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Few commands in bash.

find

find . -name "*.pyc" -print

find all files with .pyc postfix.

find . -name "*.pyc" -exec rm {} \;

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How to update UI in some non-main threads?

Solution 1:

Use Handler and send Message.

Solution 2:

Force to run on UI thread.

new Thread() {
    public void run() {
        runOnUiThread(new Runnable() {
 @Override

daa233

It can be implemented as following, but why?

String[] checkedToDeleteStringArray = checkedToDeleteHashSet.toArray(new String[0]);

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getWidth和getMeasuredWidth的区别

getWidth()

public final int getWidth() Return the width of the your view. Returns: int The width of your view, in pixels.

getWidth()得到的是view在父Layout中布局好后的宽度值，如果没有父布局，默认的父布局是整个屏幕。

getMeasuredWidth()

Like getMeasuredWidthAndState(), but only returns the raw width component (that is the result is masked by MEASURED_SIZE_MASK).

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自定义View时居中绘制文本需要注意

canvas.drawText(text, x, y, paint)

第一个参数是我们需要绘制的文本，第四个参数是我们的画笔。主要是第二和第三个参数的含义，这两个参数在不同的情况下的值还是不一样的， x默认是这个字符串的左边在屏幕的位置，如果设置了paint.setTextAlign(Paint.Align.CENTER);那就是字符的中心， y是指定这个字符baseline在屏幕上的位置。y不是这个字符中心在屏幕上的位置，而是baseline在屏幕上的位置。

【参考资料】http://blog.csdn.net/lovexieyuan520/article/details/43153275

daa233

C语言中数组的初始长度能不能由用户输入来决定？ 在我学C语言时，老师通过VC6.0告诉我们不可以。但是现在我用gcc(ver. 5.4)却可以编译成功，而且gcc没有对数组越界进行报错。具体来说，如果定义数组int a[n]，初始长度由用户输入的n来决定，那么越界部分既可以读取，也可以写入；如果定义数组int b[2]，即初始长度固定为某个整数，那么可以读取越界值b[2]、b[3]等，但是无法写入（运行程序时，向越界部分写入时会报stack smashing的错误）。读取到的越界部分的值均是没有初始化过的、内存中的随机值。

#include <stdio.h>

int main(int argc, char *argv[])
{
    int n;
    scanf("%d", &n);
    int a[n];

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/**
 * @file: PointerIncrement.cpp
 * @description: p为指针变量，p++代表什么？
 *
 * @author: Du Ang
 * @date: Apr. 21st, 2017
 */

#include <iostream>

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Libraries have been installed in: /usr/local/lib

If you ever happen to want to link against installed libraries in a given directory, LIBDIR, you must either use libtool, and specify the full pathname of the library, or use the '-LLIBDIR' flag during linking and do at least one of the following:

• add LIBDIR to the 'LD_LIBRARY_PATH' environment variable during execution
• add LIBDIR to the 'LD_RUN_PATH' environment variable

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# -*- encoding=utf-8 -*-
# Python2 代码

import os
import csv

# Open the csv and write headers.
with open("files_count.txt",'wb') as out:
    outwriter = csv.writer(out)
    # outwriter.writerow(['Directory','FilesInDir','FilesIncludingSubdirs'])

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def plot_confusion_matrix(cm, classes,
                          normalize=False,
                          title='Confusion matrix',
                          cmap=plt.cm.jet):
    """
    This function prints and plots the confusion matrix.
    Normalization can be applied by setting `normalize=True`.
    """
    plt.imshow(cm, interpolation='nearest', cmap=cmap)
    plt.title(title)