Question

我从xml创建了一个EditText，并在画布上绘制了很多东西。如何让EditText在画布上绘制的其他对象前面？

的xml：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity"
android:id="@+id/mainLayout"
android:clickable="true">

</RelativeLayout>

我在自定义SurfaceView类

上设置它

@Override
public void surfaceCreated(SurfaceHolder holder){

    thread = new MainThread(getHolder(), this); //Canvas is instatiated inside thread class
}

@Override
public void draw(Canvas canvas){
    //draw things
    EditText et = (EditText)findViewById(R.id.editText1);
}

主要活动：

@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    //Remove title
    requestWindowFeature(Window.FEATURE_NO_TITLE);

    //Set fullscreen
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
    setContentView(new GamePanel(this)); //GamePanel is the custom SurfaceView class

}

edit_text.xml：

<?xml version="1.0" encoding="utf-8"?>

<EditText xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" 
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/editText1"
    android:text="Hello World">
</EditText>

当前代码不显示EditText对象。我不知道它是否仍在画布下或根本没有显示。有什么想法和解释吗？提前谢谢。

Answer 1

只需在画布实例之后声明EditText，因此避免在SurfaceHolder.Callback的SurfaceCreated方法中初始化一个视图，因为这会导致在onDraw之前始终在背景中包含所有声明的内容它被称为;

只需尝试这个

        @Override
        public void surfaceCreated(SurfaceHolder holder){
           // nice part to start all the background independiently to onDraw for example
        Canvas canvas;
    canvas.drawRGB(255,255,255);

    // you will see that a white background will be drawed before all what you can put in onDraw class

    }

    @Override
    public void draw(Canvas canvas){
        //draw things
     EditText et = (EditText)findViewById(R.id.editText1);
// here is where you can initializate the editText

    }

Answer 2

我没有看到您将EditText添加到SurfaceView的位置。因此，如果您只想添加EditText而不添加任何父级（我的意思是RelativeLayout在您的xml中），那么您需要创建仅包含EditText的xml，例如调用edit_text.xml ：

<?xml version="1.0" encoding="utf-8"?>
<EditText
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/editText1"
    android:text="Hello World" />

然后你应该给它充气并添加到你的GamePanel：

@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    //Remove title
    requestWindowFeature(Window.FEATURE_NO_TITLE);

    //Set fullscreen
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

    GamePanel gamePanel = new GamePanel(this);
    EditText editText = (EditText) getLayoutInflater().inflate(R.layout.edit_text, null);
    gamePanel.addView(editText);

    setContentView(gamePanel); //GamePanel is the custom SurfaceView class

}

修改

我忘了将夸大的视图投射到EditText，因此它应该看起来像EditText editText = (EditText) getLayoutInflater().inflate(R.layout.edit_text, null);

编辑2：

要解决SurfaceView没有addView方法的错误，您可以改为创建FrameLayout或RelativeLayout，然后在其中添加SurfaceView和EditText：

GamePanel gamePanel = new GamePanel(this); RelativeLayout.LayoutParams gameParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT); gamePanel.setLayoutParams(gameParams); RelativeLayout content = new RelativeLayout(this); EditText editText = (EditText) getLayoutInflater().inflate(R.layout.edit_text, null); content.addView(gamePanel); content.addView(editText); setContentView(content);

如何使xml对象显示在画布中绘制的对象前面

2 个答案: