java - Android 捕获 LinearLayout 上的触摸 : Cannot Resolve Symbol setOnTouchListener.

Question

我有一个(看似)简单的问题:我试图在子线性布局上设置 onTouchListener 但无法编译我的代码。当我尝试在所选 View 上使用 setOnTouchListener() 时，出现错误“无法解析符号 setOnTouchListener”。

如何记录 LinearLayout 上的触摸？我做错了什么？

MainActivity.java

   public class MainActivity extends FragmentActivity {
    public static LinearLayout glView;
    public static OpenGL_GLSurface foo;
    public TouchController touchSurface;

    void configView(){    // used to configure an opengl view 
        foo = new OpenGL_GLSurface(this);
        setContentView(R.layout.activity_main);
        glView = (LinearLayout)findViewById(R.id.openglsurface);
        RelativeLayout.LayoutParams glParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT);
        glView.addView(foo, glParams);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        ...
        touchSurface = new TouchController(this);  //initialize touchable surface
    }}

TouchController.java

public class TouchController {
private Context mContext;

public TouchController(Context c) {   //constructor
    mContext = c;  
}

View.OnTouchListener touch = new View.OnTouchListener() {       //set OnTouchListener to OpenGL View
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        switch (maskedAction) {
            //do stuff
        }
        return true;
    }
};
MainActivity.glView.setOnTouchListener(touch);   //Compilation Error here @ setOnTouchListener
}

Answer 1

问题出在您的 TouchController 中，当您设置触摸监听器时，此行:

MainActivity.glView.setOnTouchListener(touch);

该行代码是无效的 java 代码，因为它只是在类中徘徊。它必须位于构造函数等方法内部。像这样:

编辑:

public class TouchController {
    private Context mContext;

    public TouchController(Context c) {   //constructor
        mContext = c;

        View.OnTouchListener touch = new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                switch (maskedAction) {
                    //do stuff
                }
                return true;
            }
        };

        //Register touch listener here in constructor or in another method
        CourseListActivity.glView.setOnTouchListener(touch);
    }

}

您应该考虑在设置触摸监听器之前将成员变量“touch”的赋值移到构造函数内。它将更加有组织。