我对安卓中的布局测量非常困惑。基本上,我想在视图被布局之前获取其实际计算出的高度和宽度。我需要获取计算后的高度和宽度,因为我有一个隐藏的
LinearLayout
,我想在打开时使用viewpropertyanimator进行动画处理。在动画处理之前,我需要提供目标宽度(即计算出的宽度)给动画器。这个布局的宽度是动态的,因为它依赖于其android:weight
参数来确定宽度,所以我无法提供静态值。
这是我的活动类:
package com.example.testproject;
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.util.Log;
import android.view.Display;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.LinearLayout.LayoutParams;
public class TestActivity extends Activity
{
private LinearLayout gmailListContainer, yahooMailListContainer, windowsLiveListContainer;
private LinearLayout emailMessageContainer;
private Display display;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
this.setContentView(R.layout.activity_test);
gmailListContainer = (LinearLayout) this.findViewById(R.id.email_activity_gmail_layout);
yahooMailListContainer = (LinearLayout) this.findViewById(R.id.email_activity_yahoo_mail_layout);
windowsLiveListContainer = (LinearLayout) this.findViewById(R.id.email_activity_windows_live_layout);
emailMessageContainer = (LinearLayout) this.findViewById(R.id.email_activity_email_content_layout);
gmailListContainer.setBackgroundColor(Color.CYAN);
yahooMailListContainer.setBackgroundColor(Color.MAGENTA);
windowsLiveListContainer.setBackgroundColor(Color.GREEN);
emailMessageContainer.setBackgroundColor(Color.RED);
display = getWindowManager().getDefaultDisplay();
setMeasuredDimensions();
}
private void setMeasuredDimensions()
{
View v = this.findViewById(R.id.email_activity_layout);
v.measure(display.getWidth(), display.getHeight());
Log.v("EmailActivity", v.getMeasuredHeight() + ", " +v.getMeasuredWidth());
}
private void setWeight(LinearLayout container, float weight)
{
LinearLayout.LayoutParams params = (LayoutParams) container.getLayoutParams();
params.weight = weight;
container.setLayoutParams(params);
container.setVisibility(View.VISIBLE);
}
}
这是相关的布局资源:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/email_activity_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:baselineAligned="false">
<LinearLayout
android:id="@+id/email_activity_gmail_layout"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
/>
<LinearLayout
android:id="@+id/email_activity_yahoo_mail_layout"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
/>
<LinearLayout
android:id="@+id/email_activity_windows_live_layout"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
/>
<LinearLayout
android:id="@+id/email_activity_email_content_layout"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="0"
/>
v.measure(display.getWidth(), display.getHeight());
时,值会重新变为0。我修改了我的代码,首先记录高度和宽度,再次对视图执行测量命令,提供显示器的高度和宽度,并再次记录高度和宽度。在第一次记录中,返回了正确的值。在第二次记录中,这些值已被重置为0。为什么会这样? - Neilers