android 常用的代码-白红宇

android 常用的代码

阅读量：501 次

发布时间：2019-03-07

本文共 4311 字，大约阅读时间需要 14 分钟。

在Android开发中，随时需要一些常用的代码示例以备查找。以下是一些常见的代码片段，涵盖了进制转换、文件操作、权限管理等多个方面。

1. 进制转换

1.1 二进制转10进制

String two = "0001";
int ten = Integer.parseInt(two, 2);

1.2 10进制转二进制

int ten = 10;
String two = Integer.toBinaryString(ten);

1.3 10进制转16进制

int ten = 10;
String sixteen = Integer.toHexString(ten);

1.4 16进制转10进制

String sixteen = "A6";
int ten = Integer.parseInt(sixteen, 16);

1.5 二进制转16进制

String two = "0001";
int ten = Integer.parseInt(two, 2);
String sixteen = Integer.toHexString(ten);

1.6 16进制转二进制

String sixteen = "A6";
int ten = Integer.parseInt(sixteen, 16);
String two = Integer.toBinaryString(ten);

1.7 16进制高位补0

public static String ten2Hex2(int num) {
    String strHex2 = String.format("%08x", num).toUpperCase();
    return strHex2;
}

1.8 十进制数据转换为16进制并高位在前，低位在后

public static String decToHex(int dec) {
    String hex = "";
    while (dec != 0) {
        String h = Integer.toString(dec & 0xff, 16);
        if ((h.length() & 1) == 1) {
            h = '0' + h;
        }
        hex = hex + h;
        dec = dec >> 8;
    }
    return hex;
}

2. 睡眠处理

new Handler().postDelayed(new Runnable() {
    @Override
    public void run() {
        sendCommands(2, null); // 一秒后执行握手动作
    }
}, 1000);

3. 调用浏览器

Uri uri = Uri.parse("http://www.066810.com");
Intent it = new Intent(Intent.ACTION_VIEW, uri);
startActivity(it);

4. 广播接收

public class getBroadcast extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        if (Intent.ACTION_PACKAGE_ADDED.equals(intent.getAction())) {
            Toast.makeText(context, "有应用被添加", Toast.LENGTH_LONG).show();
        } else if (Intent.ACTION_PACKAGE_REMOVED.equals(intent.getAction())) {
            Toast.makeText(context, "有应用被删除", Toast.LENGTH_LONG).show();
        } else if (Intent.ACTION_PACKAGE_REPLACED.equals(intent.getAction())) {
            Toast.makeText(context, "有应用被替换", Toast.LENGTH_LONG).show();
        } else if (Intent.ACTION_CAMERA_BUTTON.equals(intent.getAction())) {
            Toast.makeText(context, "按键", Toast.LENGTH_LONG).show();
        }
    }
}

5. Toast使用

public void DisplayToast(String str) {
    Toast.makeText(this, str, Toast.LENGTH_SHORT).show();
}

6. 文件操作

6.1 写文件

public void writefile(String str, String path) {
    File file;
    FileOutputStream out;
    try {
        file = new File(path);
        file.createNewFile();
        out = new FileOutputStream(file);
        String infoToWrite = str;
        out.write(infoToWrite.getBytes());
        out.close();
    } catch (IOException e) {
        DisplayToast(e.toString());
    }
}

6.2 读文件

public String getinfo(String path) {
    File file;
    String str = "";
    FileInputStream in;
    try {
        file = new File(path);
        in = new FileInputStream(file);
        int length = (int) file.length();
        byte[] temp = new byte[length];
        in.read(temp, 0, length);
        str = EncodingUtils.getString(temp, TEXT_ENCODING);
        in.close();
    } catch (IOException e) {
        DisplayToast(e.toString());
    }
    return str;
}

7. 打电话

public static void call(Context context, String phoneNumber) {
    context.startActivity(new Intent(Intent.ACTION_CALL, Uri.parse("tel:" + phoneNumber)));
}

8. 跳转拨号界面

public static void callDial(Context context, String phoneNumber) {
    context.startActivity(new Intent(Intent.ACTION_DIAL, Uri.parse("tel:" + phoneNumber)));
}

9. 发送短信

public static void sendSms(Context context, String phoneNumber, String content) {
    Uri uri = Uri.parse("smsto:" + (TextUtils.isEmpty(phoneNumber) ? "" : phoneNumber));
    Intent intent = new Intent(Intent.ACTION_SENDTO, uri);
    intent.putExtra("sms_body", TextUtils.isEmpty(content) ? "" : content);
    context.startActivity(intent);
}

10. 唤醒屏幕并解锁

public static void wakeUpAndUnlock(Context context) {
    KeyguardManager km = (KeyguardManager) context.getSystemService(Context.KEYGUARD_SERVICE);
    KeyguardManager.KeyguardLock kl = km.newKeyguardLock("unLock");
    kl.disableKeyguard();
    PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
    PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.ACQUIRE_CAUSES_WAKEUP | PowerManager.SCREEN_DIM_WAKE_LOCK, "bright");
    wl.acquire();
    wl.release();
}