我想知道我的textview是否在可见的屏幕区域内.

但似乎没有什么对我有用.

我以前检查过的代码是

Rect rect = new Rect();

//textview intialized in onCreate as text1

text1.getHitRect(rect);

text1.measure(0, 0);

//layout is the parent layout (linear) in which i am adding the text view

Rect acctualView = new Rect(Math.round(layout.getX()), Math.round(layout.getY()),

Math.round(layout.getX() + layout.getWidth()), Math.round(layout.getY() +layout.getHeight()));

if(Rect.intersects(acctualView, rect))

{

Toast.makeText(context, "visible", Toast.LENGTH_LONG).show();

}else {

Toast.makeText(context, "Not visible ", Toast.LENGTH_LONG).show();

}

textview和layout的每个宽度和高度都给我0“零”,

请让我知道如何解决这个问题,并知道视图是否在可见区域内

这是我的完整活动代码

public class MainActivity extends Activity {

private TextView text1, text2, text3, text4, text5, text6;

private Context context;

private LinearLayout layout;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

context = getLayoutInflater().getContext();

layout = (LinearLayout) findViewById(R.id.parentLayout);

setTextViews();

checkViewAndUpdate();

}

private void checkViewAndUpdate() {

Rect rect = new Rect();

layout.getHitRect(rect);

if (text1.getLocalVisibleRect(rect)) {

Toast.makeText(context, "visible", Toast.LENGTH_LONG).show();

} else {

Toast.makeText(context, "Not visible", Toast.LENGTH_LONG).show();

}

}

private void setTextViews() {

text1 = new TextView(context);

text2 = new TextView(context);

text3 = new TextView(context);

text4 = new TextView(context);

text5 = new TextView(context);

text6 = new TextView(context);

text1.setText("text1");

text2.setText("text2");

text3.setText("text3");

text4.setText("text4");

text5.setText("text5");

text6.setText("text6");

text1.setTextSize(30);

text2.setTextSize(30);

text3.setTextSize(30);

text4.setTextSize(30);

text5.setTextSize(30);

text6.setTextSize(30);

//layout.removeAllViews();

layout.addView(text1);

layout.addView(text2);

layout.addView(text3);

layout.addView(text4);

layout.addView(text5);

layout.addView(text6);

}

}

我的布局只包含LinearLayout(空)

解决方法:

正如我在评论中写的那样,检查onCreate上的可见rect是行不通的.

在onCreate结束时尝试此代码(而不是直接调用checkAndUpdate()).

layout.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {

@Override

public void onGlobalLayout() {

checkViewAndUpdate();

}

});

如果您在onCreate中添加了视图,则视图布局无法完成​​.是的,这次用户无法看到实际活动,并且未设置视图的实际大小.

onGlobalLayout将在视图布局结束时调用(并且活动可见).

在那个时刻,我们现在可以获得它们的大小和位置！

仅供参考,您可以通过在onGlobalLayout()中调用layout.getViewTreeObserver().removeOnGlobalLayoutListener(this)来删除此侦听器.

标签：android,textview

来源： https://codeday.me/bug/20190624/1276903.html