Question

当我设置layout_weight =＆＃34; 1＆＃34;时，如何在自定义布局中获得高度？在纵向LinearLayout？

这是我的代码：

<LinearLayout
    android:id="@+id/timer_layout1"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:gravity="center_horizontal"
    android:orientation="vertical">
    <com.zzb.resume.views.DotView
        android:id="@+id/timer_line1"
        android:layout_width="2dp"
        android:layout_height="30dp" />
    <ImageView
        android:id="@+id/timer_icon"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/timer_line1"
        android:src="@mipmap/time2"/>
    <com.zzb.resume.views.DotView
        android:id="@+id/timer_line2"
        android:layout_width="2dp"
        android:layout_height="0dp"
        android:layout_weight="1" />
</LinearLayout>

在DotView中我得到height = 0。如何在layout_weight =＆＃34; 1＆＃34;？

时获得高度

DotView.java：

public class DotView extends View {
private Paint p;
private int height;
private int dash;

public DotView(Context context, AttributeSet attrs) {
    super(context, attrs);
    init(context);
}

public DotView(Context context) {
    super(context);
    init(context);
}

private void init(Context context) {
    p = new Paint(Paint.ANTI_ALIAS_FLAG);
    p.setStyle(Style.FILL);
    p.setColor(context.getResources().getColor(R.color.color_divide));


    Log.d("TAG", "--getMeasuredHeight>>" + height);
    Log.d("TAG", "--getHeight>>" + getHeight());
    final float scale = context.getResources().getDisplayMetrics().density;
    dash = (int) (6 * scale + 0.5f);

    ViewTreeObserver viewTreeObserver = getViewTreeObserver();
    if (viewTreeObserver.isAlive()) {
        viewTreeObserver.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                getViewTreeObserver().removeOnGlobalLayoutListener(this);
                height = getMeasuredHeight();
                Log.d("TAG", "--onGlobalLayout>>" + height);
            }
        });
    }
    viewTreeObserver.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
        @Override
        public boolean onPreDraw() {
            getViewTreeObserver().removeOnPreDrawListener(this);
            height = getMeasuredHeight();
            Log.d("TAG", "--onPreDraw>>" + height);
            return true;
        }
    });
}
@Override
protected void onDraw(Canvas canvas) {

    if(height>10){
        for(int i=0;i<height;i+=dash){
            canvas.drawLine(0, i, 0, i+=dash, p);
        }
    }
    super.onDraw(canvas);
}

@Override  
public void onSizeChanged(int w, int h, int oldw, int oldh) {  
    super.onSizeChanged(w, h, oldw, oldh); 
    height=h;
    p.setStrokeWidth(height);
    this.postInvalidate();
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    height = MeasureSpec.getSize(heightMeasureSpec);
    Log.d("TAG", "--onMeasure>>" + height);
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}

显示Logcat：所有结果均为0。

Answer 1

你不应该在onCreate()中获得高度，你可以在视图启动后设置一个监听器。以下是您可以看到的代码：

ViewTreeObserver vto = imageView.getViewTreeObserver(); 
        vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() { 
            public boolean onPreDraw() { 
                vto.removeOnPreDrawListener(this);
                int height = imageView.getMeasuredHeight(); 
                int width = imageView.getMeasuredWidth(); 
                return true; 
            } 
        });

我希望这对你有所帮助。

Answer 2

to achieve this you need to give weightsum in linear layout
<LinearLayout
        android:id="@+id/timer_layout1"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:gravity="center_horizontal"
        android:weightSum="2"
        android:orientation="vertical">
        <com.zzb.resume.views.DotView
            android:id="@+id/timer_line1"
            android:layout_width="2dp"
            android:layout_height="30dp" />
        <ImageView
            android:id="@+id/timer_icon"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@id/timer_line1"
            android:src="@mipmap/time2"/>
        <com.zzb.resume.views.DotView
            android:id="@+id/timer_line2"
            android:layout_width="2dp"
            android:layout_height="0dp"
            android:layout_weight="1" />
    </LinearLayout>

当layout_weight =＆＃34; 1＆＃34;时，在LinearLayout中获取高度

2 个答案: