在项目中有一个小功能需要实现，就是对多行文本进行排版布局，每一行的内容又分为两部分，左边为标题，右边为描述，左边内容长度不确定，右边的内容需要对齐，如有换行也需要对齐右边的文本。
一、效果图
可以看到内容分成了两部分，左边的颜色与右边不一致，右边的描述文案统一对齐。
二、实现方案
以上功能，由于输入内容输入行数不确定，并且左边的文案长度也不确定，因此不能直接在布局中实现，基于此这里主要实现了以下6种方式
方案1
采用自定义控件的方式，继承TextView，重新onDraw函数，实现如下：
/** * 计算出左边最长的显示字符串maxLeftWidth，之后draw每一行字符，右边的描述从maxLeftWidth开始draw * 当一行显示不完全时，折行并且空出maxLeftWidth的空格长度 */public class TypographyView1 extends TextView { private Paint leftPaint = new Paint(); private Paint rightPaint = new Paint(); private int fullWidth; private float textSize; private JSONArray array; private int middlePadding = 0; float maxLeftWidth = 0; int itemSize = 0; public TypographyView1(Context context) { super(context); init(); } public TypographyView1(Context context, AttributeSet attrs) { super(context, attrs); init(); } public TypographyView1(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(); } private void init() { textSize = getResources().getDimensionPixelSize(R.dimen.text_size_13); leftPaint.setAntiAlias(true); leftPaint.setTextSize(textSize); leftPaint.setColor(getResources().getColor(R.color.color_black_999999)); rightPaint.setAntiAlias(true); rightPaint.setTextSize(textSize); rightPaint.setColor(getResources().getColor(R.color.color_black)); middlePadding = getResources().getDimensionPixelSize(R.dimen.padding_value); } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); fullWidth = getWidth();// 整个textView的宽度 } public void setText(JSONArray array) { this.array = array; if (array != null) { try { int size = itemSize = array.length(); for (int i = 0; i < size; ++i) { JSONArray o = (JSONArray) array.get(i); String key = o.getString(0); String value = o.getString(1); if (TextUtils.isEmpty(key) || TextUtils.isEmpty(value)) { itemSize--; continue; } float curWidth = leftPaint.measureText(key); if (curWidth > maxLeftWidth) { maxLeftWidth = curWidth; } } maxLeftWidth = maxLeftWidth + middlePadding; invalidate(); } catch (Exception e) { } } } boolean setHeight = false; @Override protected void onDraw(Canvas canvas) { if (array == null) { return; } int lineCount = 0; try { JSONArray item; float offsetY; for (int i = 0; i < itemSize; ++i) { item = (JSONArray) array.get(i); offsetY = (lineCount + 1) * textSize; canvas.drawText(item.getString(0), 0, offsetY, leftPaint); String value = item.getString(1); float valueWidth = rightPaint.measureText(value); if (valueWidth > fullWidth - maxLeftWidth) {// 一行显示不完 char[] textCharArray = value.toCharArray(); float charWidth; float drawWidth = maxLeftWidth; for (int j = 0; j < textCharArray.length; j++) { charWidth = rightPaint.measureText(textCharArray, j, 1); if (fullWidth - drawWidth < charWidth) { lineCount++; drawWidth = maxLeftWidth; offsetY += textSize; } canvas.drawText(textCharArray, j, 1, drawWidth, offsetY, rightPaint); drawWidth += charWidth; } } else { canvas.drawText(value, maxLeftWidth, offsetY, rightPaint); } lineCount += 2; } if (!setHeight) { setHeight((lineCount + 1) * (int) textSize); setHeight = true; } } catch (JSONException e) { e.printStackTrace(); } }}添加了setText(JSONArray array)作为数据输入，并且在这里面测量了左边title的最大宽度，之后调用invalidate触发重绘，在onSizeChanged获取整个控件的宽度，重绘会调用onDraw函数，这里不需要调用super函数，TextView的onDraw函数做了非常多的操作，解析传入的数据，分别一行一行调用canvas来进行drawText操作，当绘制描述时，先计算宽度，如果超过剩余控件说明需要换行，最后调用setHeight设置高度，这个加一个判断条件，因为会触发requestLayout()进行重新布局和invalidate()进行重绘，如果不加判断会一直重绘。
方案2
方式2与方式1差不多，不同为所有计算都在onDraw函数中：
