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java - 如何在此代码中实现 OnItemClickListener?

转载 作者:行者123 更新时间:2023-11-29 07:40:50 29 4
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我想在此 ListView 中实现 OnItemClickListener ,但是当我为此添加代码时,即使没有错误,我的应用程序也无法运行。当我单击 Listview 项目时,它会自动关闭。请帮助我,我是 Android 的初学者。我在这里添加我的整个代码。我正在做蓝牙设备连接代码。

MainActivity.java

    import java.util.ArrayList;
import java.util.Set;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;

import android.graphics.Color;
import android.os.Bundle;
import android.view.View;

import android.app.Activity;
import android.app.ProgressDialog;

import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;

public class MainActivity extends Activity {
private TextView mStatusTv;
private Button mActivateBtn;
private Button mPairedBtn;
private Button mScanBtn;
private Button ledBtn;
private ProgressDialog mProgressDlg;

private ArrayList<BluetoothDevice> mDeviceList = new ArrayList<BluetoothDevice>();

private BluetoothAdapter mBluetoothAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

mStatusTv = (TextView) findViewById(R.id.tv_status);
mActivateBtn = (Button) findViewById(R.id.btn_enable);
mPairedBtn = (Button) findViewById(R.id.btn_view_paired);
mScanBtn = (Button) findViewById(R.id.btn_scan);
ledBtn = (Button) findViewById(R.id.led);
ledBtn.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent i=new Intent(getApplicationContext(),Ledbuttons.class);
startActivity(i);
}
});

mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

mProgressDlg = new ProgressDialog(this);

mProgressDlg.setMessage("Scanning...");
mProgressDlg.setCancelable(false);
mProgressDlg.setButton(DialogInterface.BUTTON_NEGATIVE, "Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();

mBluetoothAdapter.cancelDiscovery();
}
});

if (mBluetoothAdapter == null) {
showUnsupported();
} else {
mPairedBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();

if (pairedDevices == null || pairedDevices.size() == 0) {
showToast("No Paired Devices Found");
} else {
ArrayList<BluetoothDevice> list = new ArrayList<BluetoothDevice>();

list.addAll(pairedDevices);

Intent intent = new Intent(MainActivity.this, DeviceListActivity.class);

intent.putParcelableArrayListExtra("device.list", list);

startActivity(intent);
}
}
});

mScanBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
mBluetoothAdapter.startDiscovery();
}
});

mActivateBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mBluetoothAdapter.isEnabled()) {
mBluetoothAdapter.disable();

showDisabled();
} else {
Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);

startActivityForResult(intent, 1000);
}
}
});

if (mBluetoothAdapter.isEnabled()) {
showEnabled();
} else {
showDisabled();
}
}

IntentFilter filter = new IntentFilter();

filter.addAction(BluetoothAdapter.ACTION_STATE_CHANGED);
filter.addAction(BluetoothDevice.ACTION_FOUND);
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);

registerReceiver(mReceiver, filter);
}


@Override
public void onPause() {
if (mBluetoothAdapter != null) {
if (mBluetoothAdapter.isDiscovering()) {
mBluetoothAdapter.cancelDiscovery();
}
}

super.onPause();
}

@Override
public void onDestroy() {
unregisterReceiver(mReceiver);

super.onDestroy();
}

private void showEnabled() {
mStatusTv.setText("Bluetooth is On");
mStatusTv.setTextColor(Color.BLUE);

mActivateBtn.setText("Disable");
mActivateBtn.setEnabled(true);

mPairedBtn.setEnabled(true);
mScanBtn.setEnabled(true);
ledBtn.setEnabled(true);
}

private void showDisabled() {
mStatusTv.setText("Bluetooth is Off");
mStatusTv.setTextColor(Color.RED);

mActivateBtn.setText("Enable");
mActivateBtn.setEnabled(true);

mPairedBtn.setEnabled(false);
mScanBtn.setEnabled(false);
ledBtn.setEnabled(false);
}

private void showUnsupported() {
mStatusTv.setText("Bluetooth is unsupported by this device");

mActivateBtn.setText("Enable");
mActivateBtn.setEnabled(false);

mPairedBtn.setEnabled(false);
mScanBtn.setEnabled(false);
}

private void showToast(String message) {
Toast.makeText(getApplicationContext(), message, Toast.LENGTH_SHORT).show();
}

private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();

if (BluetoothAdapter.ACTION_STATE_CHANGED.equals(action)) {
final int state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, BluetoothAdapter.ERROR);

if (state == BluetoothAdapter.STATE_ON) {
showToast("Enabled");

showEnabled();
}
} else if (BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)) {
mDeviceList = new ArrayList<BluetoothDevice>();

mProgressDlg.show();
} else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
mProgressDlg.dismiss();

