随机字符串TextView Android

Question

你好我有一个关于Random Lyrics.im的项目让你点击按钮并显示一个lyric.its soo basic.it将会得到String.i将在字符串array.textview添加歌词将在lyric字符串显示一个随机字符串。我的代码

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    TextView txt = (TextView) findViewById(R.id.textView2);
    Button btnget = (Button) findViewById(R.id.button1);
    Button btncpy = (Button) findViewById(R.id.button2);
}

字符串code.btnget会在这里得到一个随机的歌词。

<string name="words"/>
<string-array name="Lyrics">
    <item >Starving stomach would rumble from the honest politicians.</item>
    <item>But a life lived for others, is a life worth living.</item>
</string-array>

Answer 1

我不完全确定你的问题是什么，但我会假设你想知道如何制作你的应用程序。你需要一个歌词的文本视图和它下面的一个按钮。单击按钮时，应用程序将从歌曲列表中随机选择一首歌曲，并在文本视图中显示歌曲的歌词。

作为一个例子，我创建了一个执行这些操作的应用程序。下面是 activity-main.xml 文件。将YOUR-PACKAGE-NAME替换为您的包裹名称（例如 com.example.whatever ）。

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:id="@+id/layout"
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">

<YOUR-PACKAGE-NAME.AutoResizeTextView
    android:id="@+id/textview"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textSize="1000sp"
    android:gravity="center"


    android:maxLines="4"
    android:text="Row row, row your boat \n Gently down the stream \n Merrily, merrily, merrily, merrily \n Life is but a dream"/>

    <!--Above you should enter the song that will appear first  -->
    <!--In maxLines put the number of lines the starting song is-->


<Button
    android:id="@+id/button"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_below="@+id/textview"
    android:text="Click for Random Song"
    android:textSize="25sp"/>

创建一个名为AutoResizeTextView的新类，并将此代码粘贴到包行下方。我从https://stackoverflow.com/a/17782522/5260943

的stackoverflow回答中得到了这个

import android.annotation.TargetApi;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.RectF;
import android.os.Build;
import android.text.Layout.Alignment;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.util.SparseIntArray;
import android.util.TypedValue;
import android.widget.TextView;

public class AutoResizeTextView extends TextView {
private interface SizeTester {
    /**
     *
     * @param suggestedSize
     *            Size of text to be tested
     * @param availableSpace
     *            available space in which text must fit
     * @return an integer < 0 if after applying {@code suggestedSize} to
     *         text, it takes less space than {@code availableSpace}, > 0
     *         otherwise
     */
    public int onTestSize(int suggestedSize, RectF availableSpace);
}

private RectF mTextRect = new RectF();

private RectF mAvailableSpaceRect;

private SparseIntArray mTextCachedSizes;

private TextPaint mPaint;

private float mMaxTextSize;

private float mSpacingMult = 1.0f;

private float mSpacingAdd = 0.0f;

private float mMinTextSize = 20;

private int mWidthLimit;

private static final int NO_LINE_LIMIT = -1;
private int mMaxLines;

private boolean mEnableSizeCache = true;
private boolean mInitiallized;

public AutoResizeTextView(Context context) {
    super(context);
    initialize();
}

public AutoResizeTextView(Context context, AttributeSet attrs) {
    super(context, attrs);
    initialize();
}

public AutoResizeTextView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    initialize();
}

public void initialize() {
    mPaint = new TextPaint(getPaint());
    mMaxTextSize = getTextSize();
    mAvailableSpaceRect = new RectF();
    mTextCachedSizes = new SparseIntArray();
    if (mMaxLines == 0) {
        // no value was assigned during construction
        mMaxLines = NO_LINE_LIMIT;
    }
    mInitiallized = true;
}

@Override
public void setText(final CharSequence text, BufferType type) {
    super.setText(text, type);
    adjustTextSize(text.toString());
}

@Override
public void setTextSize(float size) {
    mMaxTextSize = size;
    mTextCachedSizes.clear();
    adjustTextSize(getText().toString());
}

