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Einführung

Eine Zusammenfassung einiger grundlegender Berührungs- / Bewegungshandhabungssysteme in der Android-API.

Parameter

Hörer Einzelheiten
onTouchListener Behandelt einzelne Tasten für Tasten, Flächen und mehr
onTouchEvent Ein Listener, der sich in Oberflächen befindet (zB SurfaceView). Muss nicht wie andere Listener eingestellt werden (z. B. onTouchListener)
onLongTouch Ähnlich wie bei onTouch, hört aber auf langes Drücken auf Tasten, Flächen und mehr.

Tasten

Berührungsereignisse, die sich auf einen Button beziehen, können wie folgt geprüft werden:

public class ExampleClass extends Activity implements View.OnClickListener, View.OnLongClickListener{
    public Button onLong, onClick;

    @Override
    public void onCreate(Bundle sis){
        super.onCreate(sis);
        setContentView(R.layout.layout);
        onLong = (Button) findViewById(R.id.onLong);
        onClick = (Button) findViewById(R.id.onClick);
        // The buttons are created. Now we need to tell the system that
        // these buttons have a listener to check for touch events.
        // "this" refers to this class, as it contains the appropriate event listeners.
        onLong.setOnLongClickListener(this);
        onClick.setOnClickListener(this);

        [OR]

        onClick.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v){
                // Take action. This listener is only designed for one button.
                // This means, no other input will come here.
                // This makes a switch statement unnecessary here.
            }
        });

        onLong.setOnLongClickListener(new View.OnLongClickListener(){
            @Override
            public boolean onLongClick(View v){
                // See comment in onClick.setOnClickListener().
            }
        });
    }

    @Override
    public void onClick(View v) {
        // If you have several buttons to handle, use a switch to handle them.
        switch(v.getId()){
            case R.id.onClick:
                // Take action.
                break;
        }
    }

    @Override
    public boolean onLongClick(View v) {
        // If you have several buttons to handle, use a switch to handle them.
        switch(v.getId()){
            case R.id.onLong:
                // Take action.
                break;
        }
        return false;
    }
}

Oberfläche

Berührungsereignishandler für Oberflächen (z. B. SurfaceView, GLSurfaceView und andere):

import android.app.Activity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.SurfaceView;
import android.view.View;

public class ExampleClass extends Activity implements View.OnTouchListener{
    @Override
    public void onCreate(Bundle sis){
        super.onCreate(sis);
        CustomSurfaceView csv = new CustomSurfaceView(this);
        csv.setOnTouchListener(this);
        setContentView(csv);
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        // Add a switch (see buttons example) if you handle multiple views
        // here you can see (using MotionEvent event) to see what touch event
        // is being taken. Is the pointer touching or lifted? Is it moving?
        return false;
    }
}

Oder alternativ (in der Oberfläche):

public class CustomSurfaceView extends SurfaceView {
    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        super.onTouchEvent(ev);
        // Handle touch events here. When doing this, you do not need to call a listener.
        // Please note that this listener only applies to the surface it is placed in 
        // (in this case, CustomSurfaceView), which means that anything else which is 
        // pressed outside the SurfaceView is handled by the parts of your app that
        // have a listener in that area.
        return true;
    }
}

Umgang mit Multitouch in einer Oberfläche

public class CustomSurfaceView extends SurfaceView {
    @Override
    public boolean onTouchEvent(MotionEvent e) {
        super.onTouchEvent(e);
        if(e.getPointerCount() > 2){
            return false; // If we want to limit the amount of pointers, we return false
                // which disallows the pointer. It will not be reacted on either, for
                // any future touch events until it has been lifted and repressed.
        }

        // What can you do here? Check if the amount of pointers are [x] and take action,
        // if a pointer leaves, a new enters, or the [x] pointers are moved.
        // Some examples as to handling etc. touch/motion events.

        switch (MotionEventCompat.getActionMasked(e)) {
            case MotionEvent.ACTION_DOWN:
            case MotionEvent.ACTION_POINTER_DOWN:
                // One or more pointers touch the screen.
                break;
            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_POINTER_UP:
                // One or more pointers stop touching the screen.
                break;
            case MotionEvent.ACTION_MOVE:
                // One or more pointers move.
                if(e.getPointerCount() == 2){
                    move();
                }else if(e.getPointerCount() == 1){
                    paint();
                }else{
                    zoom();
                }
                break;
        }
        return true; // Allow repeated action.    
    }
}


Modified text is an extract of the original Stack Overflow Documentation
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