Intent newIntent = new Intent(MainActivity.this, DeviceListActivity.class);

newIntent.putParcelableArrayListExtra("device.list", mDeviceList);

startActivity(newIntent);
} else if (BluetoothDevice.ACTION_FOUND.equals(action)) {
BluetoothDevice device = (BluetoothDevice) intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);

mDeviceList.add(device);

showToast("Found device " + device.getName());
}
}
};

DeviceListActivity.java

    import java.lang.reflect.Method;
import java.util.ArrayList;

import android.app.Activity;
import android.bluetooth.BluetoothDevice;
import android.os.Bundle;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;

import android.view.View;
import android.widget.ListView;
import android.widget.Toast;


public class DeviceListActivity extends Activity {
private ListView mListView;
private DeviceListAdapter mAdapter;
private ArrayList<BluetoothDevice> mDeviceList;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

mDeviceList = getIntent().getExtras().getParcelableArrayList("device.list");

mListView = (ListView) findViewById(R.id.lv_paired);

mAdapter = new DeviceListAdapter(this);

mAdapter.setData(mDeviceList);
mAdapter.setListener(new DeviceListAdapter.OnPairButtonClickListener() {
@Override
public void onPairButtonClick(int position) {
BluetoothDevice device = mDeviceList.get(position);

if (device.getBondState() == BluetoothDevice.BOND_BONDED) {
unpairDevice(device);
} else {
showToast("Pairing...");

pairDevice(device);
}
}
});

mListView.setAdapter(mAdapter);

registerReceiver(mPairReceiver, new IntentFilter(BluetoothDevice.ACTION_BOND_STATE_CHANGED));
}

@Override
public void onDestroy() {
unregisterReceiver(mPairReceiver);

super.onDestroy();
}


private void showToast(String message) {
Toast.makeText(getApplicationContext(), message, Toast.LENGTH_SHORT).show();
}

private void pairDevice(BluetoothDevice device) {
try {
Method method = device.getClass().getMethod("createBond", (Class[]) null);
method.invoke(device, (Object[]) null);
} catch (Exception e) {
e.printStackTrace();
}
}

private void unpairDevice(BluetoothDevice device) {
try {
Method method = device.getClass().getMethod("removeBond", (Class[]) null);
method.invoke(device, (Object[]) null);

} catch (Exception e) {
e.printStackTrace();
}
}

private final BroadcastReceiver mPairReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();

if (BluetoothDevice.ACTION_BOND_STATE_CHANGED.equals(action)) {
final int state = intent.getIntExtra(BluetoothDevice.EXTRA_BOND_STATE, BluetoothDevice.ERROR);
final int prevState = intent.getIntExtra(BluetoothDevice.EXTRA_PREVIOUS_BOND_STATE, BluetoothDevice.ERROR);

if (state == BluetoothDevice.BOND_BONDED && prevState == BluetoothDevice.BOND_BONDING) {
showToast("Paired");
} else if (state == BluetoothDevice.BOND_NONE && prevState == BluetoothDevice.BOND_BONDED){
showToast("Unpaired");
}

mAdapter.notifyDataSetChanged();
}
}
};