@Override
public void setMaxLines(int maxlines) {
    super.setMaxLines(maxlines);
    mMaxLines = maxlines;
    reAdjust();
}

public int getMaxLines() {
    return mMaxLines;
}

@Override
public void setSingleLine() {
    super.setSingleLine();
    mMaxLines = 1;
    reAdjust();
}

@Override
public void setSingleLine(boolean singleLine) {
    super.setSingleLine(singleLine);
    if (singleLine) {
        mMaxLines = 1;
    } else {
        mMaxLines = NO_LINE_LIMIT;
    }
    reAdjust();
}

@Override
public void setLines(int lines) {
    super.setLines(lines);
    mMaxLines = lines;
    reAdjust();
}

@Override
public void setTextSize(int unit, float size) {
    Context c = getContext();
    Resources r;

    if (c == null)
        r = Resources.getSystem();
    else
        r = c.getResources();
    mMaxTextSize = TypedValue.applyDimension(unit, size,
            r.getDisplayMetrics());
    mTextCachedSizes.clear();
    adjustTextSize(getText().toString());
}

@Override
public void setLineSpacing(float add, float mult) {
    super.setLineSpacing(add, mult);
    mSpacingMult = mult;
    mSpacingAdd = add;
}

/**
 * Set the lower text size limit and invalidate the view
 *
 * @param minTextSize
 */
public void setMinTextSize(float minTextSize) {
    mMinTextSize = minTextSize;
    reAdjust();
}

private void reAdjust() {
    adjustTextSize(getText().toString());
}

private void adjustTextSize(String string) {
    if (!mInitiallized) {
        return;
    }
    int startSize = (int) mMinTextSize;
    int heightLimit = getMeasuredHeight() - getCompoundPaddingBottom()
            - getCompoundPaddingTop();
    mWidthLimit = getMeasuredWidth() - getCompoundPaddingLeft()
            - getCompoundPaddingRight();
    mAvailableSpaceRect.right = mWidthLimit;
    mAvailableSpaceRect.bottom = heightLimit;
    super.setTextSize(
            TypedValue.COMPLEX_UNIT_PX,
            efficientTextSizeSearch(startSize, (int) mMaxTextSize,
                    mSizeTester, mAvailableSpaceRect));
}

private final SizeTester mSizeTester = new SizeTester() {
    @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
    @Override
    public int onTestSize(int suggestedSize, RectF availableSPace) {
        mPaint.setTextSize(suggestedSize);
        String text = getText().toString();
        boolean singleline = getMaxLines() == 1;
        if (singleline) {
            mTextRect.bottom = mPaint.getFontSpacing();
            mTextRect.right = mPaint.measureText(text);
        } else {
            StaticLayout layout = new StaticLayout(text, mPaint,
                    mWidthLimit, Alignment.ALIGN_NORMAL, mSpacingMult,
                    mSpacingAdd, true);
            // return early if we have more lines
            if (getMaxLines() != NO_LINE_LIMIT
                    && layout.getLineCount() > getMaxLines()) {
                return 1;
            }
            mTextRect.bottom = layout.getHeight();
            int maxWidth = -1;
            for (int i = 0; i < layout.getLineCount(); i++) {
                if (maxWidth < layout.getLineWidth(i)) {
                    maxWidth = (int) layout.getLineWidth(i);
                }
            }
            mTextRect.right = maxWidth;
        }

        mTextRect.offsetTo(0, 0);
        if (availableSPace.contains(mTextRect)) {
            // may be too small, don't worry we will find the best match
            return -1;
        } else {
            // too big
            return 1;
        }
    }
};

