以编程方式制作单个按钮宽度以填充父级

Question

如何使单个按钮宽度以编程方式填充父级？我已经这样做了，但它似乎无法工作它仍然位于左上角，宽度只是包装内容......这里是按钮创建的一些代码......

public class TEST_GIFDisplay extends Activity implements View.OnClickListener {

    SurfaceView sview;
    GifRun gr = new GifRun();
    Button btnBack;

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        sview = new SurfaceView(this);
        sview.setZOrderOnTop(true);

        gr.LoadGiff(sview, this, R.drawable.smiley);

        LinearLayout linearLayout1 = new LinearLayout(this);
        linearLayout1.setOrientation(LinearLayout.VERTICAL);
        linearLayout1.setBackgroundColor(Color.parseColor("#27ae60"));
        linearLayout1.setLayoutParams(new ViewGroup.LayoutParams(
                ViewGroup.LayoutParams.WRAP_CONTENT,
                ViewGroup.LayoutParams.WRAP_CONTENT));

        LinearLayout linearLayout2 = new LinearLayout(this);
        linearLayout2.setOrientation(LinearLayout.VERTICAL);
        linearLayout2.setBackgroundColor(Color.parseColor("#27ae60"));
        linearLayout2.setLayoutParams(new ViewGroup.LayoutParams(
                ViewGroup.LayoutParams.WRAP_CONTENT,
                ViewGroup.LayoutParams.WRAP_CONTENT));

        LinearLayout.LayoutParams p = new   
        LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT,   
        LinearLayout.LayoutParams.WRAP_CONTENT);
        p.weight = 1.0f;

        btnBack = new Button (this);
        btnBack.setText("Back");
        btnBack.setBackgroundColor(Color.parseColor("#f1c40f"));
        btnBack.setGravity(Gravity.CENTER_HORIZONTAL);
        btnBack.setLayoutParams(p);
        btnBack.setOnClickListener(this);

        linearLayout2.addView(btnBack);
        linearLayout1.addView(linearLayout2);
        linearLayout1.addView(sview);

        setContentView(linearLayout1);
    }

    @Override
    public void onClick(View view) {
        btnBack = (Button) view;
        btnBack.setBackgroundColor(Color.parseColor("#2980b9")); //color change
        new CountDownTimer(100, 50) {

            @Override
            public void onTick(long arg0) {
                // TODO Auto-generated method stub
            }

            @Override
            public void onFinish() {
                btnBack.setBackgroundColor(Color.parseColor("#f1c40f")); // original color
            }
        }.start();//end color changed

        finish();
    }
}

Answer 1

您正在添加Button到linearLayout2. 您应该将linearLayout2's宽度更改为MATCH_PARENT

linearLayout2.setLayoutParams(new ViewGroup.LayoutParams(
        ViewGroup.LayoutParams.MATCH_PARENT,
        ViewGroup.LayoutParams.WRAP_CONTENT));

我希望这有帮助。

PS：您可以Button's为按下和选定状态创建选择器，而不是使用计时器来显示按下的按钮效果。这是一个可以帮助您实现此目的的基本链接：android Button Selector