Android 自动换行的ViewGroup -

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Android 自动换行的ViewGroup

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自动换行

之前项目遇到需要自动换行的linearlayout，当时没有实现出来，现在已经搞定，把它分享出来。

我用的是viewgroup写的，其实也可以用其他容器控件写，有需要的同学自己去扩展。

package com.example.test.auto.change.lines;

import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
/**
 * 自动换行ViewGroup
 */
public class AutoChangeLinesViewGroup extends ViewGroup {

	private final String TAG = "AutoChangeLinesViewGroup";
	private final static int VIEW_MARGIN = 2;
	
	public AutoChangeLinesViewGroup(Context context) {
		super(context);
		// TODO Auto-generated constructor stub
	}

	public AutoChangeLinesViewGroup(Context context, AttributeSet attrs) {
		super(context, attrs);
		// TODO Auto-generated constructor stub
	}

	public AutoChangeLinesViewGroup(Context context, AttributeSet attrs,int defStyle) {
		super(context, attrs, defStyle);
		// TODO Auto-generated constructor stub
	}

	@Override
	protected void onLayout(boolean changed, int l, int t, int r, int b) {
		// TODO Auto-generated method stub
		Log.d(TAG, "changed ==== " + changed + " l == " + l + " t === " + t + " r == " + r + " b== " + b);
		
		int row = 0;
		int width = 0;
		int height = 0;
		if(changed){
			final int count = getChildCount();
	        for(int i = 0; i < count; i++){
	        	final View child = this.getChildAt(i);
	            int measuredWidth = child.getMeasuredWidth();
	            int measuredHeight = child.getMeasuredHeight();
	            width += measuredWidth + VIEW_MARGIN;
	            height = row * ( measuredHeight + VIEW_MARGIN ) + VIEW_MARGIN + measuredHeight;
	            if(width > r){
	                width = measuredWidth + VIEW_MARGIN;
	                if(width > r){
	                	width = r - l ;
	                }
	                row ++;
	            	height = row * ( measuredHeight + VIEW_MARGIN ) + VIEW_MARGIN + measuredHeight;
	            	// 超出最大范围之后不绘制
	            	child.layout(0, height - measuredHeight, width, height);
	            }else {
	            	child.layout(width - measuredWidth, height - measuredHeight, width, height);
	            }
			}
		}
		
		
	}

	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
		// TODO Auto-generated method stub
		
		for(int i = 0 ; i < getChildCount() ; i ++){
			final View childView = getChildAt(i);
			childView.measure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);
		}
		super.onMeasure(widthMeasureSpec, heightMeasureSpec);
		
	}
	
	
}

此控件有一个问题，如果它外层有Viewgroup，那么此控件不能计算本身高度，导致没法看到期望的效果，下面我再次贴出完美解决此问题的代码

package com.app.widget;

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;

import com.app.R;

public class AutoChangeLinesViewGroup extends ViewGroup {
	// 横向间距
	private static int VIEW_WIDTH_MARGIN = 10;  
	// 纵向间距
	private static int VIEW_HEIGHT_MARGIN = 10;  

	public AutoChangeLinesViewGroup(Context context) {
		super(context);
		// TODO Auto-generated constructor stub
		init(context);
	}

	public AutoChangeLinesViewGroup(Context context, AttributeSet attrs) {
		super(context, attrs);
		// TODO Auto-generated constructor stub
		init(context);
	}

	public AutoChangeLinesViewGroup(Context context, AttributeSet attrs,
			int defStyle) {
		super(context, attrs, defStyle);
		// TODO Auto-generated constructor stub
		init(context);
	}

	private void init(Context context){
		VIEW_WIDTH_MARGIN = (int) context.getResources().getDimension(R.dimen.nearby_releasse_thtem_tag_height);
		VIEW_HEIGHT_MARGIN = (int) context.getResources().getDimension(R.dimen.nearby_releasse_thtem_tag_width);
	}
	
	@Override
	protected void onLayout(boolean changed, int l, int t, int r, int b) {
		// TODO Auto-generated method stub
        int width = 0;  
        int height = 0;
        int row = 0 ;
        if(changed){  
            final int count = getChildCount();  
            for(int i = 0; i < count; i++){  
                final View child = this.getChildAt(i);  
                int measuredWidth = child.getMeasuredWidth();  
                int measuredHeight = child.getMeasuredHeight();  
                width += measuredWidth + VIEW_WIDTH_MARGIN;  
                height = row * ( measuredHeight + VIEW_HEIGHT_MARGIN ) + VIEW_HEIGHT_MARGIN + measuredHeight;  
                if(width > getWidth()){  
                    width = measuredWidth + VIEW_WIDTH_MARGIN;  
                    if(width > getWidth()){  
                        width = getWidth() ;  
                    }  
                    row ++;  
                    height = row * ( measuredHeight + VIEW_HEIGHT_MARGIN ) + VIEW_HEIGHT_MARGIN + measuredHeight;  
                    // 超出最大范围之后不绘制  
                   child.layout(0, height - measuredHeight, width - VIEW_WIDTH_MARGIN, height);  
                }else {  
                   child.layout(width - measuredWidth - VIEW_WIDTH_MARGIN, height - measuredHeight, width - VIEW_WIDTH_MARGIN, height);  
                } 
            }
        }  
	}
	
	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
		// TODO Auto-generated method stub
		super.onMeasure(widthMeasureSpec, heightMeasureSpec);
		// 获取系统自动测量的该ViewGroup的大小
		int widthSize = MeasureSpec.getSize(widthMeasureSpec);
		int heightSize = MeasureSpec.getSize(heightMeasureSpec);
		if(heightSize > 0 && widthSize > 0){
			setMeasuredDimension(widthSize, heightSize);
			return ;
		}
		
		// 我们也可调用setMeasuredDimension()重新设置测量结果
		// 修改了系统自动测量的子View的大小
		int childCount = this.getChildCount();

		int width = 0;  
        int height = 0;
        int row = 0 ;
        
		for (int i = 0; i < childCount; i++) {
			View childView = getChildAt(i);
			 int w = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
			 int h = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
			 childView.measure(w, h);
			// 获取每个子View测量所得的宽和高
			int childMeasuredWidth = childView.getMeasuredWidth();
			int childMeasuredHeight = childView.getMeasuredHeight();
            width += childMeasuredWidth + VIEW_WIDTH_MARGIN;  
            height = row * ( childMeasuredHeight + VIEW_HEIGHT_MARGIN ) + VIEW_HEIGHT_MARGIN + childMeasuredHeight;  
            if(width > widthSize){  
                width = childMeasuredWidth + VIEW_WIDTH_MARGIN;  
                if(width > widthSize){  
                    width = widthSize ;  
                }  
                row ++;  
                height = row * ( childMeasuredHeight + VIEW_HEIGHT_MARGIN ) + VIEW_HEIGHT_MARGIN + childMeasuredHeight;  
            }
		}
		
		setMeasuredDimension(widthSize, height);
	}
}

需要的朋友自己下载