}

DeviceListAdapter.java

    import java.util.List;

import android.bluetooth.BluetoothDevice;
import android.content.Context;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.TextView;


public class DeviceListAdapter extends BaseAdapter{
private LayoutInflater mInflater;
private List<BluetoothDevice> mData;
private OnPairButtonClickListener mListener;

public DeviceListAdapter(Context context) {
mInflater = LayoutInflater.from(context);
}

public void setData(List<BluetoothDevice> data) {
mData = data;
}

public void setListener(OnPairButtonClickListener listener) {
mListener = listener;
}

public int getCount() {
return (mData == null) ? 0 : mData.size();
}

public Object getItem(int position) {
return null;
}

public long getItemId(int position) {
return position;
}

public View getView(final int position, View convertView, ViewGroup parent) {
ViewHolder holder;

if (convertView == null) {
convertView = mInflater.inflate(R.layout.list_item_device, null);

holder = new ViewHolder();

holder.nameTv = (TextView) convertView.findViewById(R.id.tv_name);
holder.addressTv = (TextView) convertView.findViewById(R.id.tv_address);
holder.pairBtn = (Button) convertView.findViewById(R.id.btn_pair);

convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}

BluetoothDevice device = mData.get(position);

holder.nameTv.setText(device.getName());
holder.addressTv.setText(device.getAddress());
holder.pairBtn.setText((device.getBondState() == BluetoothDevice.BOND_BONDED) ? "Unpair" : "Pair");
holder.pairBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mListener != null) {
mListener.onPairButtonClick(position);
}
}
});

return convertView;
}

static class ViewHolder {
TextView nameTv;
TextView addressTv;
TextView pairBtn;
}

public interface OnPairButtonClickListener {
public abstract void onPairButtonClick(int position);
}
}

activity_main.xml

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#060606"
android:orientation="vertical"
android:padding="@dimen/activity_vertical_margin" >

<TextView
android:id="@+id/tv_status"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:text="@string/text_bluetooth_off"
android:textColor="#ff0000"
android:textSize="17sp" />

<Button
android:id="@+id/btn_enable"
android:layout_width="match_parent"
android:layout_height="33dp"
android:layout_marginTop="@dimen/activity_vertical_margin"
android:background="#585858"
android:text="@string/text_enable" />

<Button
android:id="@+id/btn_view_paired"
android:layout_width="match_parent"
android:layout_height="33dp"
android:layout_marginTop="@dimen/activity_vertical_margin"
android:background="#585858"
android:enabled="false"
android:text="@string/text_view_paired"
android:textColor="#FFFFFF" />

<Button
android:id="@+id/btn_scan"
android:layout_width="match_parent"
android:layout_height="33dp"
android:layout_marginTop="@dimen/activity_vertical_margin"
android:background="#585858"
android:enabled="false"
android:text="@string/text_scan_devices"
android:textColor="#FFFFFF" />

<Button
android:id="@+id/led"
android:layout_width="match_parent"
android:layout_height="33dp"
android:layout_marginTop="@dimen/activity_vertical_margin"
android:background="#585858"
android:enabled="false"
android:text="LEDS"
android:textColor="#FFFFFF" />

<TextView
android:id="@+id/TextView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:text="List Of Devices"
android:textColor="#ff0000"
android:textSize="15sp" />

<ScrollView
android:id="@+id/scrollView1"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</ScrollView>

<ListView
android:id="@+id/lv_paired"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</ListView>

</LinearLayout>

list_item_device.xml

    <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingTop="5dp"
android:paddingBottom="5dp">

<Button
android:id="@+id/btn_pair"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:text="Pair"
android:textColor="#ff4444" />

<TextView
android:id="@+id/tv_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignTop="@+id/btn_pair"
android:layout_toLeftOf="@+id/btn_pair"
android:text="Galaxy Nexus"
android:textColor="#99cc00"
android:textSize="16sp" />

<TextView
android:id="@+id/tv_address"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/btn_pair"
android:layout_alignParentLeft="true"
android:layout_toLeftOf="@+id/btn_pair"
android:text="000000000"
android:textColor="#ffbd21" />

</RelativeLayout>

我没有解决的问题是

  1. 当我将 onItemclicklistener 添加到 ListView 时,应用程序无法运行。

  2. 蓝牙搜索结果填充了相同的设备名称。

  3. 查看配对设备后我无法访问按钮,并且扫描的设备(看起来相同的布局正在弹出到屏幕上)。

    任何人都请帮助我解决这些问题。

提前致谢。

最佳答案

你可以这样做 -

mListView.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {

Toast.makeText(getApplicationContext(), " ITEM CLICKED POSITION = "+String.valueOf(position), Toast.LENGTH_SHORT).show();
}
});

关于java - 如何在此代码中实现 OnItemClickListener?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/30410732/

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