OnDraw中没有得到所谓的从视图布局派生的自定义视图 [英] onDraw not getting called for a custom view derived from view in layout
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问题描述
我有一个自定义视图
.........
I have a custom view .........
package com.yasir.canvasTest;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Paint.Align;
import android.util.Log;
import android.view.View;
public class GraphView extends View {
private static final String TAG = "GraphView";
public static boolean BAR = true;
public static boolean LINE = false;
private Paint paint;
private float[] values;
private String[] horlabels;
private String[] verlabels;
private String title;
private boolean type;
public Canvas tmpCanvas = null;
public GraphView(Context context, float[] values, String title, String[] horlabels, String[] verlabels) {
super(context);
//setScrollContainer(true);
Log.v(TAG,"On GraphView==>");
paint = new Paint();
setWillNotDraw(false);
requestLayout();
invalidate();
}
@Override
protected void onDraw(Canvas canvas) {
Log.v(TAG,"<==On Draw");
/// drawing code here
invalidate();
}
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
Log.v(TAG,"On onMeasure==>");
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int parentWidth = MeasureSpec.getSize(widthMeasureSpec);
int parentHeight = MeasureSpec.getSize(heightMeasureSpec);
setMeasuredDimension(
parentWidth * 2, parentHeight);
}
}
...............
活动:的onCreate
...............
............... Activity: onCreate ...............
setContentView(R.layout.horscroll);
HorizontalScrollView hsView = (HorizontalScrollView) findViewById(R.id.hzsv);
LinearLayout ll = (LinearLayout) findViewById(R.id.linearParent);
ll.removeAllViews();
// create custom view and add to laywout
GraphView graphView = new GraphView(this, values, "GraphViewDemo",horlabels, verlabels, GraphView.LINE);
hsView.requestLayout();
hsView.setWillNotDraw(false);
ll.requestLayout();
ll.setWillNotDraw(false);
ll.addView(graphView);
.....................
XML
....................
..................... Xml ....................
<?xml version="1.0" encoding="utf-8"?>
<HorizontalScrollView
android:id="@+id/hzsv"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
xmlns:android="http://schemas.android.com/apk/res/android">
<LinearLayout android:id="@+id/linearParent"
android:layout_width="fill_parent"
android:layout_height="fill_parent"></LinearLayout>
</HorizontalScrollView>
..................
..................
问候,
亚西尔·佩尔韦
Regards, Yasir Perwez
推荐答案
试着用层次浏览器这是怎么回事检查。我怀疑你的观点是没有得到画,因为它有一个0宽度,这可能是出于两个原因(一个或两个):
Try checking with Hierarchy Viewer what's going on. I suspect your view is not getting drawn because it has a 0 width, and this could be for two reasons (either or both):
- 你没有设置任何
LinearLayout.LayoutParams
在自定义视图将它添加到布局之前,我不知道,如果默认的是的填写父之类; - 您
onMeasure()
是不完整的,应该考虑到还是模式(UNSPECIFIED
,完全
,AT_MOST
)至极,将取决于从布局PARAMS了。有没有保证的getSize()
返回父母的大小,作为框架意味着,你应该甚至不知道如果出现这种情况。
- you're not setting any
LinearLayout.LayoutParams
on your custom view before adding it to the layout, and I'm not sure if the default ones are of the "fill parent" kind; - your
onMeasure()
is incomplete, it should take into account also the mode (UNSPECIFIED
,EXACTLY
,AT_MOST
) wich will depend from the layout params too. There's no guarantee thatgetSize()
returns parent's size, and as the framework is meant, you shouldn't even know if that happens.
(@ slund的建议将可能是太有用)
(@slund's suggestion will probably be useful too)
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