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我是Android开发的初学者，正在尝试开发一个程序，用户可以在按下后将TextView中显示的文本（TextView显示我从资产导入的代码39条码字体文本）转换为位图“转换为位图！” 按钮。我试过在谷歌周围搜索，但我只设法得到像将字符串转换为位图这样的答案，而没有关于在哪里键入代码的指南，所以我对此很困惑。我尝试使用谷歌搜索后尝试输入的代码运行程序，但每次按下转换按钮时它都会崩溃。

真心希望能帮到你！先感谢您！:D

到目前为止，以下是我的代码：-

*根据 Simon 的代码进行了编辑

在爪哇：

public class MainActivity extends Activity 
implements OnClickListener {
    //Called when activity is first created

    TextView tv1;
    ImageView iv;
    Button b;

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

        TextView tv1 = (TextView) findViewById(R.id.txtV);  
        tv1.setDrawingCacheEnabled(true); 

        //To change to code 39 barCode font
        Typeface barcodefont = Typeface.createFromAsset(getAssets(),                 
                "fonts/IDAutomationHC39M_FREE.otf");         
        TextView tv = (TextView) findViewById(R.id.txtV);         
        tv.setTypeface(barcodefont);
    }

    public void onClick(View v) {

        tv1.buildDrawingCache(); 
        iv.setImageBitmap(tv1.getDrawingCache()); 
    } 

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }
}

日志错误：

10-04 06:33:25.076: E/AndroidRuntime(1423): FATAL EXCEPTION: main
10-04 06:33:25.076: E/AndroidRuntime(1423): java.lang.IllegalStateException: Could not find a method ConvertText(View) in the activity class com.example.txtvbitmapconverter.MainActivity for onClick handler on view class android.widget.Button with id 'btnConvert'
10-04 06:33:25.076: E/AndroidRuntime(1423):     at android.view.View$1.onClick(View.java:3578)
10-04 06:33:25.076: E/AndroidRuntime(1423):     at android.view.View.performClick(View.java:4084)
10-04 06:33:25.076: E/AndroidRuntime(1423):     at android.view.View$PerformClick.run(View.java:16966)
10-04 06:33:25.076: E/AndroidRuntime(1423):     at android.os.Handler.handleCallback(Handler.java:615)
10-04 06:33:25.076: E/AndroidRuntime(1423):     at android.os.Handler.dispatchMessage(Handler.java:92)
10-04 06:33:25.076: E/AndroidRuntime(1423):     at android.os.Looper.loop(Looper.java:137)
10-04 06:33:25.076: E/AndroidRuntime(1423):     at android.app.ActivityThread.main(ActivityThread.java:4745)
10-04 06:33:25.076: E/AndroidRuntime(1423):     at java.lang.reflect.Method.invokeNative(Native Method)
10-04 06:33:25.076: E/AndroidRuntime(1423):     at java.lang.reflect.Method.invoke(Method.java:511)
10-04 06:33:25.076: E/AndroidRuntime(1423):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
10-04 06:33:25.076: E/AndroidRuntime(1423):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
10-04 06:33:25.076: E/AndroidRuntime(1423):     at dalvik.system.NativeStart.main(Native Method)
10-04 06:33:25.076: E/AndroidRuntime(1423): Caused by: java.lang.NoSuchMethodException: ConvertText [class android.view.View]
10-04 06:33:25.076: E/AndroidRuntime(1423):     at java.lang.Class.getConstructorOrMethod(Class.java:460)
10-04 06:33:25.076: E/AndroidRuntime(1423):     at java.lang.Class.getMethod(Class.java:915)
10-04 06:33:25.076: E/AndroidRuntime(1423):     at android.view.View$1.onClick(View.java:3571)
10-04 06:33:25.076: E/AndroidRuntime(1423):     ... 11 more
4

2 回答 2

11

尝试这个

添加到您的 onCreate()

tv1.setDrawingCacheEnabled(true);

然后在你的 onClick()

tv1.buildDrawingCache();
iv.setImageBitmap(tv1.getDrawingCache());

http://developer.android.com/reference/android/view/View.html#buildDrawingCache(boolean)

http://developer.android.com/reference/android/view/View.html#getDrawingCache(boolean)

[编辑]

您现在遇到的问题是您试图在 tv1 存在之前启用绘图缓存。

你应该做这个：

TextView tv1 = (TextView) findViewById(R.id.txtV); 
tv1.setDrawingCacheEnabled(true);
于 2012-10-03T06:36:14.700 回答
0

onCreate() 中的行：

TextView tv1 = (TextView) findViewById(R.id.txtV);

应该

tv1 = (TextView) findViewById(R.id.txtV);
于 2020-05-14T18:01:01.630 回答