/**
 * Enables or disables size caching, enabling it will improve performance
 * where you are animating a value inside TextView. This stores the font
 * size against getText().length() Be careful though while enabling it as 0
 * takes more space than 1 on some fonts and so on.
 *
 * @param enable
 *            enable font size caching
 */
public void enableSizeCache(boolean enable) {
    mEnableSizeCache = enable;
    mTextCachedSizes.clear();
    adjustTextSize(getText().toString());
}

private int efficientTextSizeSearch(int start, int end,
                                    SizeTester sizeTester, RectF availableSpace) {
    if (!mEnableSizeCache) {
        return binarySearch(start, end, sizeTester, availableSpace);
    }
    String text = getText().toString();
    int key = text == null ? 0 : text.length();
    int size = mTextCachedSizes.get(key);
    if (size != 0) {
        return size;
    }
    size = binarySearch(start, end, sizeTester, availableSpace);
    mTextCachedSizes.put(key, size);
    return size;
}

private static int binarySearch(int start, int end, SizeTester sizeTester,
                                RectF availableSpace) {
    int lastBest = start;
    int lo = start;
    int hi = end - 1;
    int mid = 0;
    while (lo <= hi) {
        mid = (lo + hi) >>> 1;
        int midValCmp = sizeTester.onTestSize(mid, availableSpace);
        if (midValCmp < 0) {
            lastBest = lo;
            lo = mid + 1;
        } else if (midValCmp > 0) {
            hi = mid - 1;
            lastBest = hi;
        } else {
            return mid;
        }
    }
    // make sure to return last best
    // this is what should always be returned
    return lastBest;

}

@Override
protected void onTextChanged(final CharSequence text, final int start,
                             final int before, final int after) {
    super.onTextChanged(text, start, before, after);
    reAdjust();
}

@Override
protected void onSizeChanged(int width, int height, int oldwidth,
                             int oldheight) {
    mTextCachedSizes.clear();
    super.onSizeChanged(width, height, oldwidth, oldheight);
    if (width != oldwidth || height != oldheight) {
        reAdjust();
    }
}
}

然后，将此代码粘贴到MainActivity类的包行下面。

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.Random;

public class MainActivity extends Activity {

TextView textView;
Button button;
int songsSize;

ArrayList<String[]>  songs = new ArrayList<>();

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

    songs.add(new String[]{"Row row row your boat", "Gently down the stream", "Merrily merrily merrily", "Life is but a dream"});
    songs.add(new String[]{"Ring-a-round the rosie", "Pockets full of posies", "Ashes! Ashes!", "We all fall down"});
    songs.add(new String[]{"Twinkle twinkle little star", "How I wonder what you are", "Up above the world you fly", "Like a diamond in the sky"});
    songs.add(new String[]{"Humpty Dumpty sat on a wall", "Humpty Dumpty had a great fall", "All the king's horses and all the king's men", "Couldn't put Humpty together again"});
    songs.add(new String[]{"Baa baa black sheep", "Have you any wool?", "Yes, sir, yes, sir", "Three bags full"});
    songs.add(new String[]{"London Bridge is falling down", "Falling down, falling down", "London Bridge is falling down", "My fair lady"});

    //Replace the above songs with whatever songs you want,
    //splitting the lines of the songs with commas

    songsSize = songs.size();
    textView = (AutoResizeTextView)findViewById(R.id.textview);
    button = (Button)findViewById(R.id.button);

    //button.setTextSize(textView.getTextSize());
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            changeSong();
        }
    });
}

String getSongFromArray(String[] song){
    String textViewText = "";

    for(int i=0; i<song.length-1; i++){
        textViewText = textViewText + song[i] + System.getProperty ("line.separator");
    }

    return textViewText + song[song.length-1];
}

void changeSong(){
    String[] song = songs.get(new Random().nextInt(songsSize));
    String songText = getSongFromArray(song);

    if(textView.getText().toString().equals(songText)) {
        changeSong();
    } else{
        textView.setText(songText);
        textView.setLines(song.length);
        textView.setMaxLines(song.length);
        textView.setTextSize(1000);
        //button.setTextSize(textView.getTextSize());
    }
}
}

用您自己的歌曲替换MainActivity类中的歌曲，用逗号分隔歌词的行。在XML文件中，将“行，行，划船”文本替换为首先出现的歌曲，并将maxLines更改为该歌曲中的行数。