Android LinearLayout实现自动换行效果

int withMode = MeasureSpec.getMode(widthMeasureSpec);int withSize = MeasureSpec.getSize(widthMeasureSpec);int heightMode = MeasureSpec.getMode(heightMeasureSpec);int heightSize = MeasureSpec.getSize(heightMeasureSpec);

public class WarpLinearLayout extends ViewGroup {   private Type mType;  private List<WarpLine> mWarpLineGroup;   public WarpLinearLayout(Context context) {    this(context, null);  }   public WarpLinearLayout(Context context, AttributeSet attrs) {    this(context, attrs, R.style.WarpLinearLayoutDefault);  }   public WarpLinearLayout(Context context, AttributeSet attrs, int defStyleAttr) {    super(context, attrs, defStyleAttr);    mType = new Type(context, attrs);  }   @Override  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {    int withMode = MeasureSpec.getMode(widthMeasureSpec);    int withSize = MeasureSpec.getSize(widthMeasureSpec);    int heightMode = MeasureSpec.getMode(heightMeasureSpec);    int heightSize = MeasureSpec.getSize(heightMeasureSpec);    int with = 0;    int height = 0;    int childCount = getChildCount();    /**     * 在调用childView。getMeasre之前必须先调用该行代码，用于对子View大小的测量     */    measureChildren(widthMeasureSpec, heightMeasureSpec);    /**     * 计算宽度     */    switch (withMode) {      case MeasureSpec.EXACTLY:        with = withSize;        break;      case MeasureSpec.AT_MOST:        for (int i = 0; i < childCount; i++) {          if (i != 0) {            with += mType.horizontal_Space;          }          with += getChildAt(i).getMeasuredWidth();        }        with += getPaddingLeft() + getPaddingRight();        with = with > withSize ? withSize : with;        break;      case MeasureSpec.UNSPECIFIED:        for (int i = 0; i < childCount; i++) {          if (i != 0) {            with += mType.horizontal_Space;          }          with += getChildAt(i).getMeasuredWidth();        }        with += getPaddingLeft() + getPaddingRight();        break;      default:        with = withSize;        break;     }    /**     * 根据计算出的宽度，计算出所需要的行数     */    WarpLine warpLine = new WarpLine();    /**     * 不能够在定义属性时初始化，因为onMeasure方法会多次调用     */    mWarpLineGroup = new ArrayList<WarpLine>();    for (int i = 0; i < childCount; i++) {      if (warpLine.lineWidth + getChildAt(i).getMeasuredWidth() + mType.horizontal_Space > with) {        if (warpLine.lineView.size() == 0) {          warpLine.addView(getChildAt(i));          mWarpLineGroup.add(warpLine);          warpLine = new WarpLine();        } else {          mWarpLineGroup.add(warpLine);          warpLine = new WarpLine();          warpLine.addView(getChildAt(i));        }      } else {        warpLine.addView(getChildAt(i));      }    }    /**     * 添加最后一行     */    if (warpLine.lineView.size() > 0 && !mWarpLineGroup.contains(warpLine)) {      mWarpLineGroup.add(warpLine);    }    /**     * 计算宽度     */    height = getPaddingTop() + getPaddingBottom();    for (int i = 0; i < mWarpLineGroup.size(); i++) {      if (i != 0) {        height += mType.vertical_Space;      }      height += mWarpLineGroup.get(i).height;    }    switch (heightMode) {      case MeasureSpec.EXACTLY:        height = heightSize;        break;      case MeasureSpec.AT_MOST:        height = height > heightSize ? heightSize : height;        break;      case MeasureSpec.UNSPECIFIED:        break;      default:        break;    }    setMeasuredDimension(with, height);  }   @Override  protected void onLayout(boolean changed, int l, int t, int r, int b) {    t = getPaddingTop();    for (int i = 0; i < mWarpLineGroup.size(); i++) {      int left = getPaddingLeft();      WarpLine warpLine = mWarpLineGroup.get(i);      int lastWidth = getMeasuredWidth() - warpLine.lineWidth;      for (int j = 0; j < warpLine.lineView.size(); j++) {        View view = warpLine.lineView.get(j);        if (isFull()) {//需要充满当前行时          view.layout(left, t, left + view.getMeasuredWidth() + lastWidth / warpLine.lineView.size(), t + view.getMeasuredHeight());          left += view.getMeasuredWidth() + mType.horizontal_Space + lastWidth / warpLine.lineView.size();        } else {          switch (getGrivate()) {            case 0://右对齐              view.layout(left + lastWidth, t, left + lastWidth + view.getMeasuredWidth(), t + view.getMeasuredHeight());              break;            case 2://居中对齐              view.layout(left + lastWidth / 2, t, left + lastWidth / 2 + view.getMeasuredWidth(), t + view.getMeasuredHeight());              break;            default://左对齐              view.layout(left, t, left + view.getMeasuredWidth(), t + view.getMeasuredHeight());              break;          }          left += view.getMeasuredWidth() + mType.horizontal_Space;        }      }      t += warpLine.height + mType.vertical_Space;    }  }   /**   * 用于存放一行子View   */  private final class WarpLine {    private List<View> lineView = new ArrayList<View>();    /**     * 当前行中所需要占用的宽度     */    private int lineWidth = getPaddingLeft() + getPaddingRight();    /**     * 该行View中所需要占用的最大高度     */    private int height = 0;     private void addView(View view) {      if (lineView.size() != 0) {        lineWidth += mType.horizontal_Space;      }      height = height > view.getMeasuredHeight() ? height : view.getMeasuredHeight();      lineWidth += view.getMeasuredWidth();      lineView.add(view);    }  }   /**   * 对样式的初始化   */  private final static class Type {    /*     *对齐方式 right 0，left 1，center 2    */    private int grivate;    /**     * 水平间距,单位px     */    private float horizontal_Space;    /**     * 垂直间距,单位px     */    private float vertical_Space;    /**     * 是否自动填满     */    private boolean isFull;     Type(Context context, AttributeSet attrs) {      if (attrs == null) {        return;      }      TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.WarpLinearLayout);      grivate = typedArray.getInt(R.styleable.WarpLinearLayout_grivate, grivate);      horizontal_Space = typedArray.getDimension(R.styleable.WarpLinearLayout_horizontal_Space, horizontal_Space);      vertical_Space = typedArray.getDimension(R.styleable.WarpLinearLayout_vertical_Space, vertical_Space);      isFull = typedArray.getBoolean(R.styleable.WarpLinearLayout_isFull, isFull);    }  }   public int getGrivate() {    return mType.grivate;  }   public float getHorizontal_Space() {    return mType.horizontal_Space;  }   public float getVertical_Space() {    return mType.vertical_Space;  }   public boolean isFull() {    return mType.isFull;  }   public void setGrivate(int grivate) {    mType.grivate = grivate;  }   public void setHorizontal_Space(float horizontal_Space) {    mType.horizontal_Space = horizontal_Space;  }   public void setVertical_Space(float vertical_Space) {    mType.vertical_Space = vertical_Space;  }   public void setIsFull(boolean isFull) {    mType.isFull = isFull;  }   /**   * 每行子View的对齐方式   */  public final static class Gravite {    public final static int RIGHT = 0;    public final static int LEFT = 1;    public final static int CENTER = 2;  }}

