通过LinearLayout实现流式布局

这是我自己封装的一个工具类，可以拿来就可以使用了。值需要在构造方法中传入相应的类容就可以了

public class LinearAddUtil {
    int resourceId;
    ViewGroup container;
    Context context;
    List list = new ArrayList<>();
    int lineMargin = 50;
    int itemMargin = 50;

    public LinearAddUtil(int resourceId, ViewGroup container, List list, Context context, int lineMargin, int itemMargin) {
        this.resourceId = resourceId;
        this.container = container;
        this.list = list;
        this.context = context;
        this.lineMargin = lineMargin;
        this.itemMargin = itemMargin;
        init();
    }

    public void init() {
        //获取宽度
        int containerWidth = container.getMeasuredWidth() - container.getPaddingLeft() - container.getPaddingRight();
        TextView textView = (TextView) LayoutInflater.from(context).inflate(resourceId, null);
        //获取textView的padding
        int itemPadding = textView.getCompoundPaddingLeft() + textView.getPaddingRight();
        //通过画笔设置字体大小，便于后面测量item的宽度的准确性。但是他没有实际设置textview的大小，只是用于测量
        Paint paint = new Paint();
        paint.setTextSize(textView.getTextSize());

        //设置每行的间距
        LinearLayout.LayoutParams lineParam = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        lineParam.setMargins(0, lineMargin, 0, 0);

        //设置没列的间距
        LinearLayout.LayoutParams collwParam = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        collwParam.setMargins(0, 0, itemMargin, 0);


        //设置行，可以在layout添加条目
        LinearLayout layout = new LinearLayout(context);
        layout.setLayoutParams(new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
        layout.setOrientation(LinearLayout.HORIZONTAL);
        container.addView(layout);
        int remainWidth = containerWidth;
        for (int i = 0; i < list.size(); i++) {
            String text = list.get(i);
            float itemWidth = paint.measureText(text) + itemPadding;

            if (remainWidth > itemWidth) {
                addTextView(text, layout, collwParam);
            } else {
                layout = new LinearLayout(context);
                layout.setLayoutParams(new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
                layout.setOrientation(LinearLayout.HORIZONTAL);
                layout.setLayoutParams(lineParam);
                addTextView(text, layout, collwParam);
                container.addView(layout);
                remainWidth = containerWidth;
            }
            remainWidth = (int) (remainWidth - itemWidth + 0.5f) - itemMargin;
        }
        resetTextViewMarginsRight(layout);
    }

    //每一行添加的textView
    public void addTextView(String text, ViewGroup layout, ViewGroup.LayoutParams itemParams) {
        TextView tv = (TextView) LayoutInflater.from(context).inflate(resourceId, null);
        tv.setText(text);
        layout.addView(tv, itemParams);
    }

    //将每行最后一个textview的MarginsRight去掉
    private void resetTextViewMarginsRight(ViewGroup viewGroup) {
        TextView textView = (TextView) viewGroup.getChildAt(viewGroup.getChildCount() - 1);
        textView.setLayoutParams(new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
    }
    

}

 

这就是如何使用此工具的。

ublic class MainActivity extends AppCompatActivity {
    ViewGroup container;
    private boolean isFristTime = true;

    /** 标签之间的间距 px */
    final int itemMargins = 50;

    /** 标签的行间距 px */
    final int lineMargins = 50;
    List stringList=new ArrayList<>();
    private String[] tags = { "大约在冬季", "漂洋过海的来看你", "天下有情人", "我很认真", "夜夜夜夜", "想你的夜", "背叛", "趁早", "旧情绵绵", "谁明浪子心", "安妮",
            "说谎的爱人", "不浪漫的罪名", "不愿一个人", "风吹麦浪" };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        container= (ViewGroup) findViewById(R.id.container);
        Log.e("width", "onCreate: "+container.getMeasuredWidth());
        for (int i=0;i<10;i++){
            stringList.add("大在冬季"+i);
        }
    }

    @Override
    public void onWindowFocusChanged(boolean hasFocus) {
        super.onWindowFocusChanged(hasFocus);
        if (hasFocus && isFristTime){
            isFristTime = false;
//            init();
            LinearAddUtil linearUtil=new LinearAddUtil(R.layout.item_textview,container,stringList,this,50,50);

        }

    }




}

注意：

在Android中，有时我们需要测量控件的宽度和高度进行一些运算，特别是在自适应屏幕的时候，这些计算就变得特别必要，但是，如果我们直接在onCreate，

或者onStart、onResume(第一次执行时)方法，去获取控件的宽度和高度时，得出的结果会是0.

 

原因是：在执行这几个方法时，窗口Window对象并没有创建完成，而只是做了一些初始化的操作，想要获取控件的宽度和高度就要等到onDraw方法执行完成之后。