元素的ListView的每一行内preserve状态 [英] preserve state of elements inside listview's each row
本文介绍了元素的ListView的每一行内preserve状态的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我已经用打气筒充气每一行设计了一个ListView和我已经改变convertView的元素的颜色在他们的单击事件。但滚动列表之后的元素亏这些变化。我如何preserve自己的状态，并重新present他们？
和还有一个查询在我的脑海里，点击提交按钮的时候，我怎么能计算出没有被点击了哪个时listItems的总数是多少？
下面是我的code：
包scf.login;
进口android.app.Activity;
进口android.app.AlertDialog;
进口android.content.DialogInterface;
进口android.content.Intent;
进口android.graphics.Color;
进口android.os.Bundle;
进口android.view.LayoutInflater;
进口android.view.View;
进口android.view.ViewGroup;
进口android.view.View.OnClickListener;
进口android.widget.BaseAdapter;
进口android.widget.Button;
进口android.widget.ListView;
进口android.widget.TextView;
进口android.widget.Toast;公共类firstsubActivity扩展活动
{//变量声明
ListView的lvSubCat;
意向行动;
按钮btnBack，btnSubmit按钮，btnNext;
布尔提交= FALSE;
整数选中= 0;
的String []子状态= {，OK，，，，OK，，，警报，，，，经过， ，，OK，，，警报，};//定义上的点击监听器
android.view.View.OnClickListener lstnr =新android.view.View.OnClickListener（）
{ @覆盖
公共无效的onClick（视图v）
{
开关（v.getId（））{ 案例R.id.btnBack：
Toast.makeText（getApplicationContext（），后退按钮点击Toast.LENGTH_SHORT）.show（）;
打破;
案例R.id.btnSubmit：
如果（！提交）
{ checkcompletion（）; 如果（未选中大于0）
{
Toast.makeText（firstsubActivity.this，完整的precheking，Toast.LENGTH_LONG +未选中+灰色颜色突出显示的干预（S））.show（）;
}
其他
{
Toast.makeText（firstsubActivity.this，提交成功！，Toast.LENGTH_SHORT）.show（）;
提交= TRUE;
} }
其他
{
updatecofirmation（）;
}
打破;
案例R.id.btnNext：
如果（提交）
{
nextconfirmation（）;
}
其他
{
Toast.makeText（firstsubActivity.this，提交答案，Toast.LENGTH_SHORT）.show（）;
}
打破; }} 私人无效nextconfirmation（）
{
AlertDialog.Builder建设者=新AlertDialog.Builder（firstsubActivity.this）;
builder.setCancelable（假）;
builder.setTitle（确认消息）;
builder.setMessage（你要离开这个页面吗？）;
builder.setPositiveButton（是，新DialogInterface.OnClickListener（）{ @覆盖
公共无效的onClick（DialogInterface对话，诠释它）{
// TODO自动生成方法存根 意图动作=新意图（firstsubActivity.this，cat_subcatActivity.class）;
startActivity（动作）;
}
}）;
builder.setNegativeButton（否，新DialogInterface.OnClickListener（）{ @覆盖
公共无效的onClick（DialogInterface对话，诠释它）{
// TODO自动生成方法存根
Toast.makeText（firstsubActivity.this，不点击Toast.LENGTH_SHORT）.show（）; }
}）; builder.create（）显示（）。
}
私人无效updatecofirmation（）
{
AlertDialog.Builder builder2 =新AlertDialog.Builder（firstsubActivity.this）;
builder2.setCancelable（假）;
builder2.setTitle（确认消息）;
builder2.setMessage（你要更新的答案？）;
builder2.setPositiveButton（是，新DialogInterface.OnClickListener（）{ @覆盖
公共无效的onClick（DialogInterface对话，诠释它）{
// TODO自动生成方法存根
提交= FALSE;
btnSubmit.performClick（）;
}
}）;
builder2.setNegativeButton（否，新DialogInterface.OnClickListener（）{ @覆盖
公共无效的onClick（DialogInterface对话，诠释它）{
// TODO自动生成方法存根
Toast.makeText（firstsubActivity.this，不点击Toast.LENGTH_SHORT）.show（）; }
}）; builder2.create（）显示（）。
}
私人无效checkcompletion（）
{
未选中= subStatus.length;
尝试
{
对于（整数j = 0; J＆LT; subStatus.length; J ++）
{
// CONFUSED
} }
赶上（例外五）{
e.printStackTrace（）;
}
最后
{ } }
};@覆盖
保护无效的onCreate（捆绑savedInstanceState）
{
// TODO自动生成方法存根
super.onCreate（savedInstanceState）;
的setContentView（R.layout.firstsub）; //捆绑
lvSubCat =（ListView控件）findViewById（R.id.lvSubCat）;
