onKeyDown() 问题

发布于 2024-07-23 09:30:30 字数 595 浏览 17 评论 0原文

我想创建一个照片/视频捕获应用程序。

我创建了一个 CaptureView 类，它扩展了 SurfaceView 并将其放置在主窗体中。

主窗体的活动有 onCreateOptionsMenu() 方法来创建菜单。菜单工作正常，但后来我尝试实现一个方法 onKeyDown：

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {

    if(event.getAction() == KeyEvent.ACTION_DOWN) {
        switch(keyCode) {
        case KeyEvent.KEYCODE_CAMERA:
            videoPreview.TakePicture();
            return true;
        }
    }

    return super.onKeyDown(keyCode, event);
}

菜单不再出现，并且该方法没有捕获 onKeyDown 事件。

有谁知道这个问题的原因是什么？

原文

I would like to create a photo/video capture application.

I have created a CaptureView class which extends SurfaceView and placed it in the main form.

The main form's activity has onCreateOptionsMenu() method which creates a menu. The menu worked fine but then I tried to implement a method onKeyDown:

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {

    if(event.getAction() == KeyEvent.ACTION_DOWN) {
        switch(keyCode) {
        case KeyEvent.KEYCODE_CAMERA:
            videoPreview.TakePicture();
            return true;
        }
    }

    return super.onKeyDown(keyCode, event);
}

The menu doesn't appear anymore and the method doesn't catch onKeyDown event.

Does anyone know what could be the reason for this issue?

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荒路情人 2024-07-30 09:30:30

我遇到了类似的问题，并通过添加

this.requestFocus();
this.setFocusableInTouchMode(true);

SurfaceView 子类的构造函数来解决它。

I had a similar problem and solved it by adding

this.requestFocus();
this.setFocusableInTouchMode(true);

in the constructor of my SurfaceView subclass.

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内心旳酸楚 2024-07-30 09:30:30

我发现我为所有事件返回 true ，而我应该只为我正在使用的代码返回它。我将 return true 移至 if 语句的范围内，并返回 false 否则，这使我的菜单恢复了！

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    super.onKeyDown(keyCode, event);
    if (keyCode == KeyEvent.KEYCODE_BACK) {
        dba.close();
        Intent result = new Intent("Complete");
        setResult(Activity.RESULT_OK, result);
        finish();
        return true;
    }
    return false;
}

I found that I was returning true for all events, where I should only have been returning it for the code that I was using. I moved the return true inside the scope of the if statement and returned false otherwise That brought my menu back!

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    super.onKeyDown(keyCode, event);
    if (keyCode == KeyEvent.KEYCODE_BACK) {
        dba.close();
        Intent result = new Intent("Complete");
        setResult(Activity.RESULT_OK, result);
        finish();
        return true;
    }
    return false;
}

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丶视觉 2024-07-30 09:30:30

我解决了删除 if 语句的问题，如下所示：

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    switch(keyCode)
    {
        case KeyEvent.KEYCODE_CAMERA:
            videoPreview.TakePicture();
            return true;
    }
    return super.onKeyDown(keyCode, event);
}

i solved removing the if statement, like this:

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    switch(keyCode)
    {
        case KeyEvent.KEYCODE_CAMERA:
            videoPreview.TakePicture();
            return true;
    }
    return super.onKeyDown(keyCode, event);
}

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你对谁都笑 2024-07-30 09:30:30

我不知道为什么有时它不起作用，但对于我的一个应用程序来说，这个 keyDown() 工作正常，当我将它用于新应用程序时，它又不起作用。

但我有一个始终有效的解决方案：

@Override
public boolean dispatchKeyEvent (KeyEvent event) {
    if (event.getAction()==KeyEvent.ACTION_DOWN && event.getKeyCode()==KeyEvent.KEYCODE_BACK) {
        Toast.makeText(this, "Back button pressed", Toast.LENGTH_LONG).show();
        return true;
    }
    return false;
}

I don't know why sometimes it does not work, though for one of my apps this keyDown() is working fine and again when I use it for a new app then it does not work.

But I have a solution which always works:

@Override
public boolean dispatchKeyEvent (KeyEvent event) {
    if (event.getAction()==KeyEvent.ACTION_DOWN && event.getKeyCode()==KeyEvent.KEYCODE_BACK) {
        Toast.makeText(this, "Back button pressed", Toast.LENGTH_LONG).show();
        return true;
    }
    return false;
}

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