我不能在我的复选框中使用OnClicListener。当我使用OnClicListener
时，我的应用程序崩溃了SDCardImagesActivity.java
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Color;
import android.net.Uri;
import android.net.wifi.WifiManager;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.Toast;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FilenameFilter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
public class SDCardImagesActivity extends Activity {
private ImageAdapter imageAdapter;
private ArrayList<File> imagenesSeleccionadas;
private File[] imagenes;
private static final String DIRECCION_IP = "http://192.168.1.127";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sdcard_images);
WifiManager wifiManager ;
wifiManager (WifiManager)this.getSystemService(Context.WIFI_SERVICE);
wifiManager.setWifiEnabled(true);
File directorios;
directorios = Environment.getExternalStorageDirectory();
directorios = getFolder(directorios, "WhatsApp");
directorios = getFolder(directorios, "Media");
directorios = getFolder(directorios, "WhatsApp Images");
imagenes = directorios.listFiles(new FilenameFilter() {
@Override
public boolean accept(File dir, String filename) {
return filename.endsWith(".jpg");
}
});
directorios = null;
imagenesSeleccionadas = new ArrayList<>();
final GridView gridView = (GridView) findViewById(R.id.Grid);
Button transfer = (Button) findViewById(R.id.btnTransfer);
final CheckBox seleccionarTodo=(CheckBox)findViewById(R.id.checkbox);
if (imagenes != null){
imageAdapter = new ImageAdapter(SDCardImagesActivity.this,imagenes);
gridView.setAdapter(imageAdapter);
gridView.setChoiceMode(GridView.CHOICE_MODE_MULTIPLE);
gridView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
File file = imagenes[position];
if (imagenesSeleccionadas.contains(file)) {
imagenesSeleccionadas.remove(file);
imageAdapter.getView(position, view, parent).setBackgroundColor(Color.WHITE);
} else {
imagenesSeleccionadas.add(file);
imageAdapter.getView(position, view, parent).setBackgroundColor(Color.BLUE);
}
file = null;
}
});
seleccionarTodo.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (seleccionarTodo.isChecked()) {
seleccionarTodo.setText("Seleccionar Todo");
Toast.makeText(SDCardImagesActivity.this, "Desmarcado", Toast.LENGTH_SHORT).show();
for (int i = 0; i < imageAdapter.getCount(); i++) {
if (!gridView.isItemChecked(i)) {
gridView.setItemChecked(i, true);
imagenesSeleccionadas.add((File) imageAdapter.getItem(i));
}
}
} else {
seleccionarTodo.setText("Deseleccionar Todo");
Toast.makeText(SDCardImagesActivity.this, "Marcado", Toast.LENGTH_SHORT).show();
for (int i = 0; i < imageAdapter.getCount(); i++) {
if (gridView.isItemChecked(i)) {
gridView.setItemChecked(i, false);
imagenesSeleccionadas.clear();
}
}
}
}
});
transfer.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (!imagenesSeleccionadas.isEmpty()) {
Intent service = new Intent(getApplicationContext(), HttpSendingService.class);
try
{
OutputStreamWriter fout = new OutputStreamWriter(openFileOutput(".config", Context.MODE_PRIVATE));
fout.write(DIRECCION_IP);
fout.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
for (File f : imagenesSeleccionadas){
service.setData(Uri.parse(f.getAbsolutePath()));
getApplicationContext().startService(service);
}
} else {
Toast.makeText(SDCardImagesActivity.this, "Ninguna imagen seleccionada", Toast.LENGTH_SHORT).show();
}
}
});
}else{
Toast.makeText(SDCardImagesActivity.this, "Images array is null", Toast.LENGTH_SHORT).show();
}
}
private File getFolder(File file, String nextFolderName){
File nextFolder = null;
File[] fileList;
if (file.isDirectory()){
fileList = file.listFiles();
for (File f:fileList){
if (f.isDirectory()){
if (f.getName().equals(nextFolderName)){
nextFolder = f;
}
}
}
}
return nextFolder;
}
}
清单：
<?xml version="1.0" encoding="utf-8"?>
<uses-permission android:name="android.permission.MANAGE_DOCUMENTS"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".SDCardImagesActivity"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:name=".HttpSendingService"
android:exported="false"/>
</application>
最后，activity.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:tools="http://schemas.android.com/tools"
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/layaut"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".MainActivity">
<GridView xmlns:android="http://schemas.android.com/apk/res/android"
android:clickable="true"
android:id="@+id/Grid"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="2dp"
android:verticalSpacing="3dp"
android:horizontalSpacing="3dp"
android:numColumns="3"
android:stretchMode="columnWidth"
android:gravity="center"
android:layout_above="@+id/btnTransfer"
android:drawSelectorOnTop="true"
android:layout_below="@+id/checkBox" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Trasmitir Imágenes"
android:id="@+id/btnTransfer"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:capitalize="words"
android:clickable="true"/>
<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Seleccionar Todo"
android:id="@+id/checkBox"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:clickable="true"/>
</RelativeLayout>
多数民众赞成。那么，为什么我不能使用我的复选框没有错误或应用程序崩溃？
答案 0 :(得分：2)
查看您的XML。你应该发布你的LogCat，但我敢打赌你得到一个与复选框相关的NullPointerException。
<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Seleccionar Todo"
android:id="@+id/checkBox"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:clickable="true"/>
请注意android:id="@+id/checkBox" checkBox的大写字母为“B”。
在您的代码中，您正在寻找带有小写“b”的“复选框”。
final CheckBox seleccionarTodo=(CheckBox)findViewById(R.id.checkbox);
看起来应该是这样的
final CheckBox seleccionarTodo=(CheckBox)findViewById(R.id.checkBox);