btnBack =（按钮）findViewById（R.id.btnBack）;
btnSubmit按钮=（按钮）findViewById（R.id.btnSubmit）;
btnNext =（按钮）findViewById（R.id.btnNext）; //设置监听器
btnBack.setOnClickListener（lstnr）;
btnSubmit.setOnClickListener（lstnr）;
btnNext.setOnClickListener（lstnr）;
//子类别的数据，并从数据库及其状态
的String [] = SUBCAT {\"zero\",\"first\",\"second\",\"third\",\"forth\",\"fifth\",\"sixth\",\"seventh\",\"eighth\",\"ninth\",\"tenth\",\"eleventh\",\"twelfth\",\"thirteenth\",\"forteenth\",\"fifteenth\",\"sixteenth\",\"seventeenth\",\"eighteenth\",\"ninteenth\"};
的String []子状态= {，OK，，，，OK，，，警报，，，，经过， ，，OK，，，警报，};
/ *
对于（整数i = 0; I＆LT; subStatus.length;我++）
{
设置每个子类别的状态
}
* / //设置适配器和结合衔接的意见
MySimpleAdapter适配器1 =新MySimpleAdapter（这一点，SUBCAT）;
lvSubCat.setAdapter（适配器1）;
}//定义firstsubActivity类内部定制MySimpleAdapter类
公共类MySimpleAdapter延伸BaseAdapter
{
私人最终活动范围内;
私人最终的String [] SUBCAT;
公共MySimpleAdapter（Activity上下文，字符串[] SUBCAT）
{
超（）;
this.context =背景;
this.subCat = SUBCAT;
}
/ *
保护类viewHolder
{
TextView的tvOk;
按钮btnChecked，btnAlert;
}
* /
@覆盖
公众诠释的getCount（）{
// TODO自动生成方法存根
返回subCat.length;
}
@覆盖
公共对象的getItem（INT为arg0）{
// TODO自动生成方法存根
返回null;
}
@覆盖
众长getItemId（INT为arg0）{
// TODO自动生成方法存根
返回0;
} @覆盖
公共查看getView（最终诠释的立场，观点convertView，父母的ViewGroup）
{//最后viewHolder持有人=新viewHolder（）; //膨胀
LayoutInflater吹气= context.getLayoutInflater（）;
convertView = inflater.inflate（R.layout.lstinfl，NULL）;
//捆绑
最终的TextView tvOk =（TextView中）convertView.findViewById（R.id.tvOk）;
最终按钮btnChecked =（按钮）convertView.findViewById（R.id.btnChecked）;
最终按钮btnAlert =（按钮）convertView.findViewById（R.id.btnAlert）; //插入子
tvOk.setText（SUBCAT [位置]）; //重新$ P $根据自己的状态psenting小类
尝试
{
对于（整数k = 0; K＆LT; subStatus.length; k ++）
{
// CONFUSED } }
赶上（例外五）{
// TODO：处理异常
}
最后
{ } //监听器来改变颜色和状态
tvOk.setOnClickListener（新OnClickListener（）{ @覆盖
公共无效的onClick（查看为arg0）{
tvOk.setClickable（假）;
btnChecked.setClickable（真）;
btnAlert.setClickable（真）;
tvOk.setBackgroundColor（Color.GREEN）;
btnChecked.setBackgroundColor（Color.WHITE）;
btnAlert.setBackgroundColor（Color.WHITE）;
子状态[位置] =确定;
}
}）; btnChecked.setOnClickListener（新OnClickListener（）{ @覆盖
公共无效的onClick（视图v）{
tvOk.setClickable（真）;
btnChecked.setClickable（假）;
btnAlert.setClickable（真）;
tvOk.setBackgroundColor（Color.BLACK）;
btnChecked.setBackgroundColor（Color.YELLOW）;
btnAlert.setBackgroundColor（Color.WHITE）;
子状态[位置] =选中;
//动作=新意图（getApplicationContext（），subdescActivity.class）;
// startActivity（动作）; }
}）; btnAlert.setOnClickListener（新OnClickListener（）{ @覆盖
公共无效的onClick（视图v）{
tvOk.setClickable（真）;
btnChecked.setClickable（真）;
btnAlert.setClickable（假）;
tvOk.setBackgroundColor（Color.BLACK）;
btnChecked.setBackgroundColor（Color.WHITE）;
btnAlert.setBackgroundColor（Color.RED）;
子状态[位置] =警报;
//动作=新意图（getApplicationContext（），subdescActivity.class）;
// startActivity（动作）;
}
}）;
返回convertView;
}}
}
解决方案
好吧，你节省了阵列两种状态（文本和状态），所以至少这部分是好的。现在，你需要检查状态[] 在getView（）来设置根据它的按钮正确的外观和感觉，是这样的：
如果（子状态[位置] .equals（OK））{
tvOk.setClickable（假）;
btnChecked.setClickable（真）;
btnAlert.setClickable（真）;
tvOk.setBackgroundColor（Color.GREEN）;
btnChecked.setBackgroundColor（Color.WHITE）;
btnAlert.setBackgroundColor（Color.WHITE）;
子状态[位置] =确定;
}
....
