SMALI帮助-从资源获取字符串

Question

我用APKTool反编译了一个apk，在一个.smali文件中，我得到了这样的代码：

.class public Lc/c/a/a;
.super Ljava/lang/Object;
.source "SourceFile"

# instance fields
.field public a:Ljava/lang/String;

# direct methods
.method public constructor <init>()V
    .locals 1

    .line 1
    invoke-direct {p0}, Ljava/lang/Object;-><init>()V

    const-string v0, "Choose Storage"

    .line 2
    iput-object v0, p0, Lc/c/a/a;->a:Ljava/lang/String;

    return-void
.end method

我的问题是我需要从资源文件中获取"const-string，v0“。我尝试添加到字段中，递增本地变量

.field public l:Landroid/content/Context;

然后在"const-string v0“后面添加了下面的代码：

const v1, 0x7f1200a3

iget-object v0, p0, Lc/c/a/a;->l:Landroid/content/Context;

invoke-virtual {v0, v1}, Landroid/content/Context;->getString(I)Ljava/lang/String;

move-result-object v0

但应用程序在这一点上打开时会崩溃。

完全修改的代码

.class public Lc/c/a/a;
.super Ljava/lang/Object;
.source "SourceFile"

# instance fields
.field public a:Ljava/lang/String;

.field public l:Landroid/content/Context;

# direct methods
.method public constructor <init>()V
    .locals 2

    .line 1
    invoke-direct {p0}, Ljava/lang/Object;-><init>()V

    const-string v0, "Choose Storage"

    const v1, 0x7f1200a3

    iget-object v0, p0, Lc/c/a/a;->l:Landroid/content/Context;

    invoke-virtual {v0, v1}, Landroid/content/Context;->getString(I)Ljava/lang/String;

    move-result-object v0

    .line 2
    iput-object v0, p0, Lc/c/a/a;->a:Ljava/lang/String;

    return-void
.end method

来自LOGCAT的错误

java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String andoid.content.Contect.getString(int)' on a null object reference

Answer 1

因为l不是值，所以尝试使用上下文构造。

.class public Lc/c/a/a;
.super Ljava/lang/Object;
.source "SourceFile"

# instance fields
.field public a:Ljava/lang/String;

.field public l:Landroid/content/Context;

# direct methods
.method public constructor <init>(Landroid/content/Context;)V
    .locals 3

    invoke-direct {p0}, Ljava/lang/Object;-><init>()V
    
    #Assign value to l
    iput-object p1, p0, Lc/c/a/a;->l:Landroid/content/Context;
    
    const v0, 0x7f1200a3

    invoke-virtual {p1, v0}, Landroid/content/Context;->getString(I)Ljava/lang/String;

    move-result-object v0

    iput-object v0, p0, Lc/c/a/a;->a:Ljava/lang/String;

    return-void
.end method

就像这样

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