转换TextView-> Bitmap-> ImageView,没有任何显示

Question

我开始一个测试项目只是为了解决这个问题.没有对main.xml的更改.我想创建一个小部件大小的ImageView(80x100),其中包含从TextView转换的位图.是的,这听起来非常迂回,但这只是为了测试; 最后,我希望ImageView有一个背景图像和多个TextViews.我不确定我做错了什么,但没有任何东西被推到屏幕上.

声明TextView/ImageView并在构造函数中传递"this"是一个问题吗？这是我的layoutParams的问题吗？这是代码:

package com.doaf.testproject;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

public class TestProject extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        TextView tv = new TextView(this);
        LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(80, 100);
        tv.setLayoutParams(layoutParams);
        tv.setText("testing 1 2 3");
        tv.setTextColor(0xFFFFFF);
        tv.setBackgroundColor(0x555555);

        Bitmap testB;
        testB = loadBitmapFromView(tv);

        ImageView iv = new ImageView(this);
        iv.setLayoutParams(layoutParams);
        iv.setBackgroundColor(0x555555);
        iv.setImageBitmap(testB);

        setContentView(iv);
    }

    public static Bitmap loadBitmapFromView(View v) {
        Bitmap b = Bitmap.createBitmap(80, 100, Bitmap.Config.ARGB_8888);
        Canvas c = new Canvas(b);
        v.layout(0, 0, 80, 100);
        v.draw(c);
        return b;
    }
}

感谢您的任何帮助,您可以提供.我对Android比较陌生,而且很容易失去这个.

Answer 1

我相信它占据了整个屏幕,因为你没有像Linear Layout这样的容器,它包含一个带有布局约束的ImageView,因此ImageView会扩展以填充可用的屏幕.试试这个:

@Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        TextView tv = new TextView(this);
        LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(80, 100);
        tv.setLayoutParams(layoutParams);
        tv.setText("testing 1 2 3");
        tv.setTextColor(Color.BLACK);
        tv.setBackgroundColor(Color.TRANSPARENT);

        Bitmap testB;

        testB = Bitmap.createBitmap(80, 100, Bitmap.Config.ARGB_8888);
        Canvas c = new Canvas(testB);
        tv.layout(0, 0, 80, 100);
        tv.draw(c);

        ImageView iv = (ImageView)findViewById(R.id.menuIcon);
        iv.setLayoutParams(layoutParams);
        iv.setBackgroundColor(Color.GRAY);
        iv.setImageBitmap(testB);
        iv.setMaxHeight(80);
        iv.setMaxWidth(80);
    }

在你的main.xml文件中:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >

    <ImageView android:id="@+id/menuIcon"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />


</LinearLayout>

我不确定你想要达到什么目标,但我确信有更有效的方法来实现它.