/** * 该方式与方式1很类似，只是所有的计算都放在了onDraw方法中。 */public class TypographyView2 extends TextView { private Paint paint1 = new Paint(); private Paint paint2 = new Paint(); private int middlePadding = 0; int width; private float textSize; private JSONArray array; public TypographyView2(Context context) { super(context); init(); } public TypographyView2(Context context, AttributeSet attrs) { super(context, attrs); init(); } public TypographyView2(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(); } private void init() { textSize = getResources().getDimensionPixelSize(R.dimen.text_size_13); paint1.setAntiAlias(true); paint1.setTextSize(textSize); paint1.setColor(getResources().getColor(R.color.color_black_999999)); paint2.setAntiAlias(true); paint2.setTextSize(textSize); paint2.setColor(getResources().getColor(R.color.color_black)); middlePadding = getResources().getDimensionPixelSize(R.dimen.padding_value); } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); width = getWidth();// 整个textView的宽度 } public void setText(JSONArray array) { this.array = array; if (array != null) { invalidate(); } } boolean setHeight = false; @Override protected void onDraw(Canvas canvas) { // super.onDraw(canvas); int lineCount = 0; int size = array.length(); float maxLeftWidth = 0; float drawWidth = 0; try { for (int i = 0; i < size; ++i) { JSONArray o = (JSONArray) array.get(i); String key = o.getString(0); float v = paint1.measureText(key); if (v > maxLeftWidth) { maxLeftWidth = v; } } maxLeftWidth = maxLeftWidth + middlePadding; for (int i = 0; i < size; ++i) { JSONArray o = (JSONArray) array.get(i); String key = o.getString(0); canvas.drawText(key, 0, (lineCount + 1) * textSize, paint1); String value = o.getString(1); char[] textCharArray = value.toCharArray(); float charWidth; drawWidth = maxLeftWidth; for (int j = 0; j < textCharArray.length; j++) { charWidth = paint1.measureText(textCharArray, j, 1); if (width - drawWidth < charWidth) { lineCount++; drawWidth = maxLeftWidth; } canvas.drawText(textCharArray, j, 1, drawWidth, (lineCount + 1) * textSize, paint2); drawWidth += charWidth; } lineCount += 2; } if (!setHeight) { setHeight((lineCount + 1) * (int) textSize + 5); setHeight = true; } } catch (JSONException e) { e.printStackTrace(); } }}该方案的实现是不太好的，方案1也是在此基础上进行调整的，在这里放出来只是为了说明，所有的计算不要全部放在onDraw里面，因为该方法可能会反复调用多次，这样就降低了性能。
方案3
将数据源拼接成SpannableString，重写onDraw函数，根据内容draw每一个字符：
/** * 该方法，是需要显示的内容先拼接成SpannableString，在onDraw方法中获取所有的char字符，一个一个比较 * 当为分号是，表示为key与value的分隔符。 */public class TypographyView3 extends TextView { private Paint leftPaint = new Paint(); private Paint rightPaint = new Paint(); int width; private String text; private float textSize; float maxLeftWidth = 0; private int middlePadding = 0; public TypographyView3(Context context) { super(context); init(); } public TypographyView3(Context context, AttributeSet attrs) { super(context, attrs); init(); } public TypographyView3(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(); } private void init() { textSize = getResources().getDimensionPixelSize(R.dimen.text_size_13); textSize = getResources().getDimensionPixelSize(R.dimen.text_size_13); leftPaint.setAntiAlias(true); leftPaint.setTextSize(textSize); leftPaint.setColor(getResources().getColor(R.color.color_black_999999)); rightPaint.setAntiAlias(true); rightPaint.setTextSize(textSize); rightPaint.setColor(getResources().getColor(R.color.color_black)); middlePadding = getResources().getDimensionPixelSize(R.dimen.padding_value); } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); width = getWidth();// 整个textView的宽度 } public void setText(JSONArray data) { if (data == null) { return; } try { int size = data.length(); for (int i = 0; i < size; ++i) { JSONArray o = (JSONArray) data.get(i); String key = o.getString(0); float v = leftPaint.measureText(key); if (v > maxLeftWidth) { maxLeftWidth = v; } } maxLeftWidth += middlePadding; SpannableStringBuilder ssb = new SpannableStringBuilder(); for (int i = 0; i < size; ++i) { addItem((JSONArray) data.get(i), ssb, i != 0); } setText(ssb, BufferType.SPANNABLE); } catch (Exception e) { } } private void addItem(JSONArray item, SpannableStringBuilder ssb, boolean breakLine) { try { if (item == null || item.length() == 0) { return; } String key = item.getString(0); String value = (item.length() >= 2) ? item.getString(1) : ""; if (TextUtils.isEmpty(key) && TextUtils.isEmpty(value)) { return; } if (breakLine) {// 换行 ssb.append("/r/n"); ssb.append("/r/n"); } SpannableString span = new SpannableString(key); // span.setSpan(new ForegroundColorSpan(getResources().getColor(R.color.colorAccent)), 0, key // .length(), // Spanned.SPAN_INCLUSIVE_EXCLUSIVE); ssb.append(span); ssb.append(value); } catch (JSONException e) { e.printStackTrace(); } } @Override protected void onDraw(Canvas canvas) { // super.onDraw(canvas); int lineCount = 0; text = this.getText().toString(); if (text == null) return; char[] textCharArray = text.toCharArray(); // 已绘的宽度 float drawWidth = 0; float charWidth; Paint paint = leftPaint; for (int i = 0; i < textCharArray.length; i++) { charWidth = leftPaint.measureText(textCharArray, i, 1); if (textCharArray[i] == '/n') { lineCount++; drawWidth = 0; paint = leftPaint; continue; } if (width - drawWidth < charWidth) { lineCount++; drawWidth = maxLeftWidth; } if (i > 1 && textCharArray[i - 1] == ':') { drawWidth = maxLeftWidth; paint = rightPaint; } canvas.drawText(textCharArray, i, 1, drawWidth, (lineCount + 1) * textSize, paint); drawWidth += charWidth; } //may be need set height //setHeight((lineCount + 1) * (int) textSize + 5); }}这里先计算左边title的最大宽度，同时将所有的数据拼接成一个SpannableStringBuilder，调用setText函数会触发重绘，在onDraw函数中进行处理，由于未重新super函数，因此SpannableString的setSpan函数失效，该方案主要根据分隔符来进行分割，因此分隔符需要唯一。
方案4
采用GridLayout方式实现，但是原始控件有展示问题，因此对此进行了修改：
public class Typography4Activity extends BaseActivity { public static void start(Context context) { Intent intent = new Intent(); intent.setClass(context, Typography4Activity.class); context.startActivity(intent); } private LinearLayout root; private Paint leftPaint = new Paint(); private float textSize; private float maxLeftWidth; private int middlePadding = 0; private float maxRightWidth; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); root = (LinearLayout) LayoutInflater.from(this).inflate(R.layout.activity_typography4, null); setContentView(root); initPaint(); findViews(); loadData(); } private void initPaint() { textSize = getResources().getDimensionPixelSize(R.dimen.text_size_13); leftPaint.setAntiAlias(true); leftPaint.setTextSize(textSize); leftPaint.setColor(getResources().getColor(R.color.color_black_999999)); middlePadding = getResources().getDimensionPixelSize(R.dimen.padding_value); } private void findViews() { } private void loadData() { addGridLayout(DataSource.getArray()); TextView view = new TextView(this); view.setText("修改后的实现"); view.setGravity(Gravity.CENTER); view.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 160)); root.addView(view); addModifyGridLayout(DataSource.getArray()); } private void addGridLayout(JSONArray data) { try { GridLayout layout = createGridLayout(); int size = data.length(); for (int i = 0; i < size; ++i) { JSONArray item = (JSONArray) data.get(i); String key = item.getString(0); String value = (item.length() >= 2) ? item.getString(1) : ""; GridLayout.Spec row = GridLayout.spec(i); GridLayout.Spec col1 = GridLayout.spec(0); GridLayout.Spec col2 = GridLayout.spec(1); GridLayout.LayoutParams params = new GridLayout.LayoutParams(row, col1); TextView title = getLeftTextView(key); layout.addView(title, params); params = new GridLayout.LayoutParams(row, col2); TextView desc = getRightTextView(value); layout.addView(desc, params); } root.addView(layout); } catch (Exception e) { } } @NonNull private TextView getRightTextView(String value) { TextView desc = new TextView(this); desc.setTextSize(13); desc.setTextColor(getResources().getColor(R.color.black)); desc.setText(value); return desc; } @NonNull private TextView getLeftTextView(String key) { TextView title = new TextView(this); title.setText(key); title.setPadding(0, middlePadding, middlePadding, 