Question

I need to scrap <a> tags in html.

My goal is to scrap tags that has valid links inside their href attribute.

I think i'm very close to the answer, and this is the regex I wrote:

<a .*href=("|').*\.asp("|').*?>.*?<\/a>

http://regexr.com/3d989

第一个问题：

结果：

<a id='topnavbtn_tutorials' href='javascript:void(0);' onclick='w3_open_nav("tutorials")' title='Tutorials'>TUTORIALS <i class='fa fa-caret-down'></i><i class='fa fa-caret-up' style='display:none'></i></a><a id='topnavbtn_references' href='javascript:void(0);' onclick='w3_open_nav("references")' title='References'>REFERENCES <i class='fa fa-caret-down'></i><i class='fa fa-caret-up' style='display:none'></i></a><a id='topnavbtn_examples' href='javascript:void(0);' onclick='w3_open_nav("examples")' title='Examples'>EXAMPLES <i class='fa fa-caret-down'></i><i class='fa fa-caret-up' style='display:none'></i></a><a href='/forum/default.asp'>FORUM</a>

我只需要：

<a href='/forum/default.asp'>FORUM</a>

第二个问题：

结果：

<a href='/html/default.asp' class='w3-hide-small' title='HTML Tutorial'>HTML</a><a href='/css/default.asp' class='w3-hide-small' title='CSS Tutorial'>CSS</a><a href='/js/default.asp' class='w3-hide-small' title='JavaScript Tutorial'>JAVASCRIPT</a><a href='/sql/default.asp' class='w3-hide-small' title='SQL Tutorial'>SQL</a><a href='/php/default.asp' class='w3-hide-small' title='PHP Tutorial'>PHP</a><a href='/bootstrap/default.asp' class='w3-hide-small' title='Bootstrap Tutorial'>BOOTSTRAP</a><a href='/jquery/default.asp' class='w3-hide-small' title='jQuery Tutorial'>JQUERY</a><a href='/angular/default.asp' class='w3-hide-small' title='Angular Tutorial'>ANGULAR</a><a href='/xml/default.asp' class='w3-hide-small' title='XML Tutorial'>XML</a>

我需要它们作为单独的结果：

<a href='/html/default.asp' class='w3-hide-small' title='HTML Tutorial'>HTML</a>

<a href='/css/default.asp' class='w3-hide-small' title='CSS Tutorial'>CSS</a>

<a href='/js/default.asp' class='w3-hide-small' title='JavaScript Tutorial'>JAVASCRIPT</a>

依旧......

Answer 1

<强>更新。见下文。

如果你有字符串形式的HTML，你可以这样做：

// split the string up by anchor tags
// nested anchor tags is illegal, so this seems feasible:
var anchorArray = str.replace(/><a/g, '>¶<a').split('¶'); // ¶ is a placeholder to split

var matches = [];
var re = /<a .*href=["'].*\.asp["'].*?>.*?<\/a>/g;

// filter out the anchor elements with actual links in the final HTML
anchorArray.filter(function(element) { 
    if (re.test(element)) {
        matches.push(element); // keep the match in an array (2nd condition)
        return false; 
    }
    else return true;       
});

var returnedHTML = anchorArray.join('');  // HTML w/o actual links (1st condition)

请注意，解析HTML的首选方法不是使用正则表达式，而是使用HTML解析器。

Answer 2

这会对你有所帮助

var matches = [];

input_content.replace(/[^<]*(<a href="([^"]+)">/w*<\a>)/g, function () {
    matches.push(Array.prototype.slice.call(arguments, 1))
});