<?xml version="1.0" encoding="utf-8"?><resources>  <declare-styleable name="WarpLinearLayout">    <attr name="grivate" format="enum"><!--对齐方式 !-->      <enum name="right" value="0"></enum>      <enum name="left" value="1"></enum>      <enum name="center" value="2"></enum>    </attr>    <attr name="horizontal_Space" format="dimension"></attr>    <attr name="vertical_Space" format="dimension"></attr>    <attr name="isFull" format="boolean"></attr>  </declare-styleable></resources>

<style name="WarpLinearLayoutDefault">    <item name="grivate">left</item>    <item name="horizontal_Space">20dp</item>    <item name="vertical_Space">20dp</item>    <item name="isFull">false</item></style>

public class MainActivity extends Activity {  private Button btn;  private WarpLinearLayout warpLinearLayout;   @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    btn = (Button) findViewById(R.id.btn);    warpLinearLayout = (WarpLinearLayout) findViewById(R.id.warpLinearLayout);    btn.setOnClickListener(new View.OnClickListener() {      @Override      public void onClick(View v) {        int n = new Random().nextInt(10) + 5;        StringBuffer stringBuffer = new StringBuffer();        Random random = new Random();        Log.i("WarpLinearLayout","n="+n);        for (int i = 0; i < n; i++) {          stringBuffer.append((char)(65+random.nextInt(26)));          Log.i("WarpLinearLayout", "StringBuffer=" + stringBuffer.toString());        }        TextView tv = new TextView(MainActivity.this);        tv.setText(stringBuffer.toString()+"000");        tv.setBackgroundResource(R.drawable.radius_backgroup_yellow);        tv.setPadding(10,10,10,10);        warpLinearLayout.addView(tv);      }    });  }}

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:app="http://schemas.android.com/apk/res-auto"  xmlns:tools="http://schemas.android.com/tools"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:paddingBottom="@dimen/activity_vertical_margin"  android:paddingLeft="@dimen/activity_horizontal_margin"  android:paddingRight="@dimen/activity_horizontal_margin"  android:paddingTop="@dimen/activity_vertical_margin"  tools:context=".MainActivity">   <Button    android:id="@+id/btn"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:gravity="center"    android:text="add"    android:textSize="20dp" />   <com.example.customview.viewgroup.WarpLinearLayout    android:id="@+id/warpLinearLayout"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:layout_below="@id/btn"    android:background="#FF00FF00"    android:padding="10dp"    app:grivate="right"    app:horizontal_Space="10dp"    app:isFull="false"    app:vertical_Space="10dp"></com.example.customview.viewgroup.WarpLinearLayout></RelativeLayout>