0); title.setTextColor(getResources().getColor(R.color.color_black_999999)); title.setTextSize(13); return title; } private void addModifyGridLayout(JSONArray data) { try { calculateLeftMaxWidth(data); GridLayout layout = createGridLayout(); int size = data.length(); for (int i = 0; i < size; ++i) { JSONArray item = (JSONArray) data.get(i); GridLayout.Spec row = GridLayout.spec(i); String key = item.getString(0); GridLayout.Spec col1 = GridLayout.spec(0); GridLayout.LayoutParams params = new GridLayout.LayoutParams(row, col1); TextView title = getLeftTextView(key); layout.addView(title, params); String value = (item.length() >= 2) ? item.getString(1) : ""; GridLayout.Spec col2 = GridLayout.spec(1); params = new GridLayout.LayoutParams(row, col2); TextView desc = getRightTextView(value); params.width = (int) maxRightWidth; params.height = ViewGroup.LayoutParams.WRAP_CONTENT; layout.addView(desc, params); } root.addView(layout); } catch (Exception e) { } } private void calculateLeftMaxWidth(JSONArray data) { try { DisplayUtil.init(this);// 这个可以在应用程序起来的时候init int size = data.length(); for (int i = 0; i < size; ++i) { JSONArray o = (JSONArray) data.get(i); String key = o.getString(0); String value = o.getString(1); if (TextUtils.isEmpty(key) || TextUtils.isEmpty(value)) { continue; } float curWidth = leftPaint.measureText(key); if (curWidth > maxLeftWidth) { maxLeftWidth = curWidth; } } maxLeftWidth = maxLeftWidth + middlePadding; maxRightWidth = DisplayUtil.screenWidth - DisplayUtil.dp2px(this, 32 + 10) - maxLeftWidth; } catch (Exception e) { } } private GridLayout createGridLayout() { GridLayout layout = new GridLayout(this); layout.setColumnCount(2); //layout.setRowCount(5); layout.setOrientation(GridLayout.HORIZONTAL); return layout; }} 如果直接创建一个GridLayout，里面添加每一项，如果描述过长都导致显示不全，这个是系统的一个bug，计算的宽度有问题，因此需要对此方案进行更改。
更改方式为先计算左边占用的最大宽度，在添加右边的项时，设置布局参数控制最大的长度。
方案5
采用每一行一个布局，手动一行一行进行添加：
public class Typography5Activity extends BaseActivity { public static void start(Context context) { Intent intent = new Intent(); intent.setClass(context, Typography5Activity.class); context.startActivity(intent); } private LinearLayout root; private Paint leftPaint = new Paint(); private float textSize; private float maxLeftWidth; private int middlePadding = 0; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); root = (LinearLayout) LayoutInflater.from(this).inflate(R.layout.activity_typography5, null); setContentView(root); initPaint(); loadData(); } private void initPaint() { textSize = getResources().getDimensionPixelSize(R.dimen.text_size_13); leftPaint.setAntiAlias(true); leftPaint.setTextSize(textSize); leftPaint.setColor(getResources().getColor(R.color.color_black_999999)); middlePadding = getResources().getDimensionPixelSize(R.dimen.padding_value); } private void loadData() { JSONArray array = DataSource.getArray(); calculateLeftMaxWidth(array); if (array != null) { try { int size = array.length(); for (int i = 0; i < size; ++i) { JSONArray o = (JSONArray) array.get(i); String key = o.getString(0); String value = o.getString(1); addItem(key, value); } } catch (Exception e) { } } } private void calculateLeftMaxWidth(JSONArray data) { try { int size = data.length(); for (int i = 0; i < size; ++i) { JSONArray o = (JSONArray) data.get(i); String key = o.getString(0); String value = o.getString(1); if (TextUtils.isEmpty(key) || TextUtils.isEmpty(value)) { continue; } float curWidth = leftPaint.measureText(key); if (curWidth > maxLeftWidth) { maxLeftWidth = curWidth; } } maxLeftWidth = maxLeftWidth + middlePadding; } catch (Exception e) { } } private void addItem(String key, String value) { LinearLayout layout = getItemLayout(); TextView left = (TextView) layout.findViewById(R.id.left); LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT); params.width = (int) maxLeftWidth; left.setLayoutParams(params); left.setText(key); TextView right = (TextView) layout.findViewById(R.id.right); right.setText(value); root.addView(layout); } private LinearLayout getItemLayout() { LinearLayout layout = (LinearLayout) LayoutInflater.from(this).inflate(R.layout.compose_item_layout, null); return layout; }}改方案也需要先计算左边的最大占用宽度，来设置右边占用的大小，每一项的布局如下：