它将匹配变量的所有匹配作为数组返回！

Answer 3

public class MainActivity extends Activity {
TextView touchedXY, invertedXY, imgSize, colorRGB;
ImageView imgSource1;
Button b;
static final int CAMREQUEST = 1;
Uri fileUri;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    touchedXY = (TextView) findViewById(R.id.xy);
    invertedXY = (TextView) findViewById(R.id.invertedxy);
    imgSize = (TextView) findViewById(R.id.size);
    colorRGB = (TextView) findViewById(R.id.colorrgb);
    b = (Button) findViewById(R.id.Button01);

    b.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
            fileUri = null;
            fileUri = Uri.fromFile(new File(mediapath.getPath(), "Image" + System.currentTimeMillis() + ".jpg"));
            intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
            startActivityForResult(cameraIntent, CAMREQUEST);

        }
    });
}

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == CAMREQUEST) {
        Bitmap bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), fileUri);
        imgSource1 = (ImageView) findViewById(R.id.source1);
        imgSource1.setImageBitmap(image);
        imgSource1.setOnTouchListener(imgSourceOnTouchListener);
    }
}

OnTouchListener imgSourceOnTouchListener
        = new OnTouchListener() {

    @Override
    public boolean onTouch(View view, MotionEvent event) {

        float eventX = event.getX();
        float eventY = event.getY();
        float[] eventXY = new float[]{eventX, eventY};

        Matrix invertMatrix = new Matrix();
        ((ImageView) view).getImageMatrix().invert(invertMatrix);

        invertMatrix.mapPoints(eventXY);
        int x = Integer.valueOf((int) eventXY[0]);
        int y = Integer.valueOf((int) eventXY[1]);

        touchedXY.setText(
                "touched position: "
                        + String.valueOf(eventX) + " / "
                        + String.valueOf(eventY));
        invertedXY.setText(
                "touched position: "
                        + String.valueOf(x) + " / "
                        + String.valueOf(y));

        Drawable imgDrawable = ((ImageView) view).getDrawable();
        Bitmap bitmap = ((BitmapDrawable) imgDrawable).getBitmap();

        imgSize.setText(
                "drawable size: "
                        + String.valueOf(bitmap.getWidth()) + " / "
                        + String.valueOf(bitmap.getHeight()));

        //Limit x, y range within bitmap
        if (x < 0) {
            x = 0;
        } else if (x > (bitmap.getWidth() - 1)) {
            x = bitmap.getWidth() - 1;
        }

        if (y < 0) {
            y = 0;
        } else if (y > (bitmap.getHeight() - 1)) {
            y = bitmap.getHeight() - 1;
        }

        int touchedRGB = bitmap.getPixel(x, y);

        colorRGB.setText("touched color: " + "#" + Integer.toHexString(touchedRGB));
        colorRGB.setTextColor(touchedRGB);

        return true;
    }
};

输出：

$string = "<a href='/html/default.asp' class='w3-hide-small' title='HTML Tutorial'>HTML</a><a href='/css/default.asp' class='w3-hide-small' title='CSS Tutorial'>CSS</a><a href='/js/default.asp' class='w3-hide-small' title='JavaScript Tutorial'>JAVASCRIPT</a><a href='/sql/default.asp' class='w3-hide-small' title='SQL Tutorial'>SQL</a><a href='/php/default.asp' class='w3-hide-small' title='PHP Tutorial'>PHP</a><a href='/bootstrap/default.asp' class='w3-hide-small' title='Bootstrap Tutorial'>BOOTSTRAP</a><a href='/jquery/default.asp' class='w3-hide-small' title='jQuery Tutorial'>JQUERY</a><a href='/angular/default.asp' class='w3-hide-small' title='Angular Tutorial'>ANGULAR</a><a href='/xml/default.asp' class='w3-hide-small' title='XML Tutorial'>XML</a>";

preg_match_all('%<a href=\'/.*?\'>.*?</a>%s', $string, $matches, PREG_PATTERN_ORDER);
for ($i = 0; $i < count($matches[0]); $i++) {
    echo $matches[0][$i];
}

样本：

https://ideone.com/eFHU8n

注意：

Why you shouldn't use regex to parse html

废话锚（<a>) html tags

3 个答案: