在此处保存首选项）
String us,pa;
us=EtUserName.getText().toString();
pa=EtPassword.getText().toString();
SharedPreferences settings = getSharedPreferences(PREFS_NAME,MODE_PRIVATE);
getSharedPreferences(PREFS_NAME,MODE_PRIVATE)
.edit()
.putString(PREF_USERNAME, us)
.putString(PREF_PASSWORD, pa)
.commit();
了解更多信息click here。和here