android - 无法使用 ontouchlistener 拖动自定义 ImageView

Question

我是 android 编程的新手...我正在尝试移动一个新创建的 ImageView ，该 ImageView 使用手势(特别是 ontouchlistener)添加到布局中。它设法添加了 ImageView ，但 ontouchlistener 只捕捉到ACTION_DOWN .. 这是我的代码:

package com.calengine;

import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.widget.FrameLayout;
import android.widget.FrameLayout.LayoutParams;
import android.widget.ImageView;
import android.widget.TextView;

public class coba extends CALEngineActivity implements OnClickListener, OnTouchListener{

    private ImageView movableimage;
    private FrameLayout layout;
    private LayoutParams params;
    int status;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.mainform2);

        layout = (AbsoluteLayout) findViewById(R.id.absLayoutAction);
        status = 0;
            movableimage = new ImageView(this);
            movableimage.setImageResource(R.drawable.icon_launcher);
            layout.addView(movableimage);
            movableimage.setOnTouchListener(this);
    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub

    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        TextView txt = (TextView) findViewById(R.id.textView1);
        LayoutParams layoutParams = (LayoutParams) movableimage.getLayoutParams();
        switch(event.getAction())
        {
        case MotionEvent.ACTION_DOWN:   
            txt.setText("Created");
            break;
        case MotionEvent.ACTION_MOVE:
            txt.setText("Moving");
            int x_cord = (int)event.getRawX();
            int y_cord = (int)event.getRawY();

            layoutParams.leftMargins = x_cord - 25;
            layoutParams.topMargins = y_cord - 75;

            movableimage.setLayoutParams(layoutParams);
            break;
        case MotionEvent.ACTION_UP:
            txt.setText("Up");
            break;
        default:
            break;
        }
        return false;
    }
}

我假设对于这些事件，textview 将显示相应的文本。但它只显示“已创建”，没有“移动”或“向上”...图像也不会移动...如何解决？

Answer 1

您需要在onTouch 方法中返回true。