<?xml version="1.0" encoding="utf-8"?><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:orientation="horizontal" android:paddingTop="@dimen/text_padding_10" tools:context=".activity.Typography1Activity"> <TextView android:id="@+id/left" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginRight="@dimen/text_padding_10" android:textColor="@color/color_black_999999" android:textSize="@dimen/text_size_13"/> <TextView android:id="@+id/right" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:textColor="@color/black" android:textSize="@dimen/text_size_13"/></LinearLayout>
每一行有两个TextView，左边宽度为自适应，右边占据剩下左右的位置，在计算出左边最大宽度后，重新设置左边每一个TextView占用的宽度。
方案6
方式与1差不多，但是不在继承TextView，而是直接继承View:
public class TypographyView4 extends View { private Paint leftPaint = new Paint(); private Paint rightPaint = new Paint(); private int fullWidth; private float textSize; private JSONArray array; private int middlePadding = 0; float maxLeftWidth = 0; int itemSize = 0; public TypographyView4(Context context) { super(context); init(); } public TypographyView4(Context context, AttributeSet attrs) { super(context, attrs); init(); } public TypographyView4(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(); } private void init() { textSize = getResources().getDimensionPixelSize(R.dimen.text_size_13); leftPaint.setAntiAlias(true); leftPaint.setTextSize(textSize); leftPaint.setColor(getResources().getColor(R.color.color_black_999999)); rightPaint.setAntiAlias(true); rightPaint.setTextSize(textSize); rightPaint.setColor(getResources().getColor(R.color.color_black)); middlePadding = getResources().getDimensionPixelSize(R.dimen.padding_value); } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); fullWidth = getWidth();// 整个textView的宽度 } public void setText(JSONArray array) { this.array = array; if (array != null) { try { int size = itemSize = array.length(); for (int i = 0; i < size; ++i) { JSONArray o = (JSONArray) array.get(i); String key = o.getString(0); String value = o.getString(1); if (TextUtils.isEmpty(key) || TextUtils.isEmpty(value)) { itemSize--; continue; } float curWidth = leftPaint.measureText(key); if (curWidth > maxLeftWidth) { maxLeftWidth = curWidth; } } maxLeftWidth = maxLeftWidth + middlePadding; invalidate(); } catch (Exception e) { } } } @Override protected void onDraw(Canvas canvas) { if (array == null) { return; } int lineCount = 0; try { JSONArray item; float offsetY; for (int i = 0; i < itemSize; ++i) { item = (JSONArray) array.get(i); offsetY = (lineCount + 1) * textSize; canvas.drawText(item.getString(0), 0, offsetY, leftPaint); String value = item.getString(1); float valueWidth = rightPaint.measureText(value); if (valueWidth > fullWidth - maxLeftWidth) {// 一行显示不完 char[] textCharArray = value.toCharArray(); float charWidth; float drawWidth = maxLeftWidth; for (int j = 0; j < textCharArray.length; j++) { charWidth = rightPaint.measureText(textCharArray, j, 1); if (fullWidth - drawWidth < charWidth) { lineCount++; drawWidth = maxLeftWidth; offsetY += textSize; } canvas.drawText(textCharArray, j, 1, drawWidth, offsetY, rightPaint); drawWidth += charWidth; } } else { canvas.drawText(value, maxLeftWidth, offsetY, rightPaint); } lineCount += 2; } } catch (JSONException e) { e.printStackTrace(); } }}该方案主要继承自View，不再继承TextView，由于在在上述方案中不在调用super，因此TextView已经退化为一个View,因此直接继承View。
总结
因为左边的宽度不确定，因此所有的方案都进行了同样的一个操作，就是测量了左边显示的最大宽度，后续的操作再根据该宽度进行调整。上述的方案中1，2，3，6都只需用一个View来进行显示，4，5都需要多个View进行显示。
完整的代码可以在查看链接上进行查看。
以上就是本文的全部内容，希望对大家的学习有所帮助。
新闻热点
疑难解答