然后当你提交你可以通过这些状态的项目，看看有什么被点击或没有。
I have designed a listview by inflating each row using inflater and I have changed color of convertView's elements on their click events. But after scrolling the list the elements loss these changes. How can I "preserve" their state and represent them?
And there is one more query in my mind, when clicking the submit button, how can I calculate the total number of "listitems" which had not been clicked?
Here is my code:
package scf.login;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class firstsubActivity extends Activity
{
//variable declaration
ListView lvSubCat;
Intent action;
Button btnBack,btnSubmit,btnNext;
Boolean submission=false;
Integer unchecked=0;
String[] subStatus = {"","Ok","","","","Ok","","","Alert","","","","Checked","","","Ok","","","Alert",""};
// defining on click listener
android.view.View.OnClickListener lstnr = new android.view.View.OnClickListener()
{
@Override
public void onClick(View v)
{
switch (v.getId()) {
case R.id.btnBack:
Toast.makeText(getApplicationContext(), "Back button clicked", Toast.LENGTH_SHORT).show();
break;
case R.id.btnSubmit:
if(!submission)
{
checkcompletion();
if(unchecked>0)
{
Toast.makeText(firstsubActivity.this, "Complete the precheking of "+unchecked+" intervention(s) highlighted by Gray colour", Toast.LENGTH_LONG).show();
}
else
{
Toast.makeText(firstsubActivity.this,"Successfully submitted !!",Toast.LENGTH_SHORT).show();
submission=true;
}
}
else
{
updatecofirmation();
}
break;
case R.id.btnNext:
if(submission)
{
nextconfirmation();
}
else
{
Toast.makeText(firstsubActivity.this,"Submit the answers",Toast.LENGTH_SHORT).show();
}
break;
}
}
private void nextconfirmation()
{
AlertDialog.Builder builder = new AlertDialog.Builder(firstsubActivity.this);
builder.setCancelable(false);
builder.setTitle("Confirmation message");
builder.setMessage("Do you want to leave this page ?");
builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
Intent action = new Intent(firstsubActivity.this,cat_subcatActivity.class);
startActivity(action);
}
});
builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
Toast.makeText(firstsubActivity.this, "No clicked", Toast.LENGTH_SHORT).show();
}
});
builder.create().show();
}
private void updatecofirmation()
{
AlertDialog.Builder builder2 = new AlertDialog.Builder(firstsubActivity.this);
builder2.setCancelable(false);
builder2.setTitle("Confirmation message");
builder2.setMessage("Do you want to update answers ?");
builder2.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
submission=false;
btnSubmit.performClick();
}
});
builder2.setNegativeButton("No", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
Toast.makeText(firstsubActivity.this, "No clicked", Toast.LENGTH_SHORT).show();
}
});
builder2.create().show();
}
private void checkcompletion()
{
unchecked=subStatus.length;
try
{
for(Integer j=0;j<subStatus.length;j++)
{
// CONFUSED
}
}
catch (Exception e) {
e.printStackTrace();
}
finally
{
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState)
{
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.firstsub);
//Binding
lvSubCat = (ListView)findViewById(R.id.lvSubCat);
btnBack = (Button)findViewById(R.id.btnBack);
btnSubmit=(Button)findViewById(R.id.btnSubmit);
btnNext = (Button)findViewById(R.id.btnNext);
//setting listeners
btnBack.setOnClickListener(lstnr);
btnSubmit.setOnClickListener(lstnr);
btnNext.setOnClickListener(lstnr);
//data of subcategories and their status from database
String[] subCat = {"zero","first","second","third","forth","fifth","sixth","seventh","eighth","ninth","tenth","eleventh","twelfth","thirteenth","forteenth","fifteenth","sixteenth","seventeenth","eighteenth","ninteenth"};
