我刚刚开始使用Android编程,这就是问题所在.
如何检查GridView中的项目是否已被点击?比如为Grid中的EACH项目分配一个布尔’clicked’并在每次单击该项时更改它的值.
目前我只是使用一个bool数组,所以如果我点击项目[x]它会切换bool [x]然后我会检查它是否为true / false并相应地修改项目,但必须有一个更简洁的方式这样做!
我的代码:
package com.example.mojrecnik;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.GridView;
import android.widget.AdapterView;
import android.widget.TextView;
import android.widget.Toast;
import android.support.v4.app.NavUtils;
public class Glavna extends Activity implements AdapterView.OnItemClickListener {
private static final int LENGTH_SHORT = 0;
GridView grid;
TextView tekst;
String[] izfajla = new String[200];
String[] izfajla2 = new String[200];
boolean[] kliknutmrs = new boolean[200];
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_glavna);
grid=(GridView)findViewById(R.id.grid);
grid.setAdapter(new MojAdapter());
grid.setOnItemClickListener(this);
//tekst=(TextView)findViewById(R.id.tekst);
citaFajl();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_glavna, menu);
return true;
}
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
TextView klik = (TextView)arg1.findViewById(R.id.gridtekst2);
if(kliknutmrs[arg2]) {
kliknutmrs[arg2]=!kliknutmrs[arg2];
klik.setText(izfajla[arg2]); }
else {
kliknutmrs[arg2]=!kliknutmrs[arg2];
klik.setText(izfajla2[arg2]); }
}
public void onNothingSelected(AdapterView<?> arg0) {
}
public void citaFajl() {
File kartica = Environment.getExternalStorageDirectory();
File fajl = new File(kartica, "reci.txt");
StringBuilder tekst = new StringBuilder();
int i=0;
try {
BufferedReader br = new BufferedReader(new FileReader(fajl));
String linija;
String[] prva;
while ((linija = br.readLine())!=null) {
prva = linija.split("-");
izfajla[i]=prva[0];
if(prva[1].length()>0)
izfajla2[i]=prva[1];
i ;
}
}
catch (IOException e) {
Toast greska = Toast.makeText(this, e.getMessage().toString(), LENGTH_SHORT);
greska.show();
}
}
private class MojAdapter extends ArrayAdapter {
public MojAdapter() {
super(Glavna.this, R.layout.gridvju, izfajla);
}
public View getView(int position, View convertView, ViewGroup parent) {
//vazno!! pravim vju od inflatera i vracam vju a ne convertvju!
View gridvju;
if(convertView==null) {
LayoutInflater inflater = getLayoutInflater();
gridvju = inflater.inflate(R.layout.gridvju, parent, false);
}
else
gridvju=convertView;
TextView tekst2 = (TextView)gridvju.findViewById(R.id.gridtekst2);
tekst2.setLines(2);
tekst2.setText(izfajla[position]);
return(gridvju);
}
}
}
和XML(主要):
<RelativeLayout xmlns:android="http://schemas./apk/res/android"
xmlns:tools="http://schemas./tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<!--
<TextView
android:id="@ id/tekst"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:textSize="20dp"
android:layout_below="@id/tekst" >
</TextView> -->
<GridView
android:id="@ id/grid"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:horizontalSpacing="@dimen/padding_medium"
android:numColumns="3"
android:stretchMode="columnWidth" >
</GridView>
</RelativeLayout>
和布局:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas./apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<TextView
xmlns:android="http://schemas./apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@ id/gridtekst2" />
</LinearLayout>
解决方法: 以下是我最终的工作方式.我创建了一个自定义类来包含显示的文本,并在其中添加了一个bool,所以现在gridview中的每个元素都有自己的“点击检查器”. 注意:这个程序简单地在onClick之间交替显示2个单词,如果你想尝试使用带有数据格式化’word1 – word2’的文本文件
码:
package com.example.mojrecnik;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.GridView;
import android.widget.AdapterView;
import android.widget.TextView;
import android.widget.Toast;
public class Glavna extends Activity implements AdapterView.OnItemClickListener {
private static final int LENGTH_LONG = 1;
GridView grid;
List<Rec> lReci = new ArrayList<Rec>(); //this is our list of data which contains text and bool check
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_glavna);
citaFajl();
grid=(GridView)findViewById(R.id.grid);
grid.setAdapter(new MojAdapter());
grid.setOnItemClickListener(this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_glavna, menu);
return true;
}
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
VjuHolder holder=(VjuHolder)arg1.getTag();
if(!lReci.get(arg2).clicked)
holder.text.setText(lReci.get(arg2).rec2);
else
holder.text.setText(lReci.get(arg2).rec1);
lReci.get(arg2).clicked = !lReci.get(arg2).clicked;
}
public void onNothingSelected(AdapterView<?> arg0) {
//////////////////////////////////////////
}
public void citaFajl() {
try {
BufferedReader br = new BufferedReader(new FileReader(new File(Environment.getExternalStorageDirectory(), "reci.txt")));
String[] reci = new String[2];
String linija;
Rec rec;
while ((linija = br.readLine()) != null) {
reci = linija.split("-"); //because data in my file is formatted 'word1 - word2', we separate them now so we can alternate between them
reci[1]=reci[1].trim();
rec = new Rec(reci[0], reci[1], false);
lReci.add(rec);
}
}
catch (IOException e) {
Toast.makeText(this, e.getMessage().toString(), LENGTH_LONG).show();
}
}
private class MojAdapter extends ArrayAdapter<String> {
public MojAdapter() {
super(Glavna.this, R.layout.gridvju);
}
public int getCount() {
return lReci.size(); //here we explicitly set the total number of grid elements so it doesn't go out of index range
}
public View getView(int position, View convertView, ViewGroup parent) {
VjuHolder holder;
if(convertView==null) {
LayoutInflater inflater = getLayoutInflater();
convertView = inflater.inflate(R.layout.gridvju, parent, false);
holder = new VjuHolder();
holder.text = (TextView)convertView.findViewById(R.id.gridtekst2);
convertView.setTag(holder); }
else
holder=(VjuHolder)convertView.getTag();
if(lReci.get(position).clicked) //check to make grid update according to the clicked state of our elements [when scrolling]
holder.text.setText(lReci.get(position).rec2);
else
holder.text.setText(lReci.get(position).rec1);
holder.text.setLines(2);
return(convertView);
}
}
}
//holder class
class VjuHolder {
TextView text;
}
//here we put the text to be displayed along with bool to check in which state is the clicked element
class Rec {
String rec1, rec2;
boolean clicked;
Rec(String rec, String druga, boolean klik) {
rec1 = rec;
rec2 = druga;
clicked = klik;
}
}
来源:https://www./content-4-297351.html
|