String[] subStatus = {"","Ok","","","","Ok","","","Alert","","","","Checked","","","Ok","","","Alert",""};
/*
for(Integer i=0;i<subStatus.length;i++)
{
set the status of each subcategory
}
*/
//setting adapter and binding adapter to the views
MySimpleAdapter adapter1 = new MySimpleAdapter(this,subCat);
lvSubCat.setAdapter(adapter1);
}
//defining customised MySimpleAdapter class inside firstsubActivity class
public class MySimpleAdapter extends BaseAdapter
{
private final Activity context;
private final String[] subCat;
public MySimpleAdapter(Activity context, String[] subCat)
{
super();
this.context = context;
this.subCat = subCat;
}
/*
protected class viewHolder
{
TextView tvOk;
Button btnChecked,btnAlert;
}
*/
@Override
public int getCount() {
// TODO Auto-generated method stub
return subCat.length;
}
@Override
public Object getItem(int arg0) {
// TODO Auto-generated method stub
return null;
}
@Override
public long getItemId(int arg0) {
// TODO Auto-generated method stub
return 0;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent)
{
// final viewHolder holder = new viewHolder();
//inflating
LayoutInflater inflater = context.getLayoutInflater();
convertView = inflater.inflate(R.layout.lstinfl,null);
//binding
final TextView tvOk=(TextView)convertView.findViewById(R.id.tvOk);
final Button btnChecked=(Button)convertView.findViewById(R.id.btnChecked);
final Button btnAlert=(Button)convertView.findViewById(R.id.btnAlert);
//inserting subcategories
tvOk.setText(subCat[position]);
//representing subcategories according to their status
try
{
for(Integer k=0;k<subStatus.length;k++)
{
// CONFUSED
}
}
catch (Exception e) {
// TODO: handle exception
}
finally
{
}
//listeners to change the Color and Status
tvOk.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
tvOk.setClickable(false);
btnChecked.setClickable(true);
btnAlert.setClickable(true);
tvOk.setBackgroundColor(Color.GREEN);
btnChecked.setBackgroundColor(Color.WHITE);
btnAlert.setBackgroundColor(Color.WHITE);
subStatus[position]="Ok";
}
});
btnChecked.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
tvOk.setClickable(true);
btnChecked.setClickable(false);
btnAlert.setClickable(true);
tvOk.setBackgroundColor(Color.BLACK);
btnChecked.setBackgroundColor(Color.YELLOW);
btnAlert.setBackgroundColor(Color.WHITE);
subStatus[position]="Checked";
// action = new Intent(getApplicationContext(), subdescActivity.class);
// startActivity(action);
}
});
btnAlert.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
tvOk.setClickable(true);
btnChecked.setClickable(true);
btnAlert.setClickable(false);
tvOk.setBackgroundColor(Color.BLACK);
btnChecked.setBackgroundColor(Color.WHITE);
btnAlert.setBackgroundColor(Color.RED);
subStatus[position]="Alert";
// action = new Intent(getApplicationContext(), subdescActivity.class);
// startActivity(action);
}
});
return convertView;
}
}
}
解决方案
Well, you're saving both states (text and status) in arrays, so at least that part is good. Now you need to check the states[] in your getView() to set the correct look and feel of your buttons according to it, something like:
if (subStatus[position].equals("Ok")) {
tvOk.setClickable(false);
btnChecked.setClickable(true);
btnAlert.setClickable(true);
tvOk.setBackgroundColor(Color.GREEN);
btnChecked.setBackgroundColor(Color.WHITE);
btnAlert.setBackgroundColor(Color.WHITE);
subStatus[position]="Ok";
}
....
Then when you submit you can go through these status items and see what was clicked or not.
这篇关于元素的ListView的每一行内